Environment: milieu / climate zone / depth range / distribution range
Marine; bathypelagic; depth range 500 - 1300 m (Ref. 559), usually - m (Ref. ). Deep-water; 0°C - ; 25°N - 36°S, 1°W - 177°W (Ref. 57332)
Indo-Pacific: including the East China Sea.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 23.0 cm SL male/unsexed; (Ref. 559)
Morphology | Morphometrics
soft rays: 16 - 20. Body with wrinkled gelatinous skin covering. Small photopores on body. Closely resembles R. watasei but differs in having a gently curved and long snout. Body color dusky-purple.
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Masuda, H., K. Amaoka, C. Araga, T. Uyeno and T. Yoshino, 1984. The fishes of the Japanese Archipelago. Vol. 1. Tokai University Press, Tokyo, Japan. 437 p. (text). (Ref. 559)
IUCN Red List Status (Ref. 124695)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Preferred temperature (Ref. 115969
): 5.7 - 9.1, mean 7 °C (based on 81 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5010 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00347 (0.00164 - 0.00733), b=3.19 (3.00 - 3.38), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.4 ±0.5 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.).
Vulnerability (Ref. 59153
): Moderate vulnerability (38 of 100) .