Teleostei (teleosts) >
Trachichthyiformes (Roughies) >
Trachichthyidae (Slimeheads)
Etymology: Optivus: Latin, optivus, -a-um = chosen; agrammus: Named for the absence ot stripes on the caudal fin (Greek 'a' for without and 'gramme' for line).
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; reef-associated; depth range 40 - 320 m (Ref. 76814). Temperate
Eastern Indian Ocean: Australia.
Size / Weight / Age
Maturity: Lm ? range ? - ? cm
Max length : 9.1 cm SL male/unsexed; (Ref. 76814)
Short description
Identification keys | Morphology | Morphometrics
Dorsal spines (total): 3; Dorsal soft rays (total): 10 - 11; Anal spines: 3; Anal soft rays: 9 - 10; Vertebrae: 26. This species is distinguished by the following characters: 20-24 (modally 22) gill rakers; gently curved lateral profile of nape and dorsal surface of head, nearly horizontal in front of dorsal-fin origin, almost straight between eyes; broadly rounded tip of snout; 2.7-2.9 times in SL, depth of head at vertical through upper end of gill opening; snout length is 1.5-2.6 times in eye diameter; the inner row of teeth on premaxilla is noticeably longer than others; relatively short and deep caudal peduncle, depth 0. 9-1.2 in length; dorsal and anal fins are relatively low, third segmented dorsal-fin ray 3.8-4.6 times in SL, first anal-fin ray 5.6-8.2 times in SL; body color greenish brown on back, silvery below; fins almost uniformly pink, though slightly dusky tips to caudal-fin lobes lasting in recently preserved large specimens (Ref. 76814).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Gomon, M.F., 2004. Two new species of roughy (Trachichthyidae: Optivus) from coastal waters of southern Australia. Rec. Aust. Mus. 56:173-178. (Ref. 76814)
IUCN Red List Status (Ref. 130435: Version 2024-2)
Threat to humans
Harmless
Human uses
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Estimates based on models
Preferred temperature (Ref.
123201): 14.6 - 17.4, mean 15.9 °C (based on 26 cells).
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.6250 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01072 (0.00425 - 0.02703), b=3.02 (2.80 - 3.24), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.4 ±0.6 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): Medium, minimum population doubling time 1.4 - 4.4 years (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
