Classification / Names
Common names | Synonyms | Catalog of Fishes (gen., sp.) | ITIS | CoL | WoRMS | Cloffa
Actinopterygii (ray-finned fishes) > Osmeriformes
(Smelts) > Opisthoproctidae
(Barreleyes or spookfishes)
Etymology: Monacoa: The name constructed by Whitley was without any etymological reason; however, it is likely referring to the state of Monaco, in which the research expedition that sampled the two syntypes originated.; niger: Name from Latin 'niger' for 'black'; referring to the black streak of pigmentation present on the sole.
Environment: milieu / climate zone / depth range / distribution range
Marine; bathypelagic; depth range 0 - 520 m (Ref. 111070). Deep-water
Countries | FAO areas | Ecosystems | Occurrences | Point map | Introductions | Faunafri
Eastern Central Pacific: off American Samoa and possibly Australia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 4.8 cm SL male/unsexed; (Ref. 111070)
Morphology | Morphometrics
This species is distinguished by having black pigmentation along the entire sole and possibly have a darker or more blackish body color compared to congeners (scale pockets are darker); and the black streak on the sole possibly consists of distinct patches posteriorly . The holotype is slightly damaged on the sole and variation of its pigmentation pattern must be assessed with future fresh material (Ref. 111070).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Poulsen, J.Y., T. Sado, C. Hahn, I. Byrkjedal, M. Moku and M. Miya, 2016. Preservation obscures pelagic deep-sea fish diversity: doubling the number of sole-bearing opisthoproctids and resurrection of the genus Monacoa (Opisthoproctidae, Argentiniformes). Plos One 11(8):1-23. (Ref. 111070)
IUCN Red List Status (Ref. 120744)
CITES (Ref. 115941)
Threat to humans
CountriesFAO areasEcosystemsOccurrencesIntroductionsStocksEcologyDietFood itemsFood consumptionRation
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.6250 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01995 (0.00906 - 0.04395), b=3.01 (2.83 - 3.19), in cm Total Length, based on all LWR estimates for this body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.3 ±0.1 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 (12 of 100) .