Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Teleostei (teleosts) > Beloniformes
(Needle fishes) > Zenarchopteridae
(Internally fertilized halfbeaks)
Etymology: Hemirhamphodon: Greek, hemi = half + Greek, rhamphos = bill + greek, odous = teeth (Ref. 45335); byssus: Name from the Latin byssus, meaning fine thread, in reference to the distinct filamentous dorsal-fin rays of large males. A noun in apposition..
Environment: milieu / climate zone / depth range / distribution range
Freshwater; pelagic; depth range 0 - ? m. Tropical
Asia: southern to central Sarawak (South of Rejang basin) in Malaysia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 7.1 cm SL male/unsexed; (Ref. 94086)
Morphology | Morphometrics
Distinguished from other species of Hemirahamphodon in having the following characters: dorsal fi n with melanophores in two sizes on both male and female examples above 30 mm SL, interradial membranes on the anterior half of the dorsal fin with large
and intense melanophores throughout fi n depth, appearing as thin black streaks. 2) Unique dorsal fi n morphology on large males above 50 mm SL - distal portions of fi rst 6 to 7 rays elongated, free of interradial membrane, projected into fi laments up to four times the
depth of the dorsal fi n; adpressed fi n rays reaching half of caudal-fin. 3). Males with an enlarged posterior projection on the fourth anal-fi n ray, with third, fourth and eighth anal-fin rays branched; females with third, fourth and eighth anal-fi n rays branched; pelvic-fin origin anterior to dorsal-fi n origin. 5) Dorsal-fin rays 13 to 14 (Ref. 94086).
This species inhabits streams of lowland forest and peat swamps. In streams with clear water, the body is lighter in color while in tannin stained waters, the body tends to be darker colored, at times appearing black (Ref. 94086).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Tan, H.H. and K.K. Lim, 2013. Three new species of freshwater halfbreaks (Teleostei: Zenarchopteridae: Hemirhamphodon) from Borneo. The Raffles Bulletin of Zoology 61(2):735-747. (Ref. 94086)
IUCN Red List Status (Ref. 126983)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82804
= 0.5020 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm total length, based on all LWR estimates for this BS (Ref. 93245
Trophic level (Ref. 69278
): 3.1 ±0.4 se; based on size and trophs of closest relatives
Fishing Vulnerability (Ref. 59153
): Low vulnerability (10 of 100).