Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Actinopteri (ray-finned fishes) > Beloniformes
(Needle fishes) > Zenarchopteridae
(Internally fertilized halfbeaks)
Etymology: Nomorhamphus: Greek, nema = filament + Greek, rhamphos = bill, peak (Ref. 45335); rex: Name from Latin meaning king; referring to the teeth, similar to the dentition of the late Cretaceous Tyrannosaurus rex; noun in apposition..
Environment: milieu / climate zone / depth range / distribution range
Freshwater; pelagic; depth range 0 - ? m. Tropical
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 4.4 cm SL male/unsexed; (Ref. 91778); 6.4 cm SL (female)
Morphology | Morphometrics
soft rays: 14 - 15;
Vertebrae: 37 - 40. This species is distinguished from its congeners by the shape of the andropodium in males: sickle-shape spiculus is curved dorsally, the proximal and middle segments in contact with the distal tip of the third anal-fin ray; the spiculus' distal segments are curved ventrally, no contact to third anal-fin ray; in males, the second anal-fin ray with 3 or 4 segments proximal to paired spines, third or fourth segment with a dorsal and a ventral row of 'subsegments' forming squares and rectangles of different sizes, the third or fourth segment appears to be subdivided into two separate rays, from the half of its length up to the spines, with a varying number of subsegments (?5 subsegments per row); first segment of the first anal-fin ray slightly constricted longitudinally, giving the appearance of 2 distinct rays; third anal-fin ray composed of 2 elongate segments, each approximately half the length of the entire ray, followed by a few short segments at the distal tip, which contact the spiculus; the fourth anal-fin ray divided into 3 rows from approximately the third of its length, forming a kind of a covering for the third anal fin ray with one dorsal and two lateral rows beneath (Ref. 91778). Nomorhamphus rex have a relatively longer lower jaw, LJLB 5.7-11.3 times in SL vs. 13.4-15.9 in N. ebrardtii and 8.8-22.2 in N. kolonodalensis (Ref. 44897).
Found in small, fast flowing river of few meters width that are partially covered by forest canopy, with gravel and sand bottoms. Occurs with Oryzias celebensis, Telmatherina cf. bonti,
Anabas testudineus, Channa striata, Trichopodus pectoralis, Trichopodus pectoralis>, Mugilogobius> sp., Aplocheilus panchax>, and Poecilia reticulata (Ref. 91778).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Huylebrouck, J., R.K. Hadiaty and F. Herder, 2012. Nomorhamphus rex, a new species of viviparous halfbeak (Atherinomorpha: Beloniformes: Zenarchopteridae) endemic to Sulawesi Selatan, Indonesia. The Raffles Bulletin of Zoology 60(2):477-485. (Ref. 91778)
IUCN Red List Status (Ref. 125652)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00427 (0.00183 - 0.00997), b=3.02 (2.81 - 3.23), in cm total length, based on LWR estimates for this Subfamily-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) .
Climate Vulnerability (Ref. 125649
): (0 of 100) .