Actinopterygii (ray-finned fishes) > Perciformes
(Perch-likes) > Gobiidae
(Gobies) > Sicydiinae
Etymology: Sicyopterus: Greek, sika, sikya = cucumber + Greek, pteron = wing, fin (Ref. 45335).
Environment / Climate / Range
Marine; freshwater; brackish; demersal; amphidromous (Ref. 51243); depth range 1 - 300 m (Ref. 58302). Tropical, preferred ?; 19°N - 16°N
Oceania: found in larger Hawaiian Islands and Society Islands.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 19.8 cm SL male/unsexed; (Ref. 26461)
Morphology | Morphometrics
Mature males characterized by an extended ray on the first dorsal fin which is very long and overlaps the second dorsal fin when folded; courting male can appear turquoise to nearly black, with two "racing" stripes along the length of the body; females and juveniles normally mottled brown to gray-green; both sexes turn black when disturbed (Ref. 44091).
Benthic in lower and middle reaches of streams (Ref. 58302). Adults inhabit mountainous streams. Are well adapted to exist in swiftly-flowing basalt-bottomed stream habitat (Ref. 26461). Presence of these species signify water of good water quality (Ref. 44091). Adults are primarily herbivorous, scraping algae off rocks, while the larvae are omnivorous; occasionally caught with nets ('upena), usually after being stupefied with native plants (e.g. hola and ahuhu), a process requiring partial diversion of the stream to reduce water flow; particularly prized in July and August when the females are gravid (Ref. 44091).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Tinker, S.W., 1978. Fishes of Hawaii, a handbook of the marine fishes of Hawaii and the Central Pacific Ocean. Hawaiian Service Inc., Honolulu. 568 p. (Ref. 583)
IUCN Red List Status (Ref. 109396)
CITES (Ref. 94142)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01122 (0.00514 - 0.02450), b=3.04 (2.87 - 3.21), based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 2.1 ±0.0 se; Based on diet studies.
Resilience (Ref. 69278
): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Moderate vulnerability (37 of 100) .