Article. Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California, 90007, USA 3

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1 Zootaxa 2603: 1 52 (2010) Copyright 2010 Magnolia Press Article ISSN (print edition) ZOOTAXA ISSN (online edition) A new genus and new species of fan worms (Polychaeta: Sabellidae) from Atlantic and Pacific Oceans the formal treatment of taxon names as explanatory hypotheses JOÃO MIGUEL DE MATOS NOGUEIRA 1,3, KIRK FITZHUGH 2 & MAÍRA CAPPELLANI SILVA ROSSI 1 1 Departamento de Zoologia, Instituto de Biociências, Universidade de São Paulo, R. do Matão, travessa 14, n. 101, , São Paulo, SP, Brazil 2 Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California, 90007, USA 3 Corresponding author. nogueira@ib.usp.br Table of contents Abstract... 2 Resumo... 2 Introduction... 2 Material and methods... 3 Results... 4 Systematics... 4 Family Sabellidae Latreille, Subfamily Sabellinae Latreille, Sabellomma gen. nov Sabellomma minuta comb. nov Sabellomma collinae spec. nov Sabellomma harrisae spec. nov Methyl green staining pattern Comparisons between species of Sabellomma gen. nov Replacement of the generic name Kirkia Nogueira, López and Rossi, Discussion The Phylogenetic Hypothesis, Sabellomma Conclusions Acknowledgments References Accepted by P. Hutchings: 23 Jul. 2010; published: 6 Sep

2 Abstract Members of Parasabella minuta Treadwell, 1941, subsequently moved to Perkinsiana, were collected during a survey of rocky intertidal polychaetes along the state of São Paulo, Brazil. Additional specimens, which are referred to two new species, were also found in similar habitats from the Bocas del Toro Archipelago, Caribbean Panama, and Oahu Island, Hawaii. A phylogenetic analysis of Sabellinae, including members of P. minuta and the two new species, provided justification for establishing a new generic hypothesis, Sabellomma gen. nov., for these individuals. Formal definitions are also provided for Sabellomma minuta gen. nov., comb. nov., S. collinae gen. nov., spec. nov., and S. harrisae gen. nov., spec. nov., along with descriptions of individuals to which these hypotheses apply. The generic name Aracia nom. nov., is provided to replace Kirkia Nogueira, López and Rossi, 2004, pre-occupied by a mollusk. Key words: Sabellomma, Aracia, Sabellinae, Sabellidae, Polychaeta, new genus, systematics, taxonomy Resumo Espécimes de Parasabella minuta Treadwell, 1941, subsequentemente transferida para Perkinsiana, foram coletados durante um levantamento dos poliquetas da zona entremarés de costões rochosos ao longo do Estado de São Paulo, Brasil. Espécimes semelhantes, atribuídos a duas espécies novas para a ciência, foram também encontrados em habitats similares no arquipélago de Bocas Del Toro, na costa atlântica do Panamá, e na Ilha de Oahu, Havaí. Uma análise filogenética de Sabellinae, incluindo membros de P. minuta e das duas espécies novas justificou estabelecer uma nova hipótese genérica, Sabellomma gen. nov., para estes indivíduos. São também aqui fornecidas definições para Sabellomma minuta gen. nov., comb. nov., S. collinae gen. nov., sp. nov., e S. harrisae gen. nov., sp. nov., bem como descrições dos indivíduos aos quais tais hipóteses se aplicam. O nome Aracia nom. nov. é fornecido em substituição a Kirkia Nogueira, López e Rossi, 2004, pré-ocupado por um molusco. Introduction Several recent surveys of the shallow-water polychaete faunas from Brazil, Panama, and the Hawaiian Islands, have revealed the presence of Sabellinae 1 polychaetes that exhibit an unusual combination of characters that do not allow for association with any of the current genera. For instance, the specimens have interramal eyespots typical of the clade containing Sabella Linnaeus, 1767, Sabellastarte Krøyer, 1856, Bispira Krøyer, 1856, Branchiomma Köllicker, 1859, Pseudobranchiomma Jones, 1962, and Stylomma Knight-Jones, 1997 (Fitzhugh 1989; Rouse and Fitzhugh 1994; Fitzhugh and Rouse 1999; Capa 2007), and also present among members of Myxicola Koch in Renier, 1847 (Fitzhugh pers. obs), as well as members of at least one species of Demonax Kinberg, 1867 (Capa pers. comm.) and Megalomma (Tovar-Hernandez and Salazar-Vallejo 2008; Capa and Murray 2009; see below). Yet the arrangements and types of thoracic notoand abdominal neurochaetae are typical of what are seen outside the Sabella et al. clade. As well, radioles have unpaired, simple eyespots along lateral margins, reminiscent of those among members of Notaulax Tauber, 1879, Hypsicomus Grube, 1870, and Anamobaea Krøyer, As a consequence of these observations and the results of our phylogenetic analyses we present in this paper the definition of a new genus to accommodate these individuals. The Brazilian specimens are members of a previously named 1. In their phylogenetic analysis of the Sabellidae-Serpulidae clade, based only on nucleotide sequence data and a very limited representation from among members of taxa, Kupriyanova & Rouse (2008) inferred the following relationships: (Sabellinae (Fabriciinae, Serpulidae)). The authors concluded that since the Sabellidae s.l. is paraphyletic, the most efficacious solution is to raise the Fabriciinae to the level of family, i.e. Fabriciidae, thus limiting the Sabellidae s.s. to the equivalent Sabellinae. While Kupriyanova & Rouse do make reference to available morphological studies (cf. Fitzhugh 1989, 1998; Rouse & Fitzhugh 1994; Fitzhugh & Rouse 1999), those available data were not incorporated into their analysis. The inherent difficulty with data exclusion, extensively outlined by Fitzhugh (2006a, b), is that there is no epistemic basis for choosing between hypotheses derived from different, mutually relevant sets of data. Thus, we chose the more conservative route in the present paper of following hypotheses based on morphological data available for the considerably wider range of Sabellidae s.l. taxa, i.e. (Serpulidae (Sabellinae, Fabriciinae)), until such time as available nucleotide data are collated with morphological data for the purpose of inferring sabelliform phylogenetic hypotheses. 2 Zootaxa Magnolia Press NOGUEIRA ET AL.

