Tag Archives: goby

Schismatogobius risdawatiae

11. October 2018

The dragonet gobies (Schismatogobius) are small species of freshwater gobies, that reach between 3 and 5 cm length. They live in small rivulets near the coast but above the tide on sandy bottoms. Here they burry themselves very fast if necessary. The larvae devolop – as far as this known – in the sea. The ability to change coloration is phenomenal in these gobies. The genus Schismatogobius has been established in 1912, 10 species have been accepted since then. Two of them, S. ampluvinculus and S. roxasi, we have introduced to you already (see http://www.aquariumglaser.de/en/?s=schismatogobius).

The year 2017 sees an explosion of newly decribed species in Schismatogobius. First, in a revision of the species occuring from Papua-New Guinea to Samoa, 7 new species have been described, shortly later, in a revision of the species from Indondesia, 4 new species.

We have imported this week Schismatogobius from Indonesia. All the species from Indonesia look very similar to each other and occur in direct neighbourhood; this makes the determination a difficult thing. The scientific deliminations of the species base on DNA-analyses and characters not visible in live specimens. We deny killing specimens for determination purposes. But we are pretty sure that our new importations belong to the species Schismatogaobius risdawatiae, described in July 2017 from Sumatra, due to the very special coloration of the pectoral fins, which are visible in specimens photographed over white bottom from top. S. risdawatiae is a small species, reaching only 2.5-3 cm length (without the caudal fin). The charming animals are absolutely an enrichment for the aquarium hobby.

For our customers: the fish have code 454842 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Literature: 

Keith, P., C. Lord and H. K. Larson (2017): Review of Schismatogobius (Gobiidae) from Papua New Guinea to Samoa, with description of seven new species. Cybium v. 41 (no. 1): 45-66.

Keith, P., C. Lord, H. Darhuddin, G. Limmon, T. Sukmono, R. Hadiaty and N. Hubert  (2017): Schismatogobius (Gobiidae) from Indonesia, with description of four new species. Cybium v. 41 (no. 2): 195-211.

Sicyopus rubicundus

4. April 2018

We received from Indonesia once more a nice shipment containing pretty Sicyopus gobies. These gobies are – despite the external similarity – not feeding on Aufwuchs and microfilm like Stiphodon and Sicyopterus, but are little predators that feed on quite large food items. These include also very small fish and shrimps up to a length of about 1 cm, although the gobies become only 5-6 cm long and are very slender fish.

In respect of the determination there appeared at lot of trouble. Initially the fish were totally colourless and we thought they would belong to the species Sicyopus zosterophorum (Bleeker 1856); but then many males obtained full coloration and were pretty sure that the fish are S. exillisquamulus Watson & Kottelat 1994 – or at least almost sure. For in the latest scientific literature the species S. exillisquamulus has been considered to be a synonym of Sicyopus auxilimentus Watson & Kottelat 1994.

Finally Laurent Tyty kindly gave us the crucial hint that according to the most current scientific literature (Keith et al., 2015) our fish is actually S. rubicundus Keith, Hadiaty, Busson & Hubert, 2014; S. auxilimentus (besides S. exillisquamulus an additional synonym is, fide Keith et al., S. cebuensis Chen & Shao, 1998) has in contrast to S. rubicundus no orange lips.

Our first importation of S. rubicundus dates back to the year 2006. At that time we termed them Sicyopus sp. Red. The species is distinguished from S. zosterophorum by the lack of a black stripe under the eye, bright orange lips and the lack of clearly visible vertical stripes. Moreover the basic coloration of S. rubicundus is rather orange and in S. zosterophorum red. The females of both species are almost colorless.

Sicyopus are inhabitants of brooks and like clear, clean, and running water, hiding places and sandy bottom. Sicyopus regulary spawn in aquaria, they are cave brooders, but the larvae are very tiny and develop in marine environements. We have not heard so far from a successful rearing of the larvae under hobby conditions.

For our customers: the animls have code 456183 on our stocklist. Please note that we exclusively supply the wholesale trade.

Literature:

Keith, P., C. Lord & K. Maeda (2015): Indo-Pacific Sicydiine gobies. Biodiversity, life traits and conservation. Société Française d’Ichtyologie, Paris. 1-256.

Odonteleotris macrodon

23. March 2018

We obtained from Thailand five specimens of that odd goby which are about 15 cm long. Our first idea was that they would belong to the species Oxyeleotris urophthalmus. The genus Oxyeleotris is repersented by three species in Thailand, two of them with an ocellus in the upper part of the caudal peduncle. Both are very similar to each other externally. Another very similar species from Thailand, also with an Ocellus, is Bostrychus sinensis. All of them attain a length of about 20 cm. Smith (1945) gives the best identification key available so far for the three species. According to him, Bostrychus sinensis has very small scales, about 140 in lateral line and very small teeth that are arranged in bands. Oxyeleotris has canine teeth. O. siamensis has about 90 scales in lateral line (about 40 predorsal scales), a small barbel on both sides of the upper jaw and the snout is unscaled. O. urophthalmus has 70-75 scales in lateral line (about 30 predorsal scales), no barbels and a scaled snout.

Our fish have canine teeth, no barbels, about 75 scales in lateral line and about 20 predorsal scales (these counts were made from photos) and no visible scales on the snout. So the results do not fit for one of the two Oxyeleotris species, although it is pretty difficult to get proper counts of the small scales that are embedded in thick mucus.

We had to start again. We found Odonteleotris macrodon, a species with a very wide distrubution from India to Malaysia and Indonesia. This species also has an ocellus. Although the scale counts do not fit perfectly (this species has usually about 90 scales in lateral line) all other external features do.

So obviously Odonteleotris macrodon also occurs in Thailand, a finding that is not much surprising, but not reported so far in the scientific literature. 

Odonteleotris macrodon is a brackish water species that is also found in pure freshwater. It attains a maximum length of about 30 cm and is a predatory fish. The larvae develop as far as it is known in marine environment.

For our customers: the animals have code 414745 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer

Brachygobius sabanus Thailand

20. March 2017

We received this pretty species of bumblebee goby from Thailand. The determination of bumblebee gobies often proofes to be quite tricky; usually a big questionmark has to be set behind the names. Brachybobius sabanus has been described initially from Borneo (Sabah), our fish have been collected in Thailand. But the illustration accompanying the original description of B. sabanus fits very good for our specimens.

B. sabanus attains a maximum length of about 2.5 cm. The coloration differs a lot individually. The species inhabits pure freshwater habitats. We were very glad to observe a spawning in our facility. But we thought the eggs would suffer from fungus quite fast. When the male was defending the whitish eggs still for days we took a closer look and discovered that the eyes of the offspring were already visible in the eggs. In fact it was the white yolk sack, not fungus that made the eggs look white! Sadly the larvae hatched on weekend in the night when no one was in our fishhouse. But we think an experienced hobbyist should be able to raise Brachygobius sabanus without problems.

For our customers: the fish have code 407252 on our stocklist. Please note that we exclusively supply the wholesale trade.

Text & photos: Frank Schäfer