Stiphodon martenstyni Watson 1998

Nine rays in second dorsal fin (Dorsal fin VI-I, 9). Fifteen pectoral rays. Scales in lateral series 34. Ten cycloid scales in predorsal midline. Forty-five tricuspid teeth in upper jaw. Cutaneous sensory papillae over head elongate. Upper lip crenulated. Ridge of tissue forming a ring around anus (Ref. 44827).

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): 9; Anal spines: 1; Analsoft rays: 10

Collected in a swift, clear mountain stream together with Syciopus jonklaasi (Ref. 44827).

Like other sicydiine gobies, Stiphodon martenstyni is probably amphidromous (McDowell, 1992a, 1992b). While juveniles and adults live exclusively in freshwater, adults reproduce in freshwater, the eggs being cared for by males. Eggs in all sicydiine gobies studied usually hatch in about 24 hours (Erdman, 1961, 1986; Beyer, 1989) at which time the fry passively drift downstream and out to sea where they become part of the plankton layer. The time spent out at sea as planktonic fry is unknown. The returning fry can be likened to surfers: that is, when fry are able to detect the crest of waves to their new home. This follows a similar scenario presented in Erdman (1961) for Sicydium Valenciennes, 1837 from Puerto Rico (Ref. 44827).

Stiphodon martenstyni, the Martenstyn's stiphodon or Martenstyn's goby, is a species of amphidromous freshwater goby endemic to the southwestern portion of Sri Lanka. The males of this species can reach a length of 3.4 centimetres (1.3 in) SL.