3 species, Perkinsiana minuta (Treadwell, 1941), while the Panamanian and Hawaiian specimens are members of two new species. Perkinsiana minuta (as Parasabella Bush, 1905) was originally based on the description of a single specimen from the Island of São Sebastião, Brazil. As part of her revision of Sabellidae, Knight-Jones (1983) transferred the species to Perkinsiana Knight-Jones, 1983, after examination of the holotype. Knight-Jones noted the presence of radiolar eyespots but did not observe interramal eyespots since pigmentation associated with those structures had subsequently faded in the holotype (see below). Perkinsiana was erected to accommodate members of several species in Sabellinae which did not fit well in the definitions of genera in which they had been placed (Knight-Jones 1983). The definition of Perkinsiana is, however, problematic, as was noted by Fitzhugh (1989), who pointed out that it only relies upon plesiomorphic characters. Not surprisingly, several subsequent phylogenetic analyses (e.g. Rouse & Fitzhugh 1994; Fitzhugh & Rouse 1999; Fitzhugh 2003; Capa 2007) have found the genus to be poly- or paraphyletic. For the purpose of presenting the systematic relationships of these polychaetes, we will employ principles outlined by Fitzhugh (2005a, b, 2006a, b, c, 2008a, b, c, 2009) for the treatment of all taxa as explanatory hypotheses. As noted by Fitzhugh (2008b), while this approach most accurately reflects the actions of systematists in the context of scientific inquiry, there are substantial implications for the formal naming of any of these hypotheses, as well as the formal definitions of those names. For instance, the ICZN (1999: Article , Recommendation 13A) is non-committal as to what is meant by the term taxon, and as a consequence allows for taxa to be recognized solely on the basis of characters that differentiate the taxon. As we will show in this paper, neglecting the actual intent of biological systematics by the ICZN (1999), in lieu of essentially equating taxa with classes of organisms, results in a contradiction that allows for the formal naming of phylogenetic and specific hypotheses that are not definable. In more colloquial parlance, the recognition of names, or taxa, where there are no associated autapomorphies. The present paper also has a second, minor objective, which is to formally replace the generic name, Kirkia Nogueira, López, & Rossi, Nogueira et al. (2004) transferred Perkinsiana riwo Rouse, 1996 to Kirkia, whose type species is K. heterobranchiata Nogueira, López & Rossi, Subsequent to the publication of this genus, it was determined that the name is preoccupied by a mollusk genus. Material and methods The material included in the present paper came from three independent studies, the projects Biodiversity of Polychaetes on Rocky Shores Along the Coast of the State of São Paulo, Brazil, Census of Coral Reef Ecosystems (CReefs): Understudied Species and the Biodiversity of French Frigate Shoals, Northwestern Hawaiian Islands, Papahanaumokuakea Marine National Monument, and a taxonomic survey of marine invertebrates from Bocas del Toro Archipelago, Atlantic coast of Panama. In the state of São Paulo, specimens were collected along most of the coast (622 km), from intertidal rocky shores, at peaks of low tide. Specimens were removed from scrapings of tufts of algae, sponges, ascidians, and fragments of sabellariid reefs. Collected material was examined using a stereo microscope, with polychaetes sorted, relaxed in menthol solution, then fixed in 4% seawater-formalin, subsequently washed and preserved in 70% ethanol. Collections in Hawaii were taken from shallow, sublittoral depth using scuba, from sand and coral rubble bottoms. Specimens were sorted live using a stereo microscope, photographed, fixed in 5% seawaterformalin, then rinsed in freshwater and transferred to 70% ethanol. Panamanian material was obtained by snorkeling at shallow depths, from coral rubble. Broken rubble was fixed en masse in 5% seawater-formalin, and the polychaetes were subsequently sorted using a stereo microscope, then washed and transferred to 70% ethanol. Further examinations using stereo and compound light microscopy were made on entire specimens and detached chaetae and uncini were permanently mounted on slides in polyvinyl-lactophenol (PVLP). Measurements of uncinal proportions were made as follows: height from tip of crest to lowest part of base; length (or length of handle) from tip of handle to tip of breast. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 3

4 For examination using SEM, specimens were dehydrated in an ethanol series, transferred to hexamethyldisilazane (HMDS), and allowed to air dry. Specimens were then mounted on aluminum stubs, coated with gold-palladium, and examined using a Hitachi S-3000N scanning electron microscope at the Natural History Museum of Los Angeles County (NHMLAC). Photos using light microscopy were taken with a Canon EOS 5D digital camera attached to a Leica MZ12 stereo microscope and a Leitz Laborlux S compound microscope and edited with Adobe Photoshop CS software. The holotype of Sabellomma minuta gen. nov., comb. nov., was borrowed from the American Museum of Natural History (AMNH), additional specimens examined for the present study were deposited at Natural History Museum of Los Angeles County (NHMLAC/LACM-AHF), both institutions in the USA, and Museu de Zoologia, Universidade de São Paulo (MZUSP), and Museu de Zoologia, Universidade Estadual de Campinas (ZUEC), both latter institutions in Brazil. Type material of S. collinae gen. nov., sp. nov., was deposited at the NHMLAC, two additional specimens previously assigned to Perkinsiana minuta by Knight- Jones (1983) were examined at the United States National Museum, Smithsonian Institution (USNM). Type material of S. harrisae gen. nov., sp. nov., was deposited at the NHMLAC and the Bernice Pauahi Bishop Museum (BPBM), Hawaii, USA; additional specimens examined for the present study were found among sabellids borrowed from the BPMB. Results Systematics Family Sabellidae Latreille, 1825 Subfamily Sabellinae Latreille, 1825 Sabellomma gen. nov. Type species. Parasabella minuta Treadwell, Definition. A phylogenetic hypothesis, accounting for presence of unpaired, simple eyespots along entire lengths of outer radiole margins. Unpaired, simple eyespots originated by an unspecified mechanism(s) in a reproductively isolated population of individuals with no eyespots, subsequent to which the character became fixed in the population by an unspecified mechanism(s), followed by population splitting events, leading to individuals to which specific hypotheses S. minuta gen. nov., comb. nov., S. harrisae gen. nov., sp. nov., and S. collinae gen. nov., sp. nov., also apply. Sabellomma gen. nov., is an ad hoc hypothesis (homoplasy), as the presence of unpaired, simple eyespots distributed along the entire lengths of radioles is also an autapomorphy for the specific-level hypothesis, Sabella cerasina Grube, 1870 (see The Phylogenetic Hypothesis, Sabellomma, below). An additional synapomorphy, also an instance of homoplasy, is subsumed by this hypothesis in one transformation series interramal eyespots which is also a synapomorphy for the clade containing Stylomma, Bispira, Sabella, Sabellastarte, Branchiomma, Pseudobranchiomma (see The Phylogenetic Hypothesis, Sabellomma, below), and also present in Myxicola. Collective characteristics of individuals to which Sabellomma gen. nov., applies. Small- to mediumsized individuals, with 4 9 pairs of radioles; most specimens with 4 5 thoracic chaetigers. Radioles without palmate membrane; outer margins with numerous, irregularly distributed, lensed eyespots, usually more numerous in areas with pigmented bands across radioles. Dorsal lips with radiolar appendages, associated radiolar skeleton absent; pinnular appendages present or absent; distally rounded ventral lips, continuing ventrally as parallel lamellae with ventral sacs, and lamellae terminating between collar ventral lappets. Dorsal-most margins of branchial lobes with thickened ridges. Posterior peristomial ring collar only covering branchial lobes; dorsal margins well separated from faecal groove; one pair of triangular, non-overlapping 4 Zootaxa Magnolia Press NOGUEIRA ET AL.

