Trypauchen vagina (Bloch and Schneider, 1801)

Edward O. Murdy, 2006, A revision of the gobiid fish genus Trypauchen (Gobiidae: Amblyopinae)., Zootaxa 1343, pp. 55-68 : 61-65

Trypauchen vagina (Bloch and Schneider, 1801)

(Figs.1-5, Tables 1-2)

Gobius vagina Bloch and Schneider, 1801 : 73 ( type locality, Tranquebar, India ).

Gobioides ruber Hamilton-Buchanan, 1822 : 38, 365 ( type locality, Ganges River, India ).

Trypauchen vagina : Valenciennes in Cuvier & Valenciennes, 1837: 152 ( new combination).

Material examined. (Total of 33 specimens, 69.0-170.0 mm SL). Kuwait: BPBM 33186, 2:80.3-94.2, 29°N, 48°25' E, 15-20 m, collected by James M. Bishop aboard the R/V Bahith, 20 Aug 1985 . India: AMS I.27225-001, 1:115.3, 19 Mar 1968 . Bombay (Mumbai): AMS I.43479-001 (cleared & stained), 1:77.0; Bombay Harbor, collected by Ron Baird, 1967 ; USNM 337796, 1:122.1, Bombay Harbor, collected by Ron Baird, 1967 ; USNM 342640 (cleared & stained), 1:104.4, Bombay Harbor, collected by Ron Baird, 1967 . Cochin: BPBM 27544, 5:104.5-162.1, obtained from local fish catch (trawled) near Cochin landing dock, collected by John E. Randall, 1 Feb 1980 . Tranquebar: ZMB 2127, holotype of Gobius vagina Bloch and Schneider , 154.0. Calcutta: AMS B.7988, 1:170.0, 22°30’N, 88°20’E, collected by Francis Day . Myanmar: Kuala Bernam, Bernam River estuary, AMS I.28984-046, 1:114.8, 03°47’N, 100°55’E, collected by D.G. Stead, 23 Feb 1922 . Thailand: Songkhla Lake: UMMZ 233638, 2:136.0-143.6, Dec 1964 . Samut Prakan, mouth of Chao Phraya River, USNM 103351, 1:137.9 . Chanthaburi estuary: USNM 103350, 1:144.7 . Bangpakong River: USNM 109695, 1:88.3, collected by H.M. Smith, 27 June 1933 . Vietnam: Mekong Drainage, mouth of Song Cua Dai, UMMZ 241627, 5: 69.0-162.0, 10°13’N, 106°15’E, collected by local fishermen for Walter J. Rainboth, April, 1999 . Kien Giang, Mekong Delta: UMMZ 238875, 1:147.8, 10°23’N, 104°29’E, purchased at Ha Tien market by Walter J. Rainboth, 28 Mar 1999 . Vung Tai: USNM 304795, 1:155.2, 10°21’N, 107°15’E, purchased at fish market by D.P. DeSylva, 19 Jan 1973 . Philippines: East coast of Luzon: USNM 151241, 1:109.7 . China: Guangdong Sheng, Shantou: AMS I.38176-001, 1:131.1, 5 Mar 1954 . Foochow: USNM 086958, 3:102.0-119.1, collected by A.C. Sowerby, Sept-Nov 1923 . Xiamen: AMS I.28094-016, 2:117.5-141.8, fish market purchase, 13 Oct 1988 .

Description. As for genus except as follows. Total elements in dorsal fin 50-58 (mean = 55.2); total elements in anal fin 43-50 (mean = 46.6); pectoral-fin rays 15-20 (mean = 17.7); anal-fin pterygiophores preceding the first hemal spine 3-4 (mean = 3.9); caudal vertebral count 23-24 (mean = 23.9). The following subset of morphometric measures from Table 2 is useful in describing T. vagina and differentiating T. vagina from T. pelaeos : SL/total length 0.815-0.938 (mean = 0.855); head length/SL 0.161-0.179 (mean = 0.169); predorsal length/SL 0.188-0.218 (mean = 0.202); prepelvic length/SL 0.157-0.175 (mean = 0.165); preanal length/SL 0.308-0.362 (mean = 0.345).

