Periophthalmus darwini Larson & Takita, 2004
Darwin's mudskipper
photo by Polgar, G.

Family:  Oxudercidae (Mudskippers), subfamily: Periophthalminae
Max. size:  4.55 cm SL (male/unsexed)
Environment:  demersal; freshwater; brackish
Distribution:  Oceania: Australia in Northern Territory and Western Australia.
Diagnosis:  Dorsal spines (total): 5-7; Dorsal soft rays (total): 10-12; Anal spines: 1-1; Anal soft rays: 11-13. Can be distinguished by the following characters: body depth at anal fin origin 10.6-14.6% of SL, mean 12.7%; unique among Periophthalmus species in having a greatly reduced first dorsal fin (depressed dorsal 5.1-9.6% of SL) in both sexes, and usually with only five spines, fin widely separated from second dorsal fin origin; pelvic fins united for half their length, distinct fraenum present, posterior tips of fins pointed to bluntly pointed, fifth ray bifurcating close to base and branching about 9 times; first dorsal fin plain blackish except for slightly paler base and narrow whitish margin; second dorsal fin translucent with broad submarginal black band and a row of black spots or blotches along fin base; no melanophores on anal fin; pelvic fins whitish or with some fine speckling; orange spots may be present on lower side of head and body when live; second dorsal fin rays modally I,11; anal fin rays modally I,12; pectoral rays 11-13; caudal fin rays usually only with ventralmost 6-7 rays branched, dorsalmost 8-9 rays rarely branched; lateral scales 58-78; predorsal scales usually 24-25 (Ref. 76839).
Biology: 
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


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