Introduction to Kinorhyncha and Gnathostomulida Block course on Zoology and Evolution, Biozentrum, Uni. Basel Martin V. Sørensen Associate Professor and curator of microscopic invertebrates Dias 1 Natural History Museum of Denmark
Introduction to Kinorhyncha and Gnathostomulida Taxonomy, biodiversity, morphology, and phylogeny Kinorhyncha, Priapulida, Loricifera, Rotifera, Gnathostomulida and Micrognathozoa Metazoan Phylogeny Curator of Microscopic Invertebrates Martin V. Sørensen Associate Professor and curator of microscopic invertebrates Dias 2 Natural History Museum of Denmark
Ecdysozoa Dias 3 Platyzoa Edgecombe et al. (2011) Higher-level metazoan relationships: Recent progress and remaining questions. Org. Div. Evol.
Platyzoa and Gnathostomulida Gnathifera Platyhelminthes Gastrotricha Gnathostomulida Micrognathozoa Rotifera (Monogononta Acanthocephala - Bdelloidea - Seisonidea) Dias 4
Gnathostomulida: Jaw Worms Marine, interstitial worms, 100 species Dias 5
Gnathostomulida: Jaw Worms Marine, interstitial worms, 100 species Ventral mouth leading to blind gut Dias 6
Gnathostomulida: Jaw Worms Marine, interstitial worms, 100 species Ventral mouth leading to blind gut Simple cephalic sensory organs Simple epidermis with monociliated cells Dias 7
Gnathostomulida: Jaw Worms Marine, interstitial worms, 100 species Ventral mouth leading to blind gut Simple cephalic sensory organs Simple epidermis with monociliated cells Pharynx with hard parts forming jaws Dias 8
Gnathostomulida: Jaw Worms Marine, interstitial worms, 100 species Ventral mouth leading to blind gut Simple cephalic sensory organs Simple epidermis with monociliated cells Pharynx with hard parts forming jaws Dias 9
Gnathostomulida: Jaw Worms Haplognathia lunulifera Gnathostomula paradoxa Rastrognathia macrostoma Problognathia minima Tenuignathia rikerae Haplognathia Dias 10 ruberrima Mesognatharia remanei
Two classes: Filospermoidea Bursovaginoidea Dias 11
Two classes: Filospermoidea Bursovaginoidea Dias 12 Reproductive mode: Hermaphrodite Soft, muscular penis Filiform sperm cells Reproductive mode: Hermaphrodite Sclerotized penis stylet and dwarf sperm Or non-sclerotized penis with giant sperm cells Female organs with bursa
Two classes: Filospermoidea Bursovaginoidea Order: Scleroperalia Ovarium Bursa Testes Penis stylet Dias 13 Spermatozoa
Gnathostomulida: Biology and distribution Sand mixed with detritus Never in mud Never in clean sand, e.g., high energy beaches Dias 14
Gnathostomulida: Jaw Worms Discovered in 1928 by Adolf Remane Found again in the 1950 ies and described in 1956 as a turbellarian order (Ax, 1956) Raised to class level, but still a Platyhelminthes (Ax, 1964) Assigned phylum rank, but with uncertain phylogenetic position (Riedl, 1969) Independently, Ahlrichs (1995) and Rieger & Tyler (1995) do comparative studies of gnathostomulids and rotifers Dias 15
Gnathostomulida: Jaw Worms Rotifera Gnathostomulida Dias 16
Gnathostomulida: Jaw Worms Micrognathozoa Dias 17
Platyzoa and Gnathostomulida Gnathifera Platyhelminthes Gastrotricha Gnathostomulida Micrognathozoa Rotifera (Monogononta Acanthocephala - Bdelloidea - Seisonidea) Dias 18
Dias 19 Kinorhyncha: Mud dragons
Ecdysozoa Dias 20 Platyzoa Edgecombe et al. (2011) Higher-level metazoan relationships: Recent progress and remaining questions. Org. Div. Evol.