5 ventral lappets. Interramal, simple ocelli in all chaetigers, especially evident in abdomen. Collar chaetae elongate, narrowly hooded, arranged in two oblique rows, ventral row chaetae shorter than dorsal; remaining thoracic notopodia with superior arc of elongate, narrowly hooded chaetae, inferior chaetae as two rows of mucronate paleae. Thoracic neuropodia with avicular uncini about as long as high, crest with 4 5 irregular rows of teeth, extending for less than one-half extension of main fang; companion chaetae with rounded denticulate heads and long, drop-shaped, slightly asymmetrical membranes. Abdominal notopodia with avicular uncini similar to thoracic or with shorter handles; abdominal neuropodia with two rows of elongate, narrowly hooded chaetae, anterior row of chaetae shorter than posterior. Pygidium triangular, distally blunt; eyespots present. Remarks. While the synapomorphy, albeit homoplasious (see Definition above) to which Sabellomma refers is the presence of unpaired, simple eyespots along the outer margins of radioles, and possibly also interramal eyespots (see The Phylogenetic Hypothesis, Sabellomma, below), it is conceivable that the thorax composed of less than eight chaetigers might also be accounted for in this hypothesis. The latter condition is, however, also known among individuals to which Branchiomma and Pseudobranchiomma also apply, but causal accounts of this condition have not yet been presented among Sabellinae. The presence of thickened ridges at the dorsal margins of branchial lobes might be a synapomorphy of Sabellomma, but this character is only visible using SEM (Figs 2C, F G; 8A, D; 12D, I) and we have not been able to confirm these observations with light microscopy. The radiolar eyespots are lensed units, irregularly distributed along each outer, lateral radiolar margin, usually more numerous in areas with pigmented bands across radioles. Among individuals to which the three specific hypotheses will be applied below, no significant differences in the number and distribution of eyespots were observed. In his revision of Demonax, Perkins (1984) described individuals of D. microphthalmus (Verrill, 1873) as having radiolar eyespots arranged similar to that found in Sabellomma. However, all specimens of D. microphthalmus we examined, including material from close to the type-locality, have pigment spots along radioles, but no indication these are eyespots. If, on the other hand, members of D. microphthalmus do have eyespots, this condition would be an autapomorphy, albeit homoplasious, accounted for by the specific hypothesis. Giangrande (1994: 230, fig. 1) described members of D. tommasi as having large lenticular eyes showing an irregular arrangement. In the absence of phylogenetic hypotheses for Demonax, it is unknown if radiolar eyes is plesiomorphic for the genus. In addition to the presence of interramal eyespots among members of Myxicola, Sabellomma, and the clade comprising Stylomma, Bispira, Sabella, Sabellastarte, Branchiomma, and Pseudobranchiomma, Tovar- Hernandez and Salazar-Vallejo (2008: Figs 1E-G, 2C-D; see also Capa and Murray [2009]) described interramal eyespots among members of Megalomma carunculata, and M. Capa (pers. comm.) has observed this character among members of an undescribed Demonax species. Based on the phylogenetic hypotheses inferred by Capa and Murray (2009: fig. 13), interramal eyespots is not a plesiomorphic condition for Megalomma. As with radiolar eyes, noted earlier, there is no way at present to know if interramal eyespots is plesiomorphic for Demonax. Sabellomma minuta comb. nov. (Figs 1 6, 16A F; Table 1) Parasabella minuta Treadwell, 1941: 4, Figs Perkinsiana minuta.- Knight-Jones, 1983: , Fig. 19A M. Material examined. Holotype (AMNH 2894) and 22 specs, all from the northern coast of the state of São Paulo, Brazil. Holotype coll. Ilha de São Sebastião, city of Ilhabela. Ubatuba: Picinguaba, in algae, shallow subtidal: algal frond 2, 8 Oct 2001: spec. 1 (MZUSP 1045); algal frond 4, 8 Apr 2001: spec. 2 (LACM-AHF POLY 2395); algal frond 5: spec. 3 (MZUSP 1046); algal frond 6: spec. 4 (ZUEC-POL 7442); algal frond 7: specs 5 7, spec. 5 (LACM-AHF POLY 2396), spec. 6 (LACM-AHF POLY 2397), spec. 7 (ZUEC-POL A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 5

6 7443); algal frond 10: specs 8 11, spec. 8 (LACM-AHF POLY 2398), spec. 9 (LACM-AHF POLY 2399), spec. 10 (LACM-AHF POLY 2400), spec. 11 (discarded); algal frond 11, 8 Jun 2001: spec. 12 (LACM-AHF POLY 2401); algal frond 12: spec. 13 (LACM-AHF POLY 2402); algal frond 17: spec. 14 (MZUSP 1047); algal frond 19: specs 15 17, spec. 15 (MZUSP 1048), spec. 16 (ZUEC-POL 7444), spec. 17 (MZUSP 1049). São Sebastião: Praia de São Francisco, 19 Apr 2003, intertidally, in rocks: specs 18 20, spec. 18 (MZUSP 1050), spec. 19 (ZUEC-POL 7445), spec. 20 (LACM-AHF POLY 2403); Praia da Baleia, algal frond 4: spec. 21 (ZUEC-POL 7446); islands in front of Praia da Baleia, in Sargassum, shallow subtidal, 10 Apr 2003, fronde 3: spec. 22 (MZUSP 1051). Details of holotype and specs are provided in Table 1. FIGURE 1. Sabellomma minuta gen. nov., comb. nov. A: entire specimen, left ventro-lateral view; B D: entire specimen, ventral, ventral and left lateral views, respectively; E, G: anterior end, ventral views; F: anterior end, right lateral view; H: posterior end, right ventro-lateral view. A, C D, F H from spec. 18 (MZUSP 1050), B, E from holotype (AMNH 2894). Scale bars: A D = 2 mm; E G = 0.7 mm; H = 0.5 mm. 6 Zootaxa Magnolia Press NOGUEIRA ET AL.

7 FIGURE 2. Sabellomma minuta gen. nov., comb. nov. A: total worm, right lateral view; B: anterior end, left lateral view; C: anterior end, dorsal view; D: anterior end, left lateral view; E: dorsal lip (dissected crown); F G: details of base of crown; H: anterior end, right lateral view; I J: details of anterior end, ventral view. br = branchial ridge; ci = ciliated patch; dl = dorsal lip; pa = pinnular appendage; pl = parallel lamellae; ra = radiolar appendage; vs = ventral sacs. Photos A D, F J from spec. 10 (LACM-AHF 2400); photo E from spec. 20 (LACM-AHF 2403). Scale bars: A B = 0.5 mm; C = 0.3 mm; D, H = 0.4 mm; E, I = 75 µm; F = 0.1 mm; G = 40 µm; J = 80 µm. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 7

8 FIGURE 3. Sabellomma minuta gen. nov., comb. nov. A: middle part of radiole; B: collar chaetae; C: notochaetae from segment 3; D: neurochaetae from segment 10; E: neurochaetae from segment 3; F: uncini from segment 10; G: neurochaetae from segment 4; H: uncini from segment 18. Photos B C, E, G H from spec. 19 (ZUEC-POL 7445); photos D and F from spec. 10 (LACM-AHF 2400). Scale bars: A = 60 µm; B C, E, G = 30 µm; D = 40 µm; F, H = 20 µm. Additional material. São Sebastião, Praia de São Francisco, 16 Jul 2003, intertidal, on rocks: 9 specs. Definition. Two possibilities, depending on character transformation series in the phylogenetic hypothesis involving individuals to which Sabellomma collinae spec. nov., S. minuta comb. nov., and S. harrisae spec. nov. refers (see Remarks on Specific-level Hypotheses in Sabellomma): (1) A specific hypothesis, accounting for the presence of pinnular appendages fused for almost entire length to dorsal lips among observed individuals. Pinnular appendages almost completely fused to dorsal lips originated by an unspecified 8 Zootaxa Magnolia Press NOGUEIRA ET AL.

9 mechanism(s) in a reproductively isolated population of individuals with pinnular appendages only proximally fused to dorsal lips, subsequent to which the new character became fixed in the population by an unspecified mechanism(s), leading to individuals observed in the present, all with pinnular appendages almost entirely fused to dorsal lips. (2) There are no autapomorphies to provide a basis for the specific hypothesis. As is discussed below (see Remarks on Specific-level Hypotheses in Sabellomma), the formal definition of S. minuta as an explanatory hypothesis is tenuous since the explanation of pinnular appendages completely fused to dorsal lips is not an autapomorphy in some transformation series (see also Definition for S. harrisae, below). FIGURE 4. Sabellomma minuta gen. nov., comb. nov. A: collar chaetae; B: notochaetae from segment 2; C: notochaetae from segment 5; D: neurochaetae from segment 6; E F: inferior thoracic notochaetae (paleae) from segments 3 and 5, respectively; G: detail of neurochaetae from anterior row from segment 6. All photos from spec. 10 (LACM-AHF 2400). Scale bars: A, D = 30 µm; B = 40 µm; C = 20 µm; E = 9 µm; F = 12 µm; G = 15 µm. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 9

10 FIGURE 5. Sabellomma minuta gen. nov., comb. nov. A: neurochaetae from segment 2; B D: companion chaetae from segments 2, 4 and 2, respectively; E F: uncini from segment 4; G: anterior abdominal uncini; H: mid-abdominal uncini; I: posterior abdominal uncini; J: uncini from segment 2. All photos from spec. 10 (LACM-AHF 2400). Scale bars: A = 20 µm; B C = 8 µm; D, F G, J = 5 µm; E = 9 µm; H I = 6 µm. 10 Zootaxa Magnolia Press NOGUEIRA ET AL.

