Drain Mangrovegoby, Mugilogobius rivulus Larson 2001


Other Names: Drain Mangrove Goby

A Drain Mangrovegoby, Mugilogobius rivulus, from Leaders Creek, Northern Territory. Source: Dave Wilson. License: All rights reserved

Summary:
See'More Info' tab

Cite this page as:
Martin F. Gomon, Mugilogobius rivulus in Fishes of Australia, accessed 20 Nov 2018, http://fishesofaustralia.net.au/home/species/2247

Drain Mangrovegoby, Mugilogobius rivulus Larson 2001

More Info


Distribution

Known only from northwestern Australia between Shark Bay, WA and Bing Bong Creek, Gulf of Carpentaria, NT; a tropical benthic species in estuaries, mangrove and rock bottom marine areas, adjacent to freshwater seepages; usually in shallow, rather still, brackish to freshwater creeks associated with drifts of leaf litter; apparently tolerant of sub-optimal habitats like storm drains.

Features

D V-VI; I, 7-8; A I, 7-9; P 14-16; C (segmented rays) 16, (branched rays) 12-15; Tr Sc 9-12; GR 3-4 + 6-8 = 9-12; Vert 10+16.
Body robust, compressed, more rounded anteriorly, depth 4.4-6.2 in SL. Head wider than deep, somewhat flattened in adults; length 3.1-3.7 in SL. Snout rounded. Anterior nostril tubular, short, just behind upper lip, directed down and forward, preorbital curved forward to accommodate nostril; posterior nostril round to oval, near centre of anterior margin of eye. Eyes lateral, high on head, forming part of dorsal profile, 3.1-4.6 in head. Interorbital broad, flat; top of head from front of scaled nape to snout tip often covered with fine villi. Mouth subterminal, slightly oblique, reaching to below posterior half of eye in males, to below mid- to anterior half of eye in females; outer teeth in upper jaw largest, stout and curved, 3-4 rows of small sharp teeth behind this and in lower jaw, teeth generally smaller in females; lips smooth; lower lip free at sides, fused across front; chin smooth; tongue tip blunt to concave. Gill opening usually reaching forward to under opercle; inner edge of pectoral girdle smooth with no ridge or flange or with irregular fleshy ridge or raised knobby flange, or with distinct fleshy knobs and flaps.
Body fully scaled, ctenoid scales on side forward in wedge to behind pectoral fin; lateral line absent; longitudinal series 29-33. Predorsal scales usually evenly small, forward to about midpoint between preopercular margin and rear of eyes; 12-19 on dorsal midline. Upper half to two-thirds of operculum with small cycloid scales; cheek naked. Pectoral base and prepelvic area covered with cycloid scales. Belly with patch of ctenoid scales under pelvics, remainder cycloid, sometimes all belly scales cycloid. Head pores absent.
Two dorsal fins, first generally low, tip of first spine white and always longest, usually filamentous, not reaching second dorsal origin when depressed; second dorsal and anal fins low, somewhat rounded anteriorly, pointed posteriorly, distinctly not reaching dorsal and anal rays. Pectoral fin rounded to oval, all rays but first usually branched. Pelvic fins fully united into disc, short, rounded to oval, reaching at least halfway to anus. Caudal fin rounded to oval.

Size

To around 4.5 cm SL

Colour

Pale brownish grey with margins of body scales on sides outlined in dark greyish brown forming reticulate pattern; narrow dark greyish brown saddles crossing back and distinctive broad dark brown oblique shoulder bar or oval blotch extending from behind pectoral base toward predorsal area; two oval to triangular dark greyish brown spots at base of tail fin. Lower half of head brown with rounded pale brownish grey spots on opercles; spots on cheek dull greyish yellow with lower half of head plain brownish grey; two pale yellow spots on anterior part of opercle and dark brown to blackish oblique line from rear of mouth through eye to nape; underside of head with about 7 dark brown narrow lines. First dorsal fin dusky brown with brown yellow margin, and pinkish white submarginal band; first spine whitish to dull yellow; second dorsal brownish with pinkish white submarginal band. Base of caudal fin dull yellowish with brown spots. Fin rays brownish, membranes dusky.

Biology

Likely to be oviparous, benthic spawners.

Etymology

Species name from the Latin rivulus, meaning rill or small brook, in reference to the habitats in which this species may be found.

Species Citation

Mugilogobius rivulus  Larson, H.K. (2001). A revision of the gobiid fish genus Mugilogobius (Teleostei: Gobioidei), and its systematic placement.  Rec. West. Aust. Mus. Suppl. 62: 1–233 [177, figs. 167, 177–181].
Drain at Leanyer Swamp, NT.

Author

Martin F. Gomon

Drain Mangrovegoby, Mugilogobius rivulus Larson 2001

References


Larson, H.K. (2001). A revision of the gobiid fish genus Mugilogobius (Teleostei: Gobioidei), and its systematic placement.  Rec. West. Aust. Mus. Suppl. 62: 1–233 [177, figs. 167, 177–181].

Quick Facts


CAAB Code:37428353

Habitat:freshwater creeks and estuaries

Max Size:4.5 cm SL

Native:endemic

Species Image Gallery

Species Maps

CAAB distribution map