Common names from other countries
Actinopteri (ray-finned fishes) > Ophidiiformes
(Cusk eels) > Dinematichthyidae
Etymology: Diancistrus: Greek, di = two + Greek, agkistron = hook (Ref. 45335); tongaensis: Named for Tonga where the majority of the specimens were taken. More on authors: Schwarzhans, Møller & Nielsen.
Environment: milieu / climate zone / depth range / distribution range
Marine; reef-associated; depth range 1 - 10 m (Ref. 57884). Tropical
Central Pacific: New Caledonia to southern Vanuatu, Fiji, Tonga and Samoa; tentatively Santa Cruz Islands (Vanikolo), Vanuatu (Banks Islands), Phoenix Islands (Kiribati), Wallis Island and Tahiti.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 4.5 cm SL male/unsexed; (Ref. 57884); 5.8 cm SL (female)
Morphology | Morphometrics
soft rays: 57 - 66;
Vertebrae: 39 - 42. This species is characterized by the following: vertebrae 11+(28)29-31=(39) 40-42, dorsal fin rays 71-80, anal fin rays 57-66; small eyes (1.3-2.3% SL); outer pseudoclasper with large ear-lobe extension, ventrally opening; inner pseudoclasper free from outer pseudoclasper, with supporter, forming a broad, distally expanded, not inclined flap, with short thorn; narrow scale patch on cheek, no scales on operculum; head profile slender; otolith length to height ratio 1.9-2.0 (Ref. 57884).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Schwarzhans, W., P.R. Møller and J.G. Nielsen, 2005. Review of the Dinematichthyini (Teleostei, Bythitidae) of the Indo-West-Pacific. Part I. Diancistrus and two new genera with 26 new species. The Beagle, Records of the Museum and Art Galleries of the Northern Territory 21:73-163. (Ref. 57884)
IUCN Red List Status (Ref. 123251)
CITES (Ref. 123416)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 24.7 - 29.4, mean 27.7 (based on 552 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00389 (0.00180 - 0.00842), b=3.12 (2.94 - 3.30), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.3 ±0.5 se; based on size and trophs of closest relatives
Resilience (Ref. 69278
Vulnerability (Ref. 59153
): Low vulnerability (12 of 100) .