11 FIGURE 6. Sabellomma minuta gen. nov., comb. nov. A: inferior thoracic notochaetae (paleae) from segment 3; B: neurochaetae from segment 3; C: neurochaetae from segment 9; D: uncini from segment 9. All photos from holotype (AMNH 2894). Scale bars: A C = 60 µm; D = 40 µm. Description. Measurements. Medium-sized individuals; crown mm long, 5 8 pairs of radioles (Table 1). Complete specimens with trunk mm long (holotype longer but incomplete), mm wide, 3 6 thoracic chaetigers (most with 4 5), abdominal chaetigers (Table 1). Pigmentation. Live specimens with radioles alternating pink and white bands, associated with dark green and pink pinnules, radiolar tips and associated pinnules white; anterior body brown, small interramal eyespots throughout (Fig. 1A). After preservation, anterior body pigmentation and interramal eyespots frequently conspicuous, crown with up to 7 brownish bands, alternating with white bands, pinnules mostly white or with fainted pigmentation (Fig. 1B G). Crown. Radiolar flanges and palmate membrane both absent. Each radiole with four rows of skeletal cells. Radioles with one irregular row of eyespots along each lateral margin; eyespots as single units, each with large lens, more numerous along distal two-thirds to one-half of radioles, especially in association with transverse pigment bands (Figs 1F G; 3A), less abundant near radiolar tips. Dorsal lips about one-fifth total crown length, basally broad, distally tapering, with radiolar appendages lacking internal skeletal cells; single pinnular appendage almost completely joined by thin membrane to each dorsal lip (Fig. 2E). Ventral lips low, distally rounded, each continuing ventrally as parallel lamella with large ventral sac above collar ventral lappets (Figs 1G; 2B, D, H J). Mid-dorsal margins of branchial lobes as thickened ridges, extending anteriorly along dorsal-most pair of radioles (Fig. 2C, F G). A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 11

12 TABLE 1. Morphological variation among the specimens of Sabellomma minuta gen. nov., comb. nov. examined for the present study (variation within parentheses is only shown when there is difference from one side of the body to the other). Number of segments Holotype (AMNH 2894) Spec. 1 (MZUSP 1045) Spec. 2 (LACM-AHF POLY 2395) Spec. 3 (MZUSP 1046) Spec. 4 (ZUEC-POL 7442) Spec. 5 (LACM-AHF POLY 2396) Spec. 6 (LACM-AHF POLY 2397) Spec. 7 (ZUEC-POL 7443) Size length of crown; body length x width (mm) Number of pairs of radioles (left; right sides of crown) Thorax (left; right sides of body) Abdomen (left; right sides of body) 3; 13 (incomplete) x 0.8 8; ; 37 Slides (segments) Additional data Thorax: notochaetae (paleae) and neurochaetae: 3 Abdomen: neurochaetae and uncini: 9 2.5; 3.6 x ~0.7 6; (incomplete) - ~3; 3 x 0.6 7; (incomplete) - 1.8; ~2.5 x (regenerating) ~2; ~5 x 0.8 7; ~3; 4.7 x (regenerating) - 2.5; 6 x ; 2.5 x (incomplete) - Holotype in relatively good state of preservation, with fainted but conspicuous radiolar eyespots. Body pigmentation, including interramal eyespots, all faded off, not visible. Photographed for Figs 1B, E; 6A D Incomplete, in good state of preservation. Crown with very fainted but still visible pigmented bands and conspicuous radiolar eyespots; body devoid of pigmentation, except for interramal eyespots Incomplete, in relatively good state of preservation. Crown with very fainted pigmented bands and conspicuous radiolar eyespots; body devoid of pigmentation, except for fainted interramal eyespots Complete, in good state of preservation. Radiolar pigmentation faded and inconspicuous, except for few radiolar eyespots and light pigmentation at base of crown. Interramal ocelli conspicuous, small Complete, in good state of preservation. Body and crown nearly devoid of pigmentation, including radiolar and interramal eyespots Complete, in good state of preservation, regenerating posterior body from segment 19. Well preserved radiolar pigmentation; body devoid of pigmentation, except for interramal eyespots Complete, in good state of preservation, slightly damaged at beginning of abdomen. Crown with fainted but conspicuous pigmented bands and conspicuous radiolar eyespots; body devoid of pigmentation, except for fainted interramal eyespots Incomplete, in good state of preservation, with radioles on left side of crown cut at midlength to expose lips. Crown with fainted pigmented bands and conspicuous radiolar eyespots; body devoid of pigmentation, except for fainted interramal eyespots continued next page 12 Zootaxa Magnolia Press NOGUEIRA ET AL.

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15 Body. Collar fused to body dorso-laterally, well separated from faecal groove, extending anteriorly to level of first pair of parapodia; laterally low, slightly oblique, covering bases of radiolar crown but not origins of radioles; ventrally with one pair of triangular, distally pointed, non-overlapping lappets reaching anterior margin of chaetiger 1, separated from each other by short parallel lamellae; ventrally, between termination of parallel lamellae and anterior margin of first ventral shield, ciliated patch present (Figs 1B E, G; 2A D, F J). Trapezoidal ventral shields, indented by neuropodia on thorax; anterior margin of first shield medially indented (Figs 1B C, E G; 2B, D, H). Mid-dorsal faecal groove deep on anterior chaetigers (Fig. 2C, F). Collar chaetae narrowly hooded, arranged in two rows (Figs 2A D, F, H, J; 3B, 4A); subsequent thoracic notopodia with narrowly hooded superior chaetae, arranged in arc, inferior chaetae paleate, with long, gently tapering tips, arranged in two rows partially enclosed by superior arc (Figs 2 A D, H, J; 3C; 4B C, E F). Thoracic neuropodia with avicular uncini about as long as high, crest with 4 5 irregular rows of secondary teeth, covering proximal half of main fang, breast distinct, not extending distally to tip of main fang (Figs 3E, G; 5A, E F); companion chaetae with rounded, symmetrical, denticulate heads and long, tear drop-shaped, slightly asymmetrical, gently tapering membranes (Figs 3E; 5A D). Abdominal neuropodia with narrowly hooded chaetae, arranged in two rows, anterior row with shorter chaetae (Figs 3D; 4D, G). Anterior abdominal uncini similar to thoracic (Figs 3F; 5G), from mid-abdomen uncini with similar number of rows of secondary teeth (Fig. 5H J), but with shorter handles (Fig. 3H). Triangular, distally rounded pygidium, with 1 3 small, red ocelli at each lateral margin (Figs 1H, 16K). Remarks on holotype. The holotype is relatively well preserved, but most pigmentation of the crown and body is faded and inconspicuous, including that of interramal eyespots, except for conspicuous radiolar eyespots on most radioles. Radiolar eyespots were noticed by both Treadwell (1941) and Knight-Jones (1983), although in her diagnosis of Perkinsiana, Knight-Jones (1983) stated that radiolar eyes are absent among members of the genus. Knight-Jones (1983) examined the holotype and made slides of a thoracic and an abdominal chaetiger. All data about the holotype provided by Knight-Jones is accurate, except for some misinterpretations. Thoracic notopodial paleae (Fig. 6A), and abdominal neuro- (Fig. 6C) and notochaetae (Fig. 6D) of the holotype are like those of recently collected specimens. Although Knight-Jones (1983) stated that abdominal neurochaetae are similar in length throughout, they do vary along the body; the holotype has longer chaetae in posterior rows starting in mid-abdominal segments. The only real discrepancy between the redescription provided by Knight-Jones (1983) and in this paper is in regards to the lengths of handles in thoracic uncini, which, according to Knight-Jones drawing (1983: 286, Fig. 19G), is about twice the length of distance between breast and crest. However, the slide of thoracic neurochaetae of the holotype made by Knight-Jones has the torus of segment 3 split into three pieces and in two of them the shafts of companion chaetae completely cover the handles of uncini, not allowing for proper evaluation of their length, and in the third piece only a few uncini have visible handles, which are clearly much shorter than the shafts of companion chaetae (Fig. 6B). The holotype is also much longer than any of the other specimens examined in the present study (Table 1), but the presence of a short thorax and radiolar eyespots, together with the fact that it was collected on São Sebastião Island, which is across a 2 km wide channel from the beaches where our specimens were collected, give us confidence that the hypothesis Sabellomma minuta applies to all of the specimens. In addition, the area has been extensively surveyed for more than five years and the only other Sabellinae specimens found with a short thorax are members of Pseudobranchiomma paraemersoni Nogueira, Rossi & López, Variation. The specimens of Sabellomma minuta examined for the present study presented great variation in size and crown/body pigmentation (Table 1). Since these conditions have not yet been compared to what exists in live specimens, it is not possible to discount the effects of preservation. The range of variation in numbers of thoracic chaetigers is 3 6 among observed specimens (Table 1). This variation might reflect the consequences of regeneration subsequent to scissiparity (Knight-Jones & Bowden 1984; Fitzhugh 2003; Nogueira & Knight-Jones 2003; Nogueira et al. 2004), especially considering the amount of variation between left and half sides of the body in number of radioles and body segments, which we believe is also due to imperfect regeneration. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 15

