Badis chittagongis

Badis chittagongis
Systematics
	Spinefish (Acanthopterygii)
	Perch relatives (Percomorphaceae)
Order :	Climbing fish species (Anabantiformes)
Family :	Blue bass (badidae)
Genre :	Badis
Type :	Badis chittagongis
Scientific name
	Badis chittagongis
	Kullander & Britz , 2002

Badis chittagongis is a bluefish the genus badis . It was only described in 2002and lives in creeks in the district of Cox's Bazar in the Chittagong division , in the extreme southeast of Bangladesh .

description

The body of Badis chittagongis is elongated with a standard length of 22.5 to 35.5 millimeters and strongly flattened on the sides. The head takes up about three tenths of the standard length. There is great variability in drawing and physique that may be related to sexual dimorphism . In the specimens whose sex has been determined, females are smaller and have a relatively taller body. The eyes of both sexes stand far forward and are roughly in line with the longitudinal axis of the body or a little lower. The lower jaw protrudes only slightly. Nothing is known about the live color. The types have a pale light brown to yellowish base color with a conspicuous dark brown shoulder spot and ten black or dark brown horizontal stripes on the sides up to the caudal stalk. The horizontal stripes are formed by a dark coloring of the scales, which have a different intensity and give an irregular impression.

The lateral scales are pronounced ctenoid scales , while there are cycloid scales on the head. In the middle longitudinal row there are 26 to 27 scales, in the transverse row 8.5 and around the tail fin stalk 16 to 19 scales. The dorsal and anal fins are long with rounded tips. They reach in length to about a quarter or a third of the caudal fin, while the fins of larger specimens are relatively longer. The caudal fin is rounded. The pectoral fins are rounded, they reach about two thirds of the way from their base to the anal fin. The pelvic fins are elongated but not pointed. Their ends only reach the anus in large males, but they usually stay shorter.

Badis chittagongis can hardly be distinguished morphologically from Badis pallidus . The individuals have an overall darker body color with only minor deviations in drawing and scale formula. The type is also similar to the bluefish ( Badis badis ) Badis ferrarisi , Badis kanabos , Badis Khwae , Badis ruber and Badis siamensis , with which it has its dark humeral spot together. The species differs from Badis khwae , Badis ruber and Badis siamensis by the lack of a dark spot in the upper area of the caudal fin stalk . Compared to the blue perch , Badis chittagongis has a flatter build, a larger eye relief relative to the standard length, more scales in the central longitudinal row and 13 instead of 12 pectoral fin rays. Compared to Badis kanabos , it has a shorter eye relief relative to the standard length, 20 instead of 16 to 17 scales around the caudal stalk, a larger number of scales in the middle longitudinal row and 13 instead of 12 pectoral fin rays. From Badis ferrisi differs Badis chittagongis by the absence of distal extrascapularen bones.

distribution

Badis chittagongis has so far only been detected in creeks on the mainland of the Chittagong division , which flow directly into the Bay of Bengal in the Cox's Bazar district south of the Teknaf Game Reserve or are located on the island of Maheshkhali . The type location is a small flow in the city Lama ( 21 ° 27 '36 " N , 92 ° 7' 12" O ) in the catchment area of the Matamuhuri . It is located in the Bandarban District , which is south of the Chittagong Hill Tracts in southeastern Bangladesh. The IUCN stated the area of the distribution area in 2015 at around 4,100 square kilometers, the actually populated area at around 18 square kilometers. However, this information also included the distribution area of the Badis pallidus species, which was only described in 2019 on the basis of molecular genetic studies , whose distribution is limited to the catchment area of the Karnaphuli . More detailed descriptions of the sites are not available. The missing evidence from western Myanmar can be traced back to the incomplete research into the waters of this region. 21.46 92.12

Hazard and protection

The small known range would justify the classification of Badis chittagongis in one of the hazard categories of the IUCN. However, in view of the lack of information about possible further localities and the frequency of the species at the known localities, a classification was dispensed with for the Red List of Endangered Species of Bangladesh in 2015 and reference was made to the insufficient data basis (Category DD - Data Deficient ).

Systematics and taxonomy

Badis chittagongis is one of around 25 species of the Badis Bleeker genus, dating from 1854, almost all of which were not described until the 21st century. The first descriptions of ten of these species, including Badis chittagongis , were published in 2002 by the Swedish ichthyologist Sven O. Kullander from Naturhistoriska riksmuseet in Stockholm and Ralf Britz from the National Museum of Natural History in Washington, DC as part of their revision of the genus Badis . Kullander and Britz presented Badis chittagongis due to morphological features and because of their adjacent areas of distribution together with the bluefish, Badis ferrarisi and Badis kanabos in the Badis badis group.

The holotype is an adult male captured in June 1996. It is in the collection of the California Academy of Sciences (CAS) in San Francisco with 31 paratypes from other locations in the Chittagong division . The specific epithet chittagongis is derived from the location of the type site in the Chittagong Hills and thus indirectly from the name of the city of Chittagong .

Web links

Badis chittagongis on Fishbase.org (English)

Badis chittagongis onthe IUCN Red List of Threatened Species .

Individual evidence

↑ ^a ^b ^c ^d ^e ^f Sven O. Kullander and Ralf Britz: Revision of the family Badidae (Teleostei: Perciformes), with a description of a new genus and ten new species . In: Ichthyological Exploration of Freshwaters 2002, Volume 13, No. 4, pp. 295-372, here pp. 314-316, ISSN 0936-9902 .
↑ ^a ^b ^c Sven O. Kullander et al .: Chameleonfishes in Bangladesh: hipshot taxonomy, sibling species, elusive species, and limits of species delimitation (Teleostei: Badidae) . In: Zootaxa 2019, Volume 4586, No. 2, doi : 10.11646 / zootaxa.4586.2.7 .
↑ ^a ^b Balaram Mahalder and Md. Golam Mustafa: Badis chittagongis . In: IUCN Bangladesh (ed.): Red List of Bangladesh. Volume 5. Freshwater Fishes . International Union for Conservation of Nature (IUCN), Bangladesh Country Office, Dhaka 2015, p. 299.
^ Sven O. Kullander and Ralf Britz: Revision of the family Badidae , pp. 370–371.

[Kullander-1] ↑ ^a ^b ^c ^d ^e ^f Sven O. Kullander and Ralf Britz: Revision of the family Badidae (Teleostei: Perciformes), with a description of a new genus and ten new species . In: Ichthyological Exploration of Freshwaters 2002, Volume 13, No. 4, pp. 295-372, here pp. 314-316, ISSN 0936-9902 .

[Kullander_2019-2] Sven O. Kullander et al .: Chameleonfishes in Bangladesh: hipshot taxonomy, sibling species, elusive species, and limits of species delimitation (Teleostei: Badidae) . In: Zootaxa 2019, Volume 4586, No. 2, doi : 10.11646 / zootaxa.4586.2.7 .

[RL_BD_2014-3] Balaram Mahalder and Md. Golam Mustafa: Badis chittagongis . In: IUCN Bangladesh (ed.): Red List of Bangladesh. Volume 5. Freshwater Fishes . International Union for Conservation of Nature (IUCN), Bangladesh Country Office, Dhaka 2015, p. 299.

[4] Sven O. Kullander and Ralf Britz: Revision of the family Badidae , pp. 370–371.