Coal whitefish [1] ( lat. Channichthys panticapaei ) is a marine autochthonous subantarctic bottom or bottom fish from the family of white-blooded , or white-breasted (Channichthyidae) perciform order. The Latin name of the species “ panticapaei ” was given in 1995 by the Ukrainian ichthyologist G. A. Shandikov [2] , who first described this species as new to science and named it in honor of the city of Kerch ( Crimea ), where the YugNIRO research institute is located [3 ] engaged in research in the Antarctic. In the expedition of YugNIRO on the research vessel Professor Mesyatsev to the Kerguelen Islands in 1990, this new species of white-headed fish was found. The scientific name of the species comes from the Latinized Greek name Panticapaeum ( Παντικάπαιον ) - the ancient name of modern Kerch . The Russian name C. panticapaei (like the English "charcoal icefish") is due to the very dark, almost black (coal) or dark brown lifetime of the fish [2] [4] .
| Coal Squirrel |
Coal whitefish Channichthys panticapaei , holotype , male |
| Scientific classification |
|---|
| No rank : | Bilateral symmetrical |
| Family: | White-blooded fish |
| Gender: | Rhinoceros squirrels |
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| International scientific name |
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Channichthys panticapaei Shandikov, 1995 |
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Kerguelen Islands - Typical Coal Whitebird Habitat
C. panticapaei is a medium-sized coastal fish with a total length of not more than 40 cm. It is endemic to the waters of the Indian Ocean , washing the islands of the Kerguelen archipelago and, possibly, the islands of Heard and McDonald's , as well as a series of underwater uplifts - guyots (cans) between them located in the Indian Ocean subantarctic sector in the area of the underwater ridge Kerguelen . In addition to C. panticapaei, the genus of rhinoceros whitefish ( Channichthys ) includes another 8 species of albino fish endemic for Kerguelen [5] .
According to the scheme of zoogeographic zoning for bottom fish proposed by A. P. Andriyashev and A. V. Neyelov [6] [7] , the above region is located within the boundaries of the zoogeographic district of Kerguelen-Hurd, Indo-Oceanic province of the Antarctic region.
Like other rhinoceros whitefish , C. panticapaei has a well-developed rostral spike (“horn”) in the anterior part of the snout. For it, as for all other white-headed fish, the absence of scales on the body (except for the lateral lines) and the unique phenomenon among all vertebrates, characteristic of only 25 species of fish of this family, are also characteristic — the presence of “white” blood, which is a slightly yellowish plasma devoid of red blood cells and hemoglobin. This phenomenon is explained by the adaptation of the ancestral forms of white-blood fish to the harsh conditions of the Antarctic and, accordingly, a decrease in the water temperature in the Southern Ocean to negative values close to the freezing point (–1.9 ° C) [2] [4] .
Coal whitefish can be found as by-catch in the fishery in the Kerguelen Islands for the pike-shaped whitefish Chamsocephalus gunnari Lönnberg, 1905, better known under the commercial name “ icefish ”.
Head of
C. panticapaei , top and side view
It differs from other species of the genus Channichthys in the following set of characters. In the first dorsal fin, there are 6-8 flexible spiny rays, of which the 2nd and 3rd are largest; in the second dorsal fin 32–34 rays; in the anal fin 30–32 rays; in the pectoral fin 20-22 rays; in the dorsal (upper) lateral line of 64–83 tubular bone segment (scales), in the back of the medial (median) lateral line of 7–23 tubular bone segment (scales), in the front part - 4–27 perforated rounded bone plaques; in the lower part of the branchial arch there are 2 rows of stamens: the total number of stamens is 18–31, of which 11–17 are in the outer row and 6–15 are in the inner; the vertebrae are 55–57, of which 23–24 are the trunk and 31–33 are the tail [2] [4] [5] .
The first dorsal fin is high, its height is 3.2–5.1 times the standard length of the fish, more or less triangular in shape (not trapezoidal), with a very low fin fold, reaching a height of no more than 3/4 of the length of the largest spines . The first and second dorsal fins are separated by a wide inter-dorsal gap. The interorbital space is very wide (19-23% of the length of the head), flat, usually larger than the diameter of the orbit. The posterior edge of the jawbone extends backward to the vertical through the middle of the orbit. Granulation (tuberculation) on the body is very strong, small sharp bone bones give the fish a strong roughness. Granulation is especially pronounced on the head, especially the frontal bones, in the back of the jawbone and in the front of the dentary, on the first four to five spiny rays of the first dorsal fin, on the rays of the gill membrane and on the bone plates of the lateral lines. In the anterior section of the medial lateral line there are very dense, rounded perforated bone plaques. In the lower part of the first branchial arch, well-developed stamens densely covered with bone teeth are always arranged in 2 rows.
The general coloration of the body of living fish varies from dark gray with a characteristic marble spot, to almost black. The lower body and narrow areas along the base of the anal fin are usually lighter, and in immature fish almost white, with little pigmentation. The spiny rays and the fin fold of the first dorsal fin are dark, almost black. The rays of the second dorsal, pectoral, and caudal fins are dark brown; the fin folds are light. Anal fin light, with dark spots in the distal part of the rays. Abdominal fins dark above, slightly lighter towards the edges; sometimes there are light spots and transverse black stripes on the fins.
The well-known range of the species covers the coastal sea waters surrounding the islands of Kerguelen ( endemic ). A relatively shallow species recorded in 4 bottom trawls in 1987 and 1990 northeast of Kerguelen Island at depths of 112–154 m [2] [4] .
Belongs to the group of medium-sized species of the genus Channichthys . The largest females reach 402 mm of total length and 361 mm of standard length. The sizes of the largest males do not exceed 394 mm of the total length and 354 mm of the standard length [2] [4] .
Leads a bottom or bottom lifestyle. Macrozooplanktophagus, apparently feeding on the surface of the soil and in the bottom layers of water. Amphipods ( Themisto gaudishaudi ) and small euphausiids ( Thysanoessa macrura ) were found in the stomachs of fish. Like other rhinoceros feeding on zooplankton in coal albino, the gill stamens are numerous and are arranged in two rows on the lower part of the first gill arch [2] [4] .
Puberty first occurs with a total length of about 30 cm (27 cm of standard length). Spawning occurs in the winter period of the southern hemisphere - in June – July. In the second half of July 1990, almost all fish already spawned. In single males, gonads were found in a fluid state (V stage of maturity). 2 females in the ovaries marked unspent, without traces of resorption of eggs. In the largest female with a total length of 402 mm, the gonads were in the pre-spawning state (IV-V stage of maturity).
The species Channichthys normani Balushkin, 1996 [8] is regarded as invalid [1] and is a junior synonym for Channichthys panticapaei .