16 Distribution. This species is only known to occur off the northern coast of the State of São Paulo, Brazil. Previous records by Knight-Jones (1983) from the Caribbean are herein assigned to S. collinae spec. nov., (see below). Sabellomma collinae spec. nov. (Figs 7 10, 16G K; Table 2) Material examined. Holotype and 8 paratypes coll. 7 Aug 2003, shallow subtidal (3.05 m) coral-sponge rubble, by G. Hendler, K. Fitzhugh, J. Sanchez, W. Keel, at south side of Cayo Swan (= Isla de Pájaros) (9.453 o N 82.3 o W), Bahia Almirante, Bocas del Toro Archipelago, Bocas del Toro Province, Caribbean side of Panamá. All type material deposited at the NHMLAC (holotype: LACM-AHF POLY 2404; paratypes: LACM-AHF POLY ). Details of each spec. of type series are provided in Table 2. Additional specimens. USNM : Puerto Rico, Caribbean Sea, 1 spec.; USNM : Key West, Florida, USA, 1 spec. Comparative material examined. Demonax microphthalmus (CB T ; 39027): 1 spec. Slides: radiole; notochaetae, chaetiger 7; uncini, chaetiger 7. Definition. Two possibilities, depending on character transformation series in the phylogenetic hypothesis involving individuals to which Sabellomma collinae spec. nov., S. minuta, and S. harrisae spec. nov., refers (see Remarks on Specific-level Hypotheses in Sabellomma): (1) A specific hypothesis, accounting for the absence of dorsal lip pinnular appendages among observed individuals. Dorsal lips without pinnular appendages originated by an unspecified mechanism(s) in a reproductively isolated population of individuals with pinnular appendages almost completely fused to dorsal lips, subsequent to which the new character became fixed in the population by an unspecified mechanism(s), leading to individuals observed in the present, all with dorsal lips lacking pinnular appendages. (2) There are no autapomorphies to provide a basis for the specific hypothesis. As is discussed below (see Remarks on Specific-level Hypotheses in Sabellomma), the formal definition of S. collinae as an explanatory hypothesis is tenuous since the explanation of the absence of pinnular appendages is not an autapomorphy in some transformation series. Description. Measurements. Medium-sized individuals; crown 1 3 mm long, with 4 9 pairs of radioles (Table 2). Complete specimens with trunk 2 10 mm long, mm wide, with 4 5 thoracic, and abdominal chaetigers (Table 2). Pigmentation. Living specimens not observed. Except for radiolar and interramal eyespots, body unpigmented or with very faint brownish pigmentation at base of crown and up to 4 5 radiolar bands. Small interramal eyespots present in all chaetigers, frequently faint and inconspicuous (Fig. 7L). Crown. Radiolar flanges and palmate membrane both absent. Each radiole with four rows of skeletal cells. Radioles with two irregular rows of eyespots along lateral margins; eyespots as single units, each with large lens, more numerous along distal-most two thirds to one-half of radioles, especially in association with transverse pigment bands (Fig. 7E K), less abundant near radiolar tips. Dorsal lips about one-fifth total crown length, basally broad, distally tapering, with radiolar appendages lacking internal skeletal cells; pinnular appendage absent (Fig. 8F). Ventral lips low, distally rounded, each continuing ventrally as parallel lamella with large ventral sac above collar ventral lappets (Figs 7A, C G, I K; 8B C, E, G H). Mid-dorsally, branchial lobes with thickened ridges extending along dorsal-most pair of radioles (Fig. 8A, D). Body. Collar fused to body dorso-laterally, well separated from faecal groove, extending anteriorly to level of first pair of parapodia; laterally low, slightly oblique, covering bases of radiolar crown but not origins of radioles; ventrally with one pair of triangular, distally pointed, non-overlapping lappets reaching anterior margin of chaetiger 1, separated from each other by short parallel lamellae; ventrally, between termination of parallel lamellae and anterior margin of first ventral shield, ciliated patch present (Figs 7A K; 8A E, G H). Trapezoidal ventral shields, posteriorly indented by neuropodia on thorax, anterior margin of first shield medially indented (Figs 7D E, J K; 8B C, G H). Mid-dorsal faecal groove deep on anterior chaetigers (Figs 7B, H; 8A, D). Collar chaetae narrowly hooded, arranged in two rows (Fig. 9A); subsequent thoracic 16 Zootaxa Magnolia Press NOGUEIRA ET AL.

17 FIGURE 7. Sabellomma collinae gen. nov., sp. nov. A: total worm, left lateral view; B: total worm, dorsal view; C: total worm, right lateral view; D: total worm, ventral view; E: anterior end, ventral view; F: anterior end, left ventro-lateral view; G: anterior end, left lateral view; H: anterior end, dorsal view; I: anterior end, right lateral view; J: detail of anterior end, ventral view; K: detail of anterior end, left ventro-lateral view; L: anterior to mid-abdominal segments; M: posterior end, right lateral view. All photos from holotype (LACM-AHF 2404). vs = ventral sacs. Scale bars: A D = 1 mm; E I, K = 0.7 mm; J = 0.4 mm; L M = 0.3 mm. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 17

18 FIGURE 8. Sabellomma collinae gen. nov., sp. nov. A: anterior end, dorsal view; B: anterior end, left lateral view; C: anterior end, ventral view; D: detail of anterior end, dorsal view; E: detail of anterior end, left lateral view; F: dorsal lip (dissected crown); G H: details of collar and base of crown, ventral view; I: posterior end, left lateral view. Unspecified arrows point to ciliated patch; bp = basalmost pinnule; br = branchial ridge; dl = dorsal lip; pl = parallel lamellae; ra = radiolar appendage; vs = ventral sacs. Photos A E, G H from paratype 7 (LACM-AHF 2411); photo F from paratype 6 (LACM-AHF 2410). Scale bars: A B = 0.4 mm; C E = 0.2 mm; F G, I = 0.1 mm; H = 60 µm. 18 Zootaxa Magnolia Press NOGUEIRA ET AL.