Four to 16 teeth (mean = 7.9) on outer row of upper jaw; 8-13 teeth (mean = 10.6) on outer row of lower jaw.

Longitudinal scale rows 69-98 (mean = 82.4).

Color when fresh. No fresh specimens were available. A photograph of a freshly dead T. vagina from Cochin, India (photographed by John E. Randall) is reproduced as Fig. 3 and a specimen from Vietnam (photographed by Walter Rainboth) is reproduced as Fig. 4. The specimen from India (BPBM 27544, Fig. 3) is reddish pink on the head and body, but not uniformly. The cheek is bright red as is the dorsum anteriorly. The prepeduncular area is similarly bright red. Ventral to the pectoral-fin base is dusky. All fins are translucent. The specimen from Vietnam (UMMZ 238875, Fig. 4) is almost uniformly pinkish except for a reddish band anterior to the operculum and a reddish blotch dorsal to the pectoral fin. All fins are translucent.

As described by Hamilton-Buchanan (1822), Gobioides ruber (= Trypauchen vagina ) was a dirty red color. Bleeker (1860) described the body color as rosy red and the fins as transparent with a rosy tinge. According to Day (1878), T. vagina is white with a rosy tinge, much brighter during some seasons than at others with the distal margins of the median fins gray and the caudal, pectoral, and pelvic fins white, or tinged with yellow. Smith (1945) stated that his specimens were pinky white with minute black eyes. The photograph of a presumably freshly dead of T. vagina in Chen and Fang (1999) depicts a mostly blood-red head and body with black-edged fins and a solid black caudal fin. A photograph of T. vagina from Singapore in Larson and Lim (2005) has a reddish-orange body with the anterior part of the head and the caudal peduncular region tannish white with translucent fins.

Color in alcohol. Head and body uniformly tannish brown with translucent fins. Herre (1927) stated that preserved specimens of T. vagina were pinkish brown to gray or bluish brown, the head often paler, the fins yellowish or whitish.

Ecology. Rainboth (1996) reported that in the Cambodian Mekong, T. vagina does not venture far from its burrow and preys on small crustaceans. Chen and Fang (1999) stated that T. vagina inhabits burrows in estuarine and coastal areas including river mouths and is an omnivorous benthic feeder. During storm seasons when salinity fluctuates greatly, T. vagina can be locally abundant in estuaries (Chen and Fang, 1999).

Distribution. Kuwait, east and west coasts of India, Myanmar, Thailand, Singapore (Larson and Lim, 2005), Indonesia, the Philippines, Taiwan (Chen and Fang, 1999), and China. Specimens of this species have not been examined from Singapore or Taiwan. Because T. vagina is found in burrows in silty mud habitats, it is difficult to collect, which may help explain its relative paucity in museum collections.

Remarks. The holotype (ZMB 2127) of Trypauchen vagina Bloch and Schneider (1801) could not be loaned for this study; however, a radiograph was examined. In addition, the notes and drawings of Helen K. Larson, who did examine the holotype, were made available. Based on the original description, H. K. Larson’s notes and drawings, and data gleaned from the radiograph (PF=3-1221, AP=4, total dorsal-fin elements 56, total anal-fin elements 47, vertebrae 10+23), the status of this specimen is not in doubt. (The original description mistakenly lists the number of anal-fin rays as 44.)

As no types are known for Gobioides ruber Hamilton-Buchanan (1822) , the synonymy is based on the original description. As described by Hamilton-Buchanan, the count for the dorsal fin of Gobioides ruber is 55 and the anal-fin ray count is 52; the former is close to the mean for this species (55.2) and the latter is two higher than for any specimen examined. This synonymy was first proposed by Bleeker (1860).