The first finding of the Striped tripletooth goby Tridentiger trigonocephalus (Perciformes, Gobiidae) in the Black Sea (the estuary of the Chernaya River, Sevastopol Bay)

Abstract

In the estuary zone of the Chernaya River, approxi-mately within 400 m from its inflow in the SevastopolBay, on September 4, 2006, a goby was captured andbrought alive to the Institute of Biology of SouthernSeas, identified later as the Striped tripletooth goby Tri-dentiger trigonocephalus. Fishing was made at a per-manent station with a hauled dipnet touching the bot-tom. The aperture of the dipnet is semicircular, 1.0 ×0.5 m in size, mesh size 6.5 mm. The depth of the haulwas 4–5 m, temperature at water surface 20.5°C, andsalinity at 14.96‰. The ground was silt sandy andpartly covered with aquatic vegetation.The species was identified using the key for speciesof the genus Tridentiger composed by Pinchuk (1992)on the basis of publications of Japanese authors (Aki-hito et al., 1984; Akihito and Sakamoto, 1989), compar-ative materials from the collection of the ZoologicalMuseum of Moscow State University (ZMMU), andmorphological data, photographs and drawings of spe-cies of this genus are from various publications (Wu,1931; Wang and Wang, 1935; Berg, 1949; Takagi,1963; Lindberg and Krasyukova, 1975; Kawanabe andMizuno, 1955; Kim and Park, 2002; Shimizu et al.,2006) and Internet sites: DFG WA, 2005; The Fishes ofPrimor’e, 2005; FishBase (Froese and Pauly, 2007);USGS (Nico and Fuller, 2007); Species blog, 2007;Japanese Freshwater Fishes, 2007.As the occurrence of this species in the basin of theBlack Sea is unexpected, we include in the present pub-lication a detailed description of the captured specimenwith the data of morphometric analysis made accordingto standard methods (Smirnov, 1986; Miller, 2003) anda description of morphology and coloration used in thediagnoses of species of this genus. At present this goby(female) is deposited at the ZMMU (P-21675).D VI, I 11; A I 11; P 19; V 10; number of transverserows of scales 51. Absolute length (TL) 44.2 mm, bodylength from snout to base of middle rays of caudal fin(SL) 36.5 mm. Teeth in outer row on upper and lowerjaws tricuspid; forehead is narrow and convex, its widthsmaller than horizontal diameter of eye and is 5.1 timesin head length; pores of supraorbital canals large, theirdiameter is similar in size to diameter of posterior nos-tril; supraorbital canals wide, connivent, smallest dis-tance between canal of left and right sides of head (inthe middle of forehead) noticeably smaller than half ofhorizontal eye diameter; rays of first dorsal fin notthreadlike, elongated; uppermost ray of pectoral fin freeof membrane (ends of ray broken on both sides); scaleson occiput and belly present.Morphometric characters, in % SL: greatest bodydepth at beginning of dorsal fin 21.3, depth of caudalpeduncle 12.8, length of caudal peduncle 21.9, antedor-sal distance 38.1, postdorsal distance 51.8, anteventraldistance 35.9, anteanal distance 60.3, pectoventral dis-tance 16.2, ventroanal distance 26.3, pectoral fin length21.6, ventral fin length 18.4, depth of first dorsal fin14.3, length of base of first dorsal fin 19.2, depth of sec-ond dorsal fin 13.2, length of base of second dorsal fin26.0, distance between dorsal fins 2.5, depth of anal fin13.7, length of base of anal fin 20.0, length of caudal fin20.6, head length (c) 28.0. In % c are the following:greatest depth of head 68.6, greatest width of head 78.4,snout length 32.4, length of upper jaw 29.4, length oflower jaw 31.4, horizontal eye diameter 21.6, postor-bital distance 55.9, distance between eye and angle ofmouth 21.6, cheek depth 38.2, distance between anglesof mouth 34.3, width of forehead 19.4.The intravital coloration is light gray, the body isalmost transparent, and there are two contrasting darkbands along the whole body: the upper band beginsover the eye and extends along the dorsal part at thebase of dorsal fins up to the beginning of the upper raysof the caudal fin, the lower band extends from thebeginning of the snout, through the eye, bases of pecto-ral fins, and along the median line of the body up to the