Ecdysozoa Kinorhyncha (Mud dragons) Priapulida (Priapulid worms) Loricifera (Girdle wearers) Nematoda (Round worms) Nematomorpha (Gordian worms) Tardigrada (Water bears) Onychophora (Velvet worms) Arthropoda (Arthropods) Dias 21
Kinorhyncha 189 described species Marine, meiobenthic Present from tidal zone to over 7000 m depth Sizes from 130 µm up to 1 mm Are composed of a head, a neck and 11 trunk segments Dias 22
Head Kinorhyncha Neck Trunk Dias 23
Kinorhyncha Mouth cone Introvert Dias 24
Kinorhyncha Neck Placids Dias 25
Kinorhyncha Neck Placids Placids Dias 26
Kinorhyncha Segments Plate junctions Dias 27
Kinorhyncha Segments Plate junctions Dias 28
Kinorhyncha Spines Dias 29
Kinorhyncha Development through 6 juvenile stages Dias 30
Kinorhyncha: Global Biodiversity = only few species reported, or kinorhynch fauna known from a single locality only Dias 31
Kinorhyncha: Korean Biodiversity Program Campyloderes macquariae Condyloderes megastigma C. paradoxus Dracoderes abei D. orientalis Dracoderes n. sp. 1 Echinoderes aspinosus E. aureus E. cernunnos E. koreanus E. microaperturus E. obtuspinosus E. rex E. tchefouensis E. ulsanensis Echinoderes n. sp. 1 Echinoderes n. sp. 2 Kinorhynchus yushini Meristoderes elleae M. glaber M. herranzae M. imugi Meristoderes n. sp. Paracentrophyes anurus Pycnophyes tubuliferus Pycnophyes n. sp. 1 Pycnophyes n. sp. 2 Pycnophyes n. sp. 3 Pycnophyes n. sp. 4 Sphenoderes poseidon Dias 32
Kinorhyncha: Gulf of Mexico Research Initiative Antygomonas n. sp. Echinoderes n. sp. 1 to 11 Echinoderes spinifurca Paracentrophyes n. sp. Pycnophyes n. sp. Sphenoderes n. sp. Dias 33
Ecdysozoa Kinorhyncha (Mud dragons) Priapulida (Priapulid worms) Loricifera (Girdle wearers) Nematoda (Round worms) Nematomorpha (Gordian worms) Tardigrada (Water bears) Onychophora (Velvet worms) Arthropoda (Arthropods) Dias 34
Ecdysozoa Ecdysozoa Scalidophora Nematoida Kinorhyncha Priapulida Loricifera Nematoda Nematomorpha Tardigrada Onychophora Arthropoda Dias 35 Cuticle formed from microvilli tips Molting Ecdysone Loss of locomotory cilia
Ecdysozoa Cycloneuralia Panarthropoda Scalidophora Nematoida Kinorhyncha Priapulida Loricifera Nematoda Nematomorpha Tardigrada Onychophora Arthropoda Ring-shaped brain around pharynx Segmentation of trunk and limbs Dias 36
Cycloneuralia: Scalidophora and Nematoida Scalidophora Nematoida Kinorhyncha Priapulida Loricifera Nematoda Nematomorpha Introvert + mouth cone Scalids Papillar sense organs (flosculi) Protonephridia Unpaired dorsal and ventral nerve strings Loss of circular muscles Loss of sperm flagellum Both sexes with cloaca Vermiform habitus Dias 37
Molecular data does not support Scalidophora Scalidophora 18S rrna Nematoida Kinorhyncha Priapulida Nematoda Loricifera Nematomorpha Introvert + mouth cone Scalids Papillar sense organs (flosculi) Protonephridia Unpaired dorsal and ventral nerve strings Loss of circular muscles Loss of sperm flagellum Both sexes with cloaca Vermiform habitus Dias 38 Plesiomorphies? Adult morphology
Loriciferan Nematomorph sister groups? Loricifera Nematomorpha Dias 39
Loriciferan Nematomorph sister groups? Loricifera Nematomorpha Hexaradial symmetry patterns in pharynx, opposed to pentaradial symmetry patterns in Kinorhyncha and Priapulida Dias 40
Loriciferan Nematomorph sister groups? Loricifera Nematomorpha Evolution through Progenesis?? Progenesis: Evolution through sexual maturation of larval stage, which causes the loss of following preadult and adults stages Dias 41
Loriciferan Nematomorph sister groups? Evolution through Progenese Loss of larva Original cycle maintained Loss of adult stage through progenesis Dias 42
The New Ecdysozoan Phylogeny? Nematomorpha (Gordian worms) Loricifera (Girdle wearers) Nematoda (Round worms) Kinorhyncha (Mud dragons) Priapulida (Priapulid worms) Tardigrada (Water bears) Onychophora (Velvet worms) Arthropoda (Arthropods) Dias 43
Dias 44 Thanks!