CUTTLEFISH. Phylum: Mollusca. Class :Cephalopoda. (It s a not a fish)

Transcription

1 CUTTLEFISH Phylum: Mollusca Class :Cephalopoda (It s a not a fish)

2 CUTTLEFISH CAMOUFLAGE How to avoid becoming this (or a version of this) Chemical Defense Physical Defense Run (or Swim) Fast Hide! Linguine with cuttlefish and ink sauce

3 CUTTLEFISH CAMOUFLAGE Rapid visually mediated changes in SPECIALIZED SKIN PATTERN COLOR TEXTURE

4 CUTTLEFISH CAMOUFLAGE Rapid visually mediated changes in SPECIALIZED SKIN PATTERN COLOR Specialized organs / cells in skin: Chromatophore organs Leucophores Iridophores

5 Cephalopod Chromatophore Organ Diameter of the sacculus expands up to about 7 times its retracted state which is equivalent to an increase in area of about 50 times. From: Tree of Life Cephalopod Chromatophore Authored by Richard E. Young, Michael Vecchione, and Katharina M. Mangold Figure. Cut-away view of a cephalopod chromatophore. Drawing modified from Cloney and Florey, Cloney, R. A. and E. Florey Ultrastructure of cephalopod chromatophore organs. Zeits. für Zellforsch. 89:

6 The leucophore reflects whatever color of light illuminates it. There is no color discrimination and no effect on the color by the angle of illumination. Under white light the leucophores appear to be white. The leucophores, therefore, simply produce scattered reflection of ambient light. From: Tree of Life Leucophores Authored by Richard E. Young and Michael Vecchione. Cloney, R. A. and S. L. Brocco Chromatophore organs, reflector cells, iridocytes and leucophores in cephalopods. Amer. Zool., 23:

7 iridophores (short arrows) above the chromatophore (long arrow) Iridophores reflect and polarize light by layers of intracellular platelets that are positioned parallel to each other. The spectrum (color) of the reflection can change from red/pink to blue and depends upon the distance between platelets, the orientation of the platelets, and the direction of viewing N. Shashar, D. T. Borst, S. A. Ament, W. M. Saidel, R. M. Smolowitz and R. T. Hanlon Polarization Reflecting Iridophores in the Arms of the Squid Loligo pealeii. Biol. Bull. 201:

8 CAMOUFLAGE

9 PATTERN Visually mediated pattern matching cues: CONTRAST Size of objects

10 PATTERN Mäthger L. M., A. Barbosa, S. Miner, and R. T. Hanlon Color blindness and contrast perception in cuttlefish (Sepia officinalis) determined by a visual sensorimotor assay. Vision Res. 46:

11 PATTERN Disruptive coloration is shown in response to checks that are 40% and 120% of the area of the cuttlefish s White square component. Non disruptive body patterns (uniform and mottle) are shown on other check sizes. White square Barbosa, A., L. M. Mäthger, C. Chubb, C. Florio, C. Chiao, and R. T. Hanlon Disruptive coloration in cuttlefish: a visual perception mechanism that regulates ontogenetic adjustment of skin patterning. The Journal of Experimental Biology 210:

12 VISION Vertebrate eye with ciliary photoreceptor cells Cephalopod eye with microvillar photoreceptor cells Land, M. F. and D. E. Nilsson Animal Eyes. Oxford University Press., Inc. New York, USA.

13 VISION Photopigment = OPSIN (protein) + Chromophore (11- cis retinal)

14 COLOR VISION Land, M. F. and D. E. Nilsson Animal Eyes. Oxford University Press., Inc. New York, USA.

15 COLOR VISION? Cuttlefish on blue and yellow checkerboard (matched in intensity) as well as uniformly blue and yellow substrates; no disruptive pattern was elicited. Mäthger L. M., A. Barbosa, S. Miner, and R. T. Hanlon Color blindness and contrast perception in cuttlefish (Sepia officinalis) determined by a visual sensorimotor assay. Vision Res. 46:

16 COLORBLIND COLOR MATCHING Cuttlefish on test substrates Do cuttlefish color match? Mäthger, L. M., Chiao, C. C., Barbosa, A., Hanlon, R. T Color matching on natural substrates in cuttlefish, Sepia officinalis. Journal of Comparative Physiology A, 194 (6):

17 COLORBLIND COLOR MATCHING Mäthger, L. M., Chiao, C. C., Barbosa, A., Hanlon, R. T Color matching on natural substrates in cuttlefish, Sepia officinalis. Journal of Comparative Physiology A, 194 (6):

18 COLORBLIND COLOR MATCHING Fig. 3 a Animal on substrate S1. Six blue dots are approximate locations of spectral measurements on the animal, and 10 blue dots are representative sampling locations of the substrate around the animal. Reflectance spectra measured on the b animal and c substrate Mäthger, L. M., Chiao, C. C., Barbosa, A., Hanlon, R. T Color matching on natural substrates in cuttlefish, Sepia officinalis. Journal of Comparative Physiology A, 194 (6):

19 COLORBLIND COLOR MATCHING Principal Component Analysis (PCA) Mäthger, L. M., Chiao, C. C., Barbosa, A., Hanlon, R. T Color matching on natural substrates in cuttlefish, Sepia officinalis. Journal of Comparative Physiology A, 194 (6):

20 COLORBLIND COLOR MATCHING Principal Component Analysis (PCA) al_components.pdf Lindsay I Smith A tutorial on Principal Components Analysis

21 COLORBLIND COLOR MATCHING Mäthger, L. M., Chiao, C. C., Barbosa, A., Hanlon, R. T Color matching on natural substrates in cuttlefish, Sepia officinalis. Journal of Comparative Physiology A, 194 (6):

22 Visually mediated color matching cue: Reflectance (Irradiance/Intensity) COLORBLIND COLOR MATCHING not reliable by itself so vision gets assists from: Limited number of skin pigments Pigments adapted to have similar reflectance to substrates found in natural habitat Leucophores and Iridophores reflecting ambient light Decreased impact of wavelength with depth

23 COLORBLIND CAMOUFLAGE COLORBLIND COLOR MATCHING PATTERN MATCHING Both benefit from limited but highly adapted repertoires TEXTURE MATCHING