19 FIGURE 9. Sabellomma collinae gen. nov., sp. nov. A: collar chaetae; B: notochaetae from segment 4; C: neurochaetae from segment 13; D: notochaeta from anterior row from segment 13; E: notochaeta from posterior row from segment 13; F: neurochaetae from segment 4; G H: uncini from segment 15. All photos from paratype 6 (LACM-AHF 2410). Scale bars: A B, D = 30 µm; C, E = 25 µm; F = 20 µm; G H = 10 µm. notopodia with narrowly hooded superior chaetae, arranged in arc, inferior notochaetae paleate, with long, gently tapering tips, arranged in two rows partially enclosed by superior arc (Figs 8A E; 9B; 10A B). Thoracic neuropodia with slightly higher than long avicular uncini, crest with 4 5 irregular rows of secondary teeth, covering proximal half of main fang, breast distinct, not extending distally to tip of main fang (Figs 9F; 10E, G H); companion chaetae with rounded, symmetrical, denticulate heads and long, tear drop-shaped, slightly asymmetrical, gently tapering membranes (Figs 9F; 10E, G, I K). Abdominal neuropodia with narrowly hooded chaetae, arranged in two rows, anterior row with shorter chaetae (Figs 9C E; 10C D). Abdominal uncini similar to thoracic (Figs 9G H; 10F). Triangular, distally rounded pygidium, with 1 3 small, red ocelli at each lateral margin (Figs 7M; 8I). Variation. The specimens of S. collinae sp. nov., examined for the present study presented considerable variation in size, but most other characters did not vary between specimens (Table 2). One specimen (paratype 7), probably a juvenile, has a different number of radioles in right and left halves of the crown. All specimens have the same numbers of thoracic and abdominal noto- and neuropodia on both sides of the body, but there is also slight variation in the number of thoracic chaetigers, the holotype and paratype 7 having 4 thoracic chaetigers, all other specimens having 5 (Table 2). All this may indicate the occurrence of asexual reproduction by scissiparity, as said above for S. minuta. Etymology. This species is named for Dr. Rachel Collin, director of the Bocas del Toro Marine Station, Smithsonian Tropical Research Institute, Panama, who coordinated the Panamanian survey. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 19

20 FIGURE 10. Sabellomma collinae gen. nov., sp. nov. A: notochaetae from segment 4; B: inferior thoracic notochaetae (paleae) from segment 2; C D: mid-abdominal neurochaetae; E: neurochaetae from segment 3; F: mid-abdominal uncini; G: neurochaetae from segment 2; H: uncini from segment 3; I K: companion chaetae from segments 4, 3 and 2, respectively. All photos from paratype 6 (LACM-AHF 2410). Scale bars: A = 30 µm; B = 10 µm; C D = 12 µm; E = 20 µm; F = 5 µm; G H = 8 µm; I, K = 4 µm; J = 2 µm. 20 Zootaxa Magnolia Press NOGUEIRA ET AL.

21 TABLE 2. Morphological variation among the type-series of Sabellomma collinae gen. nov., sp. nov. (variation within parentheses is only shown when there is difference from one side of the body to the other). Holotype (LACM-AHF 2404) Paratype 1 (LACM-AHF 2405) Paratype 2 (LACM-AHF 2406) Paratype 3 (LACM-AHF 2407) Paratype 4 (LACM-AHF 2408) Paratype 5 (LACM- AHF 2409) Size length of crown; body length x width (mm) Number of pairs of radioles (left; right sides of crown) Number of segments Thorax Abdomen Slides (segments) Additional data 3; ~10 x Complete, in good state of preservation. Base of crown with fainted pigmentation below origin of radioles; some radioles with brownish band at ¾ of their extension; eyespots more numerous on distal half of radioles. Body devoid of pigmentation, except for fainted interramal eyespots. Photographed for Fig. 7A M, then methyl green stained and photographed again for Fig. 16G K ~1.5; 3 x ~ Complete, in good state of preservation. Crown and body almost completely devoid of pigmentation, except for very few and fainted radiolar eyespots, and slightly more conspicuous interramal eyespots ~1; ~2.2 x ~ Complete, with faded, nearly inconspicuous pigmentation throughout, very few radiolar eyespots and interramal eyespots still visible ~1.5; ~2 x (regenerating) - Complete, regenerating posterior end. Crown with faded pigmentation on basal fifth, few faded, still visible pigmented bands and conspicuous radiolar eyespots; body devoid of pigmentation, except for conspicuous interramal eyespots 1.5; 2.2 x (incomplete) - Fragment in poor state of preservation. All crown, including radiolar eyespots, and body pigmentation faded and inconspicuous, except for very fainted, barely visible interramal eyespots ~3; 4 x (incomplete) - Incomplete, in good state of preservation. Crown with fainted but conspicuous basal pigmentation, some pigmented bands still visible and numerous radiolar eyespots. Body devoid of pigmentation, except for fainted interramal eyespots continued next page A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 21

22 TABLE 2. (continued) Paratype 6 (LACM-AHF 2410) Paratype 7 (LACM-AHF 2411) Paratype 8 (LACM-AHF 2412) Size length of crown; body length x width (mm) Number of pairs of radioles (left; right sides of crown) Number of segments Thorax Abdomen Slides (segments) ~3; 9 x Thorax: notochaetae: 1, 2, 3, 4; uncini: 3, 4 Abdomen: neurochaetae: 13; uncini: 13, 15 Additional data Complete, in good state of preservation, but crown detached from body and body damaged for the extraction of chaetae. Crown with 4 short pigmented bands, eyespots more numerous on middle third of radioles, distal third without eyespots in most radioles. Crown halves separated from each other, both mounted on SEM stub. Interramal eyespots small and fainted throughout, only conspicuous on anterior and mid-abdominal segments. Body methyl green stained. Photographed for Figs 8F; 9A H; 10A K ~1; ~2.5 x ; Complete, mounted on SEM stub. Crown with few radiolar eyespots, body with conspicuous interramal eyespots throughout. Photographed for Figs 8A E, G H; ~2.5; 4 x ~31 - Complete, cut in two pieces at beginning of abdomen and mounted on SEM stub. Crown with two brownish bands, eyespots more numerous on distal half of radioles. Body devoid of pigmentation, except for small, fainted interramal eyespots 22 Zootaxa Magnolia Press NOGUEIRA ET AL.

