Sicydium brevifile Ogilvie-Grant 1884

Diagnosis: posterior tip of upper jaw extending to below posterior margin of eye or beyond (Ref. 57403), 79590). 63-136 long, slender, unicuspid setiform teeth on each half (left and right) of upper jaw, with alternate teeth usually staggered in 2 rows (although it may be difficult to easily distinguish these rows as separate)(Ref. 79590), not separated by median tubercle (Ref. 57403, 79590). Description: upper lip smooth, with a median notch but no distinct median tubercle (fleshy swelling); each half of lower jaw usually bears 4-9 caniniform teeth and 40-50 labial teeth (although a single individual that appears to be S. brevifile has 2 caniniform and 35 labial teeth on each half of lower jaw); in adults, anterior labial teeth, attached to opposite halves of lower jaw, separated broadly by a wide projection of soft tissue at dentary symphysis; 17-25 cycloid predorsal scales on nape; 53-66 scales in longitudinal series (including 2-3 scales on caudal fin base); 17-24 scales in rearward transverse series; abdomen covered by cycloid scales; 1st dorsal fin VI, 2nd dorsal fin I-10, anal fin I-10, pectoral fin 18-21 (usually 20 or 21), caudal fin with 17-18 segmented rays, 13-15 of which are branched; preopercular canal incorporating 3 pores (Ref. 79590).Coloration: Preserved adult specimens: dark brown on body and may be irregularly freckled with small spots (postlarvae and early juveniles may have about 7 faint bars on flanks); cheek and opercle with small speckles and some striations; dorsal fins dark; anal fin faintly speckled except near tips of rays, which are darker; caudal fin dusky, slightly darker along dorsal margin; pectoral fin dusky with 2 vague rows of darkish spots near base, and dark tips to fin rays (Ref. 79590). In life: pelvic fin red at base; caudal fin with reddish/orange bands along posterior and upper margin; anal fin with orange/salmon distal margin (Ref. 79590).

Amphidromous. Refers to fishes that regularly migrate between freshwater and the sea (in both directions), but not for the purpose of breeding, as in anadromous and catadromous species. Sub-division of diadromous. Migrations should be cyclical and predictable and cover more than 100 km.Characteristic elements in amphidromy are: reproduction in fresh water, passage to sea by newly hatched larvae, a period of feeding and growing at sea usually a few months long, return to fresh water of well-grown juveniles, a further period of feeding and growing in fresh water, followed by reproduction there (Ref. 82692).

Dorsal spines (total): 7; Dorsal soft rays (total): 10; Anal spines: 1; Analsoft rays: 10

Larvae ascend rivers, adults in freshwater (Ref. 4343). Amphidromous endemics living as adults in clearwater streams of the volcanic islands in the Gulf of Guinea and of Mount Cameroon streams in Western Cameroon (Ref. 92840).

fisheries:

Sicydium brevifile is a species of goby from the subfamily Sicydiinae. It is an amphidromous endemic in western Cameroon and the islands of the Gulf of Guinea where the adults inhabit the clearwater streams of the volcanic islands and on the slopes of Mount Cameroon, having ascended from the sea as larvae. Specimens are imported into the Aquarium trade from Cameroon. The specific name means "short thread", Latin brevis and filum, probably a reference to the "small median papilla above the maxillary suture".