Fimbriate Gudgeon

Dorsal spines (total): 7; Dorsal soft rays (total): 112; Analspines: 1; Analsoft rays: 9 - 10

Inhabits rivers, creeks, swamps, lakes and ponds. Usually shelters among log debris or undercut banks (Ref. 44894). Occurs in headwaters, often in hilly or mountainous terrain. Found on both rock and mud bottoms.

Oxyeleotris fimbriata (Weber, 1908)

USNM 217288, Fly 75–2, 4: 63.3–77.9 mm.

USNM 217289, Fly 75–4, 5: 11.0–64.7 mm.

USNM 217290, Fly 75–13, 1: 148 mm.

USNM 217291, Fly 75–14, 1: 82.0 mm.

USNM 217292, Fly 75–16, 3: 44.9–61.3 mm.

Oxyeleotris Bleeker, 1874 (type-species Eleotris marmorata Bleeker, 1852, by original designation), comprises a number of riverine and estuarine species in Southeast Asia, the Australian Region, and the tropical western Pacific (Koumans, 1936a; 1953).

Oxyeleotris fimbriata occurs in lacustrine and riverine habitats in the Upper and Middle Fly, where it attains at least 148 mm (Koumans, 1936a: 133, indicates a maximum of 300 mm for this species without indicating locality). Specimens from the Fly have cephalic pores well developed, with 2 nasal, 3 orbital, 4 preopercular, and 4 lateral line canal pores. Head relatively depressed. Horizontal diameter of eye 12.3–16.8 (4: 24.6–61.3 mm). Scales in lateral series 51–74. Total number of fin rays in second dorsal fin 12(2), 13(5), 14(4). Total number of anal fin rays 10(4), 11(7), 12(2). Pectoral fin rays 13(2), 14(5), 15(1), 16(2). Complete vertebral centra 27–29(4). Body usually with 11–16 chevron-shaped marks, vertically oriented, with apex of chevron directed posteriorly. These marks are variable; they may be poorly defined or absent. The chevrons are often better defined on the anterior half of the body than on the posterior half, and the lower limbs of the chevrons are often more distinct than the upper limbs. Comparable marks, present in some other species from New Guinea, are absent in Asian species. Pectoral and caudal fins usually with melanophores forming clusters or round spots arranged in several equally prominent vertical bands; these fin markings, although not always present, may be well developed in specimens as small as 11 mm.

Koumans (1936b) studied 81 specimens, 16–225 mm, from various localities in former Dutch New Guinea, all identified as O. fimbriata, and reported a regular increase in number of scales with growth, from 45–48 in a lateral series in specimens under 40 mm to 71–77 in specimens over 180 mm. Scale counts on my material from the Fly indicate that Koumans’ concept of O. fimbriata probably involved more than one species. Thus my largest sample, Fly 75–4, comprises five specimens of 11, 17, 24, 42, and 65 mm, with respective counts of 63, 69, 68, 68, and 68 scales in a lateral series. The lowest scale counts in my Fly material, 50–61, are in the specimens from Fly 75–2. Although I have identified them as O. fimbriata, they are heavier bodied and differ in coloration from the other samples and may represent another species (possibly O. aruensis Weber, 1911, or O. mertoni Weber, 1911, both of which Koumans treated as synonyms of O. fimbriata). If this lot is discounted, scale counts in my Fly O. fimbriata range from 60–74.

Munro (1964:184, fig. 22) identified specimens of a distinctive Oxyeleotris from Mendi district (central highlands of Papua New Guinea, presumably Purari drainage) as juvenile O. fimbriata. These specimens, 47–78 mm, are described as having no scales on the cheek, gill cover, pectoral fin base, or breast (the figure of a 71-mm specimen indicates the entire abdomen is also scaleless). In all Oxyeleotris I have examined, including the smallest O. fimbriata, all of these areas are fully scaled. The coloration of the Mendi fish, as described and figured by Munro, is also unlike that in any previously described Oxyeleotris.

The fimbriate gudgeon (Oxyeleotris fimbriata) is a species of sleeper goby native to the fresh waters of New Guinea and Australia. This species can reach a standard length of 18 cm (7.1 in), though most do not exceed 10 cm (3.9 in).