Teleostei (teleosts) >
Syngnathiformes (Pipefishes and seahorses) >
Syngnathidae (Pipefishes and seahorses) > Syngnathinae
Etymology: Hippocampus: Greek, ippos = horse + Greek,kampe = curvature (Ref. 45335); waleananus: Named for its type and only confirmed locality Walea Island, Sulawesi, Indonesia, where this species occurs and the Latin nanus for "dwarf".
Issue
Junior synonym in Lourie et al., 2016; valid in ECoff., 2023.
Environment: milieu / climate zone / depth range / distribution range
Ecology
Marine; benthopelagic; non-migratory; depth range 5 - 20 m (Ref. 80667). Tropical
Western Central Pacific: Indonesia.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 1.8 cm SL male/unsexed; (Ref. 80667)
Short description
Identification keys | Morphology | Morphometrics
Dorsal soft rays (total): 12. This species is distinguished by the following characters: size extremely small (height 1.68 cm, 1.78 cm SL); trunks rings 12; tail elongate, 32 tail rings; D 12; pectoral fin rays 9; no anal fin (at least in one sex); apparently eggs brooded within trunk; medium length snout which lacks a bulbous tip; coronet raised and angular; fused gill openings on midline behind the coronet supported by raised cleithral girdle; enlarged knob-like structures on head and trunk; paired laterally directed knob-like structures and each with short fleshy filament on superior trunk ridge of the fifth trunk ring; last 28 tail rings each with small paired knobs on inferior tail ridge, fifth, ninth and twelfth tail rings with bilaterally paired enