Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Ophidiiformes
(Cusk eels) > Bythitidae
(Viviparous brotulas) > Brosmophycinae
Etymology: Didymothallus: Name from Greek 'didymos' for double or twofold and 'thallus' for branch in plants, referring
to the two supporters of nearly equal length in the single pair of pseudoclaspers.. More on author: Günther.
Environment: milieu / climate zone / depth range / distribution range
Marine; reef-associated. Tropical
Indo-West Pacific: Australia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 5.1 cm SL male/unsexed; (Ref. 76869); 6.6 cm SL (female)
Morphology | Morphometrics
soft rays: 57 - 73;
Vertebrae: 40 - 45. This species is distinguished by the following characters: D 78-97; A 57-73, V in D 2.2-2.6; vertebrae 12-13+28-32=40-45; one (outer) pseudoclasper wing-shaped with 2 slender,
straight supporters, the posterior one is slightly longer and thicker than anterior one; straight penis; 4-6 rows of scales on upper part of cheek, 0-2 rows on lower part; anterior tip of otolith rounded, otolith with undivided long sulcus, its centre anterior of centre of otolith, not inclined, otolith length to height, 2.2-2.3, otolith length to sulcus length, 1.9-2.1 (Ref. 76869).
Common species found on shallow reefs (Ref. 34024). Most common in inshore and back reef environments, associated with crevices of silty coralline rock. Female specimens with unusually low numbers of large embryos, 1-3, usually 2). One female (3.2 cm SL) contained one embryo (1.4 cm SL in length) This is among the lowest degree of fecundity observed in tribe Dinematichthyini. (Ref. 76869).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Schwarzhans, W. and P.R. Møller, 2007. Review of the Dinematichthyini (Teleostei: Bythitidae) of the Indo-west Pacific. Part III. Beaglichthys, Brosmolus, Monothrix and eight new genera with description of 20 new species. The Beagle, Records of the Museums and Art Galleries of the Northern Territory 23:29-110. (Ref. 76869)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 115941)
Threat to humans
Fisheries: of no interest
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5625 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00447 (0.00174 - 0.01147), b=3.10 (2.87 - 3.33), in cm Total Length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.2 ±0.5 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Vulnerability (Ref. 59153
): Low vulnerability (13 of 100) .