23 Distribution. Knight-Jones (1983) assigned to S. minuta specimens with short thorax from Florida (Key West) and Puerto Rico. We have examined those specimens and, although the generic characters of Sabellomma are conspicuous, they do not present dorsal pinnular appendages. Therefore, those specimens are here referred to S. collinae and this species is considered to occur throughout the Caribbean. Sabellomma harrisae spec. nov. (Figs 11 15, 17; Table 3) Material examined. Holotype and 18 paratypes coll. 9 Oct 2006, in shallow subtidal coral rubble, by Leslie Harris et al., near Keelii Lagoon and Sand Island Pacific ( o N, o W), Honolulu Harbour, Oahu, Hawaii. Holotype (LACM-AHF POLY 2413) and 15 paratypes (LACM-AHF POLY ) deposited at the NHMLAC; 3 paratypes deposited at the BPBM (BPBM-R ). Details of each spec. of type series are provided in Table 3. Additional material. Bernice Pauahi Bishop Museum. BPBM 1283: coll. Honolulu Harbour pier 3 4, Sta. 1, 20 Aug 1997, 3 complete specs plus 4 incomplete specs. BPBM 1237: coll. Honolulu Harbour pier 27, Sta. 7, 23 Sep 1997, 1 complete spec. BPBM 1224: coll. Honolulu Harbour Sealand pier, Sta. 15, 05 Nov 1997, 1 incomplete spec. Definition. Two possibilities, depending on character transformation series in the phylogenetic hypothesis involving individuals to which Sabellomma minuta and S. harrisae spec. nov., refers (see Remarks on Specific-level Hypotheses in Sabellomma): (1) A specific hypothesis, accounting for the presence of pinnular appendages proximally fused to dorsal lips among observed individuals. The character of proximally fused dorsal lip pinnular appendages originated by an unspecified mechanism(s) in a reproductively isolated population of individuals with pinnular appendages completely fused to dorsal lips, subsequent to which the character became fixed in the population by an unspecified mechanism(s), leading to individuals observed in the present, all with pinnular appendages proximally fused to dorsal lips. (2) There are no autapomorphies to provide a basis for the specific hypothesis. As is discussed below (see Remarks on Specific-level Hypotheses in Sabellomma), the definition of S. harrisae is tenuous since the explanation of pinnular appendages partially fused to dorsal lips is not an autapomorphy in some transformation series. Description. Measurements. Medium-sized individuals; crown mm long; 5 8 pairs of radioles, number of radioles often different in left and right halves of crown (Table 3). Complete specimens with trunk mm long, mm wide; 4 5 thoracic and 21 ~50 abdominal chaetigers, often with different numbers of thoracic chaetigers in left and right sides of body (Table 3). Pigmentation. Live specimens with bright pink radioles alternating lighter and darker pigmented bands, distal one-fifth greenish to brownish; anterior body pink, progressively less pigmented posteriorly, beige to light brown (Fig. 11A B). Crown of preserved specimens with reddish brown pigmentation in proximal onefifth, then alternating white and reddish brown bands (Fig. 11C I). Anterior segments with reddish brown pigmentation around noto- and neuropodia, dorso-laterally lighter and well marked ventrally, on ventral shields; from segment 6, pigmentation progressively lighter (Fig. 11C I); small, conspicuous interramal eyespots throughout (Fig. 11E G, J). Crown. Radiolar flanges and palmate membrane both absent. Each radiole with four rows of skeletal cells. Radioles with two irregular rows of eyespots along lateral margins (Fig. 11C I); eyespots as single units, each with large lens, more numerous along distal two thirds to one-half of radioles, especially in association with transverse pigmented bands (Fig. 11C I), less abundant near radiolar tips. Dorsal lips less than one-fifth total crown length; basally broad, distally tapering, with radiolar appendages lacking internal skeletal cells; single pinnular appendage present, distal one-half free (Fig. 12C, J). Ventral lips low, distally rounded, each continuing ventrally as parallel lamella with large ventral sac above collar ventral lappets (Fig. 12C, E, H). Mid-dorsal margins of branchial lobes as thickened ridges, extending along dorsal-most pair of radioles (Fig. 12D, I). A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 23

24 FIGURE 11. Sabellomma harrisae gen. nov., sp. nov. A B: live specimens; C: total worm, dorsal view; D: total worm, ventral view; E: total worm, right lateral view; F: anterior end, right lateral view; G: detail of anterior end, right lateral view; H: anterior end, dorsal view; I: anterior end, ventral view; J: posterior end, left ventro-lateral view. Photos A B from paratype 11 (LACM-AHF POLY 2424; no track for other specs in photo B), courtesy L. Harris; photos C J from holotype (LACM-AHF 2413). Scale bars: C E = 0.5 mm; F = 0.4 mm; G, J = 0.2 mm; H I = 0.3 mm. 24 Zootaxa Magnolia Press NOGUEIRA ET AL.

25 FIGURE 12. Sabellomma harrisae gen. nov., sp. nov. A: anterior end, right lateral view; B: anterior end, left lateral view; C: dissected half crown and lips; D: anterior end, dorsal view; E: anterior end, ventral view; F: anterior end, left lateral view; G: anterior end, right lateral view; H I: details of collar and base of crown, right ventro-lateral and dorsal views, respectively; J: dorsal lip (dissected crown); unspecified arrow points to connection between dorsal lip and dorsal pinnular appendage. br = branchial ridge; dl = dorsal lip; pa = pinnular appendage; pl = parallel lamellae; ra = radiolar appendage; vs = ventral sacs. Photos A B, D I from paratype 6 (LACM-AHF 2419); photos C and J from paratype 12 (LACM-AHF 2425). Scale bars: A, C = 0.3 mm; B = 0.4 mm; D, F G = 0.1 mm; E, I = 75 µm; H, J = 50 µm. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 25

26 FIGURE 13. Sabellomma harrisae gen. nov., sp. nov. A: collar chaetae; B: notochaetae from segment 3; C: superior thoracic notochaetae from segment 3; D: inferior thoracic notochaetae (paleae) from segment 3; E: neurochaetae from segment 12; F G: uncini from segment 3; H: companion chaetae from segment 3; I: uncini from segment 10. All photos from paratype 10 (LACM-AHF 2423). Scale bars: A E = 30 µm; F, H = 8 µm; G = 15 µm; I = 10 µm. Body. Collar fused to body dorso-laterally, well separated from faecal groove, extending anteriorly to level of first pair of parapodia; laterally low, slightly oblique, covering bases of radiolar crown but not origins of radioles; ventrally with one pair of triangular, distally blunt, non-overlapping lappets reaching anterior margin of chaetiger 1, separated from each other by short parallel lamellae (Figs 11A, C I; 12A B, D I); ventrally, between termination of parallel lamellae and anterior margin of first ventral shield, ciliated patch present (Fig. 12H). Trapezoidal ventral shields, posteriorly indented by neuropodia on thorax (Figs 11D, F G, I; 12A, E, G H), anterior margin of first shield medially indented (Figs 11I; 12E, H). Mid-dorsal faecal groove deep on anterior chaetigers (Figs 11C, H; 12B, D, F, I). Collar chaetae narrowly hooded, arranged in two rows (Figs 12B, D, F, I; 13A; 14A B); subsequent thoracic notopodia with narrowly hooded superior chaetae, arranged in arc, inferior chaetae paleate, with long, gently tapering tips, arranged in two rows partially enclosed by 26 Zootaxa Magnolia Press NOGUEIRA ET AL.

27 FIGURE 14. Sabellomma harrisae gen. nov., sp. nov. A: parapodia from segments 1 2; B: collar chaetae; C: notochaetae from segment 4; D F: inferior thoracic notochaetae (paleae) from segments 3, 4 and 4, respectively; G, J: posterior abdominal neurochaetae; H I: mid-abdominal neurochaetae. All photos from paratype 6 (LACM-AHF 2419). Scale bars: A = 40 µm; B, G H, J = 20 µm; C = 25 µm; D = 15 µm; E = 5 µm; F = 7 µm; I = 8 µm. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 27

28 FIGURE 15. Sabellomma harrisae gen. nov., sp. nov. A: neurochaetae from segment 4; B: uncini from segment 3; C: companion chaetae from segment 3; D E: uncini from segment 6; F, J: anterior abdominal uncini; G I: posterior abdominal uncini. All photos from paratype 6 (LACM-AHF 2419). Scale bars: A = 15 µm; B = 8 µm; C = 3 µm; D, G, J = 4 µm; E, I = 5 µm; F, H = 2 µm. 28 Zootaxa Magnolia Press NOGUEIRA ET AL.

