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Does the tunic nipple array serve to camouflage diurnal salps?

Published online by Cambridge University Press:  17 March 2015

Euichi Hirose ,
Daisuke Sakai ,
Tomohiro Shibata ,
Junji Nishii ,
Hiroyuki Mayama ,
Akihiro Miyauchi  and
Jun Nishikawa
Euichi Hirose*
Affiliation:
Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
Daisuke Sakai
Affiliation:
Department of Electrical and Electronic Engineering, Kitami Institute of Technology, 165 Koen-cho, Kitami, Hokkaido 090-8507, Japan
Tomohiro Shibata
Affiliation:
Research Institute for Electronic Science, Hokkaido University, Kitaku, Sapporo, Hokkaido 001-0020, Japan
Junji Nishii
Affiliation:
Research Institute for Electronic Science, Hokkaido University, Kitaku, Sapporo, Hokkaido 001-0020, Japan
Hiroyuki Mayama
Affiliation:
Department of Chemistry, Asahikawa Medical University, Midorigaoka-Higashi, Asahikawa 078-8510, Japan
Akihiro Miyauchi
Affiliation:
Hitachi Research Laboratory, Hitachi Ltd., Omika, Hitachi, Ibaraki 319-1292, Japan
Jun Nishikawa
Affiliation:
Department of Marine Biology, School of Marine Science and Technology, Tokai University, 3-20-1, Orido, Shimizu, Shizuoka 424-8610, Japan
*
Correspondence should be addressed to: E. Hirose, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan email: euichi@sci.u-ryukyu.ac.jp
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Abstract

The salp Thalia rhomboides is distributed in the shallow depths during the day, and is thus at increased risk of predation by visual predators and from the damaging effects of ultraviolet (UV) radiation compared with species distributed in deeper layers in the daytime. The integument (tunic) of T. rhomboides may have adaptive optical properties, but the absorption spectra of the unfixed tunic demonstrate that the tunic transmits UV as well as visible light, indicating that the tunic is not an effective barrier against UV radiation. Ultrastructural observation revealed that the surface of the tunic cuticle is covered in a nipple array consisting of hemispherical protuberances approximately 40 and 30 nm in diameter in solitary and aggregate zooids, respectively. Simulation of light reflection of a nipple array using rigorous coupled wave analysis (RCWA) indicated that the reflection is slightly lower for the nipple array than for a flat surface at high angles of incidence (θ > 80°). This result supports the idea that the nipple array serves to make the salp less visible. The simulation also indicated that the height and distribution of the salp nipple array do not have an optimal structure for causing an antireflection effect. A mechanical restriction might exist on the structures, and the nipple array could also serve another function. The size and distribution of nipples may be controlled by the need to meet the complex requirements of multiple essential functions.

Keywords

antireflectionnipple arrayrigorous coupled wave analysis (RCWA)tunic cuticleultrastructureUV
Type
Research Article
Information
Journal of the Marine Biological Association of the United Kingdom , Volume 95 , Issue 5 , August 2015 , pp. 1025 - 1031
Copyright
Copyright © Marine Biological Association of the United Kingdom 2015 

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References

REFERENCES

Bernhard, C.G. (1967) Structural and functional adaptation in a visual system. Endeavour 26, 79–84.Google Scholar
Gagnon, Y.L., Shashar, N., Warrant, E.J. and Johnsen, S.J. (2007) Light scattering by selected zooplankton from the Gulf of Aqaba. Journal of Experimental Biology 210, 3728–3735.CrossRefGoogle ScholarPubMed
Gibbons, M.J. (1997) Vertical distribution and feeding of Thalia democratica on the Agulhas Bank during March 1994. Journal of the Marine Biological Association of the United Kingdom 77, 493–505.CrossRefGoogle Scholar
Hausen, H. (2005) Comparative structure of the epidermis in polychaetes (Annelida). Hydrobiologia 535/536, 25–35.CrossRefGoogle Scholar
Hirose, E., Kimura, S., Itoh, T. and Nishikawa, J. (1999) Tunic morphology and cellulosic components of pyrosomas, doliolids, and salps (Thaliacea, Urochordata). Biological Bulletin 196, 113–120.CrossRefGoogle ScholarPubMed
Hirose, E., Lambert, G., Kusakabe, T. and Nishikawa, T. (1997) Tunic cuticular protrusions in ascidians (Chordata, Tunicata): a perspective of their character-state distribution. Zoological Science 14, 683–689.CrossRefGoogle Scholar
Hirose, E., Mayama, H. and Miyauchi, A. (2013) Does the aquatic invertebrate nipple array prevent bubble adhesion? An experiment using nanopillar sheets. Biology Letters 9, 20130552.CrossRefGoogle ScholarPubMed
Hirose, E., Ohtsuka, K., Ishikura, M. and Maruyama, T. (2004) Ultraviolet absorption in ascidian tunic and ascidian-Prochloron symbiosis. Journal of the Marine Biological Association of the United Kingdom 84, 789–794.CrossRefGoogle Scholar
Holland, N.D. (1984) Echinodermata: epidermal cells. In Bereiter-Hahn, J., Matoltsy, A.G. and Richards, K.S. (eds) Biology of the integument, 1. Invertebrates. Berlin: Springer, pp. 756–774.CrossRefGoogle Scholar
Iseto, T. and Hirose, E. (2010) Comparative morphology of the foot structure of four genera of Loxosomatidae (Entoprocta): implications for foot functions and taxonomy. Journal of Morphology 271, 1185–1196.CrossRefGoogle ScholarPubMed
Johnsen, S. (2003) Lifting the cloak of invisibility: the effect of changing optical conditions on pelagic crypsis. Integrative and Comparative Biology 43, 580–590.CrossRefGoogle ScholarPubMed
Kashkina, A.A. (1986) Feeding of fishes on salps (Tunicata: Thaliacea). Journal of Ichthyology 26, 57–64.Google Scholar
Kuwabara, K. and Miyauchi, A. (2008) High-aspect-ratio nanopillar structures fabricated by nanoimprinting with elongation phenomenon. Journal of Vacuum Science & Technology B 8, 582–584.CrossRefGoogle Scholar
Madin, L.P., Kremer, P. and Hacker, S. (1996) Distribution and vertical migration of salps (Tunicata, Thaliacea) near Bermuda. Journal of Plankton Research 18, 747–755.CrossRefGoogle Scholar
Nielsen, C. and Jespersen, A. (1997) Entoprocta. In Harrison, F.W. and Woollacott, R.M. (eds) Microscopic anatomy of invertebrates, Volume 13. New York, NY: Wiley, pp. 13–43.Google Scholar
Nishikawa, J. and Tsuda, A. (2001) Diel vertical migration of the pelagic tunicate, Salpa thompsoni in the Southern Ocean during the austral summer. Polar Biology 24, 299–302.CrossRefGoogle Scholar
Stavenga, D.G., Foletti, S., Palasantzas, G. and Arikawa, K. (2006) Light on the moth-eye corneal nipple array of butterflies. Proceedings of the Royal Society B 273, 661–667.CrossRefGoogle ScholarPubMed
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