Mudskipper

From Wikipedia, the free encyclopedia

iMudskippers

Periophthalmus modestus
SUMA Aqualife Park (Japan)

Scientific classification

Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Perciformes
Family:	Gobiidae
Subfamily:	Oxudercinae

Genera

Apocryptes
Apocryptodon
Boleophthalmus
Oxuderces
Parapocryptes
Periophthalmodon
Periophthalmus
Pseudapocryptes
Scartelaos
Zappa (genus)

Mudskippers are members of the subfamily Oxudercinae (tribe: Periophthalmini<ref name="murdy1989">Murdy, E. O. (1989). "A Taxonomic Revision and Cladistic Analysis of the Oxudercine Gobies (Gobiidae: Oxudercinae)". Records of the Australian Museum Suppl. N°11: 1–93.</ref>), within the family Gobiidae (Gobies). While most marine fish that live in intertidal habitats, survive the retreat of the tide by hiding under wet seaweed or by using tide pools, mudskippers are uniquely adapted to a completely amphibious lifestyle.<ref name="graham1997"> (1997) Graham, J. B. (ed.): Air–breathing Fishes. Evolution, Diversity and Adaptation. San Diego California: Academic Press.</ref> Mudskippers are found only in tropical and subtropical regions, having a geographical distribution that includes all the Indo-Pacific and the Atlantic coast of Africa. Mudskippers are quite active when out of water, feeding and interacting with one another, for example to defend their territories.

Compared with fully aquatic gobies, these fish present a range of peculiar behavioural and physiological adaptations to an amphibious lifestyle. These include:

Anatomical and behavioural adaptations that allow them to move effectively on land as well as in the water.<ref>Harris, V.A. (1961). "On the locomotion of the mudskipper Periophthalmus koelreuteri (Pallas): Gobiidae". Proceedings of the Zoological Society of London 134: 107–135.</ref>

The ability to breathe through their skin and the lining of their mouth (the mucosa) and throat (the pharynx). This is only possible when the mudskipper is wet, limiting mudskippers to humid habitats and requiring that they keep themselves moist. This mode of breathing, similar to that employed by amphibians, is known as cutaneous air breathing.<ref name="graham1997"> </ref>

Digging of deep burrows in soft sediments that allow the fish to thermoregulate;<ref>Tytler P. & Vaughan T. (1983). "Thermal Ecology of the Mudskippers Periophthalmus koelreuteri (Pallas) and Boleophthalmus boddaerti (Pallas), of Kuwait Bay". Journal of Fish Biology 23 (3): 327–337.</ref> avoid marine predators during the high tide when the fish and burrow are submerged;<ref>Sasekumar, A.; Chong, V.C.; Lim, K.H. & Singh, H.R. (1994). Sudara, S.; Wilkinson, C.R.; Chou, L.M. (eds) "The Fish Community of Matang Mangrove Waters, Malaysia". Proceedings, Third ASEAN-Australia Symposium on Living Coastal Resources. Research papers, Vol. 2: 457-464, Bangkok, Thailand: Chulalonghorn University.</ref> and for laying their eggs.<ref>Brillet, C. (1969). "Etude du comportement constructeur des poissons amphibies Periophthalmidae". Terre et la Vie 23 (4): 496–520.</ref>

Image:Periophthalmus gracilis.jpg

Even when their burrow is submerged, mudskippers maintain an air pocket inside it, which allows them to breathe in conditions of very low oxygen concentration.<ref> Ishimatsu A., Hishida Y., Takita T., Kanda T., Oikawa S., Takeda T. & Khoo K.H. (1998). "Mudskipper Store Air in Their Burrows". Nature 391: 237–238. </ref><ref> Ishimatsu A., Takeda T., Kanda T., Oikawa S. & Khoo K.H. (2000). "Burrow environment of mudskippers in Malaysia". Journal of Bioscience 11 (1,2): 17–28. </ref><ref> Lee H.J., Martinez C.A., Hertzberg K.J., Hamilton A.L. & Graham J.B. (2005). "Burrow air phase maintenance and respiration by the mudskipper Scartelaos histophorus (Gobiidae: Oxudercinae)". The Journal of Experimental Biology 208: 169–177.</ref>

The genus Periophthalmus is by far the most diverse and widespread genus of mudskipper. Seventeen species have been currently described.<ref>Larson H.K. & Takita T. (2005). "Two new species of Periophthalmus (Teleostei: Gobiidae: Oxudercinae) from northern Australia, and a re-diagnosis of Periophthalmus novaeguineaensis". The Beagle, Records of the Museums and Art Galleries of the Northern Territory 20: 175–185.</ref> Periophthalmus argentilineatus is one of the most widespread and well known mudskippers. This species can be found in mangrove ecosystems and mudflats of East Africa and Madagascar east through South East Asia to Northern Australia, Southeast China and Southern Japan, up to Samoa and Tonga Islands.<ref name="murdy1989"> </ref> It grows to a length of about 6 in (15 cm) and is a carnivorous opportunist feeder. It feeds on small prey such as small crabs and other arthropods.<ref>Milward, N. E. (1974). Studies on the taxonomy, ecology and physiology of Queensland mudskippers, unpubl. Ph D. dissertation, Univ. Of Queensland, Brisbane, Australia.</ref> Another species, Periophthalmus barbarus, is the only oxudercine goby that inhabits the coastal areas of Western Africa (Murdy, 1989). Both these mudskippers are widely traded as aquarium fish.