29 TABLE 3. Morphological variation among the type-series of Sabellomma harrisae gen. nov., sp. nov. (variation within parentheses is only shown when there is difference from one side of the body to the other). Number of segments Holotype (LACM-AHF 2413) Paratype 1 (LACM-AHF 2414) Paratype 2 (LACM-AHF 2415) Paratype 3 (LACM-AHF 2416) Paratype 4 (LACM-AHF 2417) Size Length of crown; body length x width (mm) Number of pairs of radioles (left; right sides of crown) Thorax (left; right sides of body) Abdomen (left; right sides of body) Slides (segments) ~2; ~4.4 x ~40-2.5; 5 x 0.5 8; 7 4; ~3; 7 x ~3; 5 x ~0.5 6; ~1.8; 3.5 x ~ Additional data Complete, in good state of preservation. Crown pigmentation dark red, well preserved at base and along radioles, on pigmented bands and radiolar eyespots; body pigmentation as dark reddish area laterally and ventrally on collar and thorax, extending on ventral shields until beginning of posterior body, dorsally lighter, restricted to thorax; conspicuous interramal eyespots throughout. Photographed for Fig. 11C J Complete, in good state of preservation. Crown pigmentation dark red, well preserved at base and along radioles, on pigmented bands and radiolar eyespots; body pigmentation as dark reddish area laterally and ventrally on collar and thorax, extending on ventral shields until beginning of posterior body, dorsally lighter, restricted to thorax; conspicuous interramal eyespots throughout Complete, in good state of preservation. Crown pigmentation well preserved at base and along radioles, on pigmented bands and radiolar eyespots; body pigmentation as dark reddish area laterally and ventrally on collar and segment 1, progressively lighter along thorax, present on ventral shields until 4 th 5 th abdominal segment; small and fainted, but conspicuous interamal eyespots throughout. Methil green stained and photographed for Fig. 17E F Complete, in good state of preservation. Crown pigmentation well preserved at base and along radioles, on pigmented bands and radiolar eyespots; body pigmentation as light reddish area laterally and ventrally on collar and segment 1, around neuropodia until end of thorax; fainted, still conspicuous interramal eyespots throughout Complete, in good state of preservation, almost cut in two pieces at segment 10 and possibly regenerating posterior segments. Crown pigmentation dark red, well preserved at base and along radioles, on pigmented bands and radiolar eyespots; body pigmentation as dark reddish area laterally and ventrally on collar and thorax, extending on ventral shields until around segment 14 15, dorsally lighter, extending until segment 10 11; conspicuous interramal eyespots throughout continued next page A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 29

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33 superior arc (Figs 12A B, D G; 13B D; 14A, C F). Thoracic neuropodia with avicular uncini about as long as high, crest with 4-5 rows of secondary teeth, covering proximal half of main fang; breast distinct, not extending distally to tip of main fang (Figs 13F G; 15A B); companion chaetae with rounded, symmetrical, denticulate heads and long, tear drop-shaped, slightly asymmetrical, gently tapering membranes (Figs 13H; 15A, C). Abdominal neuropodia with narrowly hooded chaetae, arranged in two rows, anterior row with shorter chaetae (Figs 13E; 14G J). Abdominal uncini similar to thoracic, but with shorter handle (Figs 13I; 15D J). Triangular, distally rounded pygidium, with 1 3 small, red ocelli at each lateral margin (Fig. 11J). Variation. The specimens of Sabellomma harrisae examined for the present study do not present remarkable variation, including size (Table 3). However, several specimens exhibit variation from one side of the body to the other in terms of number of radioles, thoracic and abdominal segments, or both (Table 3), possibly indicating reproduction by scissiparity, as said above. Etymology. We dedicate this species to Leslie Harris, Collection Manager of the Polychaete Collection at the NHMLAC, who was responsible for the collection of this material, photographed it alive and was the first to study these specimens. Distribution. Sabellomma harrisae is only known from Oahu Island, Hawaii. Methyl green staining pattern Members of the three species of Sabellomma exhibit similar pattern of methyl green staining. Ventral shields stain intensely, together with scattered spots around neuropodia throughout and dorsally on abdomen (Figs 16A K; 17A F). The first ventral shield stains more intensely than any other structure and the stain takes longer to faint in ethanol (Fig. 17A B). In the three species there is some intraspecific variation in regards to the staining pattern on pygidium, with specimens on which it stains intensely (Fig. 16A B, E G, K; 17E F), while in other it does not stain (Fig. 17A B, D). Comparisons between species of Sabellomma gen. nov. Sabellomma is a very conservative genus in regards to the type and distribution of radiolar eyespots, collar morphology, thoracic notochaetae, abdominal neurochaetae and uncini throughout, body length (although members of S. harrisae seem to be slightly smaller), number of thoracic chaetigers (Tables 1 3) and distribution of glandular areas, shown by the methyl green staining pattern. Members of the three species of the genus differ mostly in pigmentation, especially in live specimens, and in the presence/absence of pinnular appendages and extent to which those appendages are fused to dorsal lips. Living specimens of Sabellomma minuta have radioles with alternating pink and white bands, with white tips, and green and pink pinnules (Fig. 1A), and a greenish-brown body, which is darker on anterior segments. After preservation, crown pigmentation is frequently well preserved, but the pigment of original pink bands retracts towards both tips of each band, so that each original pink band generates two pigmented bands separated from each other by a white band. In addition, preserved pigmentation changes from pink to brown (Fig. 1A G). Trunk pigmentation, however, is almost always lost in preservation (Table 1), with specimens usually pale, except for pigmentation associated with interramal eyespots. In the case of Sabellomma collinae live material was not observed, but preserved specimens are largely unpigmented, except for interramal eyespots and a few specimens have remnants of pigmented radiolar bands (Fig. 7A M; Table 2). Live specimens of Sabellomma harrisae have bright pink crowns, with alternating lighter and darker bands, and brownish radiolar tips. The trunk is pink anteriorly, then light brown (Fig. 11A B). After preservation, most crown and body pigmentation is usually preserved, but brownish (Fig. 11C J; Table 3). A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 33

34 FIGURE 16. Methyl green staining. Sabellomma minuta gen. nov., comb. nov. (spec. 16 [ZUEC-POL 7444], photographed after ~2 hours in ethanol after immersion in methyl green solution). A: total worm, ventral view; B: total worm, dorsal view; C D: anterior end, ventral views; E: posterior end, ventral view; F: posterior end, dorsal view. Sabellomma collinae gen. nov., sp. nov. (holotype [LACM-AHF 2404], photographed after ~2.5 hours in ethanol after immersion in methyl green solution). G: total worm, right lateral view; H: anterior end, dorsal view; I J: anterior end, ventral views; K: posterior end, right lateral view. Scale bars: A B, G = 1 mm; C, I = 0.7 mm; D F, K = 0.3 mm; H, J = 0.4 mm. In addition to pigmentation in life, the species of Sabellomma also differ in the extension of uncinial handles in proportion to distance between breast and crest, but those differences are slight and strongly dependent on the angle through which uncini are observed under light microscopy. Replacement of the generic name Kirkia Nogueira, López and Rossi, 2004 The genus Kirkia was described by Nogueira et al. (2004) for an unusual sabellid which broods eggs in cocoons attached to the dorsalmost pair of radioles. Although the entire coast of São Paulo has been extensively studied for more than five years, the type species, K. heterobranchiata, is only known from Praia do Araçá, a beach on the northern coast of the State of São Paulo, southeastern Brazil, on which it has been 34 Zootaxa Magnolia Press NOGUEIRA ET AL.

35 collected in three different occasions. However the generic name Kirkia is preoccupied by a genus of Mollusca described by Pollonera (1909) and it has another homonym, a genus of Diptera described by Gedoelst (1914). Therefore, the generic name of this sabellid is herein changed from Kirkia to Aracia nom. nov., in reference to the type-locality of A. heterobranchiata comb. nov. As suggested by Nogueira et al. (2004), Aracia includes a second species, A. riwo (Rouse, 1996) comb. nov., from Papua New Guinea. FIGURE 17. Methyl green staining. Sabellomma harrisae gen. nov., sp. nov. A B: total worm; C: anterior end, ventral view; D: posterior end, ventral view; E: total worm, left lateral view; F: posterior end, dorsal view. Photos A D from spec. BPBM 1237, after ~2.5 hours in ethanol after immersion in methyl green solution; photos E F from paratype 2 (LACM-AHF 2415), after ~24 hours in ethanol after immersion in methyl green solution. Scale bars: A = 0.6 mm; B = 1 mm; C, F = 0.3 mm; D = 0.4 mm; E = 0.7 mm. A NEW GENUS OF SABELLINAE Zootaxa Magnolia Press 35