Sciency Thoughts: Goby

Showing posts with label Goby. Show all posts

Sunday, 28 August 2016

Periophthalmus pusing: A new species of Mudskipper from the Lesser Sunda Islands,

Mudskippers, Periophthalmus spp., are highly specialized Goby Fish, Gobiidae, are highly specialized amphibious Fish found across the tropical and sub-tropical Indo-Pacific and Eastern Atlantic Oceans. The Fish have eyes high on their heads, and modified pectoral girdles which enable them to move about on land, and are often seen foraging on mudflats and in Mangrove forests.

In a paper published in the Raffles Bulletin of Zoology on 25 August 2016, Zeehan Jaafar of the Division of Fishes at the National Museum of Natural History and the Department of Biological Sciences at the National University of Singapore, Gianluca Polgar of the Environmental and Life Sciences Programme at the Universiti Brunei Darussalam, and Yuliadi Zamroni of the Biology Study Programme at Mataram University, describe a new species of Mudskipper from Palau Sumba (Sumba Island) in the Lesser Sundas.

The new species is named Periophthalmus pusing, which derives from the local name for the species 'Ikan Pusing' ot 'Dizzy Fish'; the local people claim that eating the Mudskippers causes headaches and giddyness. The Fish were originally mistaken for members of another species, the widespread Periophthalmus gracilis, which they resemble very closely in size, morphology, colouration and markings, but careful examination revealed that the two species differ in the structure of their fins. As such Periophthalmus pusing is considered to be a cryptic species (cryptic species are species that closely resemble other species, and cannot be separated by simple, non-invasive examination); at the current time the species is known only from a single location, the Kawangu Mangrove Forest on Sumba Island, but it is quite possible that other known populations of Periophthalmus gracilis are in fact members of the new species.

Live specimen of Periophthalmus pusing, approximately 35 mm SL, collected in Sumba Island, Indonesia. Jaafar et al. (2016).

Wednesday, 19 June 2013

A new species of Goby from the southwest Indian Ocean.

Gobies are small, elongate Fish related to Perches. They are a highly successful group with other 2000 species and are found across the globe. There are both marine and freshwater Gobies, as well as one group, the Mudskippers, that can survive out of water for extended periods of time. The smallest known Vertebrates are species of Goby under 1 cm in length as adults, though there are several contenders for the official title of smallest species.

In a paper published in the journal Zootaxa on 19 March 2013, Naomi Delventhal and Randall Mooi of the Department of Biological Sciences at the University of Manitoba describe a new species of Goby from the southwest Indian Ocean, based upon three specimens collected in the Comoros Islands in 1988 and one specimen collected from off the coast of South Africa in 1998.

The species is placed in the genus Callogobius, which contains about 40 shallow marine species from around the fringes of the Indian Ocean, and given the specific name winterbottomi, in honour of Rick Winterbottom of the Royal Ontario Museum, who collected the Comoron specimens.

Callogobius winterbottomi is a small Goby, the largest specimen being 37.7 mm in length. It is distinguished from other species of the same genus by the pattern of sensory papillae (external tastebuds) on its head.

Sensory papillae pattern in Callogobius winterbottomi. (a) Lateral view. Arrow indicates anterior extent of gill opening. (b) Dorsal view. Scale bar is 2 mm. Delventhal & Mooi (2013).

The three specimens of Callogobius winterbottomi from the Comoros, shown to scale. Scale bar is 5 mm. Delventhal & Mooi (2013).

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Friday, 13 July 2012

New species of Whitecap Shrimp Goby from the Western Pacific.

A number of groups of Goby have independently developed symbiotic relationships with other species, one notable example of this being the relationship between some Gobies and burrowing Shrimps. Such Gobies live in the burrows of blind, or at least poorly sighted Shrimps and act as lookouts for predators when both burrow residents are out foraging. For this reason they are sometimes called Watchmen Gobies.

One such species is the Whitecap Shrimp Goby, Lotilia graciliosa, which was first described in 1960 by Wolfgang Klausewitz in the Red Sea. Subsequently a group of Japanese scientists reported the presence of a second population of the Fish in the Western Pacific in 1981. Whitecap Shrimp Gobies are sometimes sold as aquarium fish, though they seldom do well as their symbiotic Shrimps tend not to survive in captivity, and the fish do not usually last long without them.

In a paper published in the journal Zootaxa on 2 July 2012, Koichi Shibukawa of the Nagao Natural Environment Foundation, Toshiyuki Suzuki of Kawanishi-midoridai Senior High School and Hiroshi Senou of the Kanagawa Prefectural Museum of Natural History describe a new study of the Whitecap Shrimp Goby, in which they conclude the two populations are in fact different species.

Shibukawa et al. carried out a study of the fine structure of the sensory canals (loosely nostrils, though in Fish these structures are only used for chemoreception, or 'smell', and not for respiration) and pores of the head, and came to the conclusion these were quite different in the two populations. For this reason they describe the Western Pacific Whitecap Shrimp Goby as a separate species, Lotilia klausewitzi, named in honour of Wolfgang Klausewitz.

The Western Pacific Whitecap Shrimp Goby, Lotilia klausewitzi, Iriomote-jima Island, Yaeyama Group of Ryukyu Islands, Japan (photographed by K. Yano). Shibukawa et al. (2012).