Laubuka tenella
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Laubuka tenella from where the type was found , photographed alive immediately after the catch |
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| Laubuka tenella | ||||||||||||
| Kullander , Rahman , Norén & Mollah , 2018 |
Laubuka tenella is a bear of the genus Laubuka . It was in 2018 described and lives in streams in Cox's Bazar District in southeastern Bangladesh and in the catchment area of Thandwe in Rakhine State of Myanmar .
description
Laubuka tenella is a small species of the genus Laubuka with a standard adult length of up to 47.5 millimeters . The body is elongated and heavily compressed on the sides. There are small pits with neuromasts above the eyes and on the tip of the snout , there are no barbels or tubercles. The snout is shorter than the diameter of an eye, it looks triangular when viewed from the side, rounded when viewed from above and has a terminal mouth.
The basic color of specimens preserved in formalin is a pale yellowish white, the back is colored pale brown with a reticulate pattern. On the side there is a dark spot immediately behind the gill cover. On the back third of the body there are dark side stripes. They go forward in sequences of six to eleven short vertical strips that do not reach the belly. The lively color is a silvery back with green and steel-blue lateral longitudinal stripes, the chest and belly are white.
In the lateral row there are 29 to 32 scales, in the transverse row 9½ and around the caudal stalk 12 scales.
The attachment of the dorsal fin is about two thirds of the standard length and immediately behind the attachment of the anal fin . The pectoral fins are long and sickle-shaped, they do not reach the anus. The pelvic fins are forked to about half their length and start a little in front of the center of the body.
- Fin formula
Dorsal II / 8½, anal III / 16½ – 20½, ventral I / 5–6, pectoral I / 10–12.
Laubuka tenella can be distinguished from all other species of the genus Laubuka , with the exception of Laubuka insularis and Laubuka lankensis , by their pattern . It differs from Laubuka insularis in the fewer number of scales on the side line and the shorter ventral fins, and from Laubuka lankensis also in the fewer number of scales on the side line.
distribution
The type of location is the lower reaches of the Domdomia ( 20 ° 55 '24 " N , 92 ° 15' 47" O ), just before its opening in the Naf . It is located about ten kilometers north of the city of Teknaf and 70 kilometers south of Cox's Bazar in the district of Cox's Bazar , in the extreme southeast of Bangladesh . Another location in Bangladesh is the stream Majerchora ( 21 ° 23 '45 " N , 92 ° 0' 16" O ), a ten kilometers south of Cox's Bazaar situated inflow of Bakkhali . In Myanmar , the species was found in the Nan Chaung stream ( 18 ° 27 ′ 8 ″ N , 94 ° 20 ′ 55 ″ E ), a tributary of the Thandwe on the western slope of the Arakan-Joma Mountains in the Rakhine state . What the three sites have in common is that they are west of the Arakan-Joma Mountains and drain into the Bay of Bengal . It is unclear whether the three sites mark a continuous distribution area or indicate fragmented populations isolated from one another.
Laubuka tenella lives in rapidly flowing brooks with a stony, sandy or loamy bottom that are only a few meters wide and a few decimeters deep in the dry season and can swell strongly during the monsoons, but also in residual waters of almost dried-out rivers. It is associated with Anguilla sp. ( Anguillidae ), Aplocheilus panchax ( Aplocheilidae ), Megalops cyprinoides ( Megalopidae ), Acentrogobius caninus ( Gobiidae ), Eleotris melanosoma ( Eleotridae ), Dermogenys burmanica ( Zenarchopteridae ), Oryzias sp. ( Adrianichthyidae ), Glossogobius giuris (Gobiidae), Channa gachua and Channa punctata ( Channidae ), Danio aesculapii and other Danio sp. , Devario anomalus , Devario coxi , Esomus danrica , Pethia ticto , Puntius chola , Rasbora rasbora ( Cyprinidae ) and Lepidocephalichthys berdmorei ( Cobitidae ).
Systematics and taxonomy
Laubuka tenella is one of more than a dozen species of the genus Laubuka Bleeker , 1859, which, together with Danio , Devario , Microrasbora and several other genera, forms the subfamily Danioninae in the family Bärblinge (Danionidae). The system of the genus is not up to date ; the last revision was made in 1958 on the basis of a species concept that is now outdated. From the genus Laubuka next are Laubuka tenella only two species in Bangladesh demonstrated: from Laubuka laubuca there are younger finds, in pet shops in Dhaka were offered as local catches. Laubuka brahmaputraensis was described in 2012 from specimens that were caught by a local fish catcher in 1995. Only the Brahmaputra in Bangladesh could be given as a type location . The diagnosis was only made according to the specialist literature, without direct comparison with collection copies. L. brahmaputraensis is possibly a synonym of L. laubuca .
The first description of Laubuka tenella was made in 2018 by a group of ichthyologists to the Swede Sven O. Kullander . The basis were fish of the genus Laubuka , which were caught in small streams at Cox's Bazar and Teknaf in 2015 and which differed significantly from Laubuka laubuca , but could not be distinguished morphologically from specimens from a stream in Myanmar. The holotype is an adult specimen of 42.1 millimeters standard length captured in May 2015. It is in the collection of the University of Dhaka . 47 paratypes are kept there and in the collections of the Naturhistoriska riksmuseet in Stockholm and the Natural History Museum in London. The species name tenellus is a Latin adjective meaning fine or delicate and refers to the small size and appearance of freshly caught fish.
Web links
- Laubuka tenella on Fishbase.org (English)
Individual evidence
- ↑ a b c d e f Sven O. Kullander et al .: Laubuka tenella, a new species of cyprinid fish from southeastern Bangladesh and southwestern Myanmar (Teleostei, Cyprinidae, Danioninae) . In: ZooKeys 2018, Volume 742, pp. 105-126, doi: 10.3897 / zookeys.742.22510 .
- ^ Maurice Kottelat: The Fishes of the Inland Waters of Southeast Asia: A Catalog and Core Bibliography of the Fishes Known to Occur in Freshwaters, Mangroves and Estuaries . In: The Raffles Bulletin of Southeast Asian Zoology, Supplement 2013, Volume 27, pp. 1-663, digitized .
- ↑ Sitthi Kulabtong, Siriwan Suksri and Chirachai Nonpayom: A new species of genus Laubuca Bleeker, 1860 cyprinid fish from Bangladesh (Cypriniformes, Cyprinidae) . In: Biodiversity Journal 2012, Volume 3, pp. 93–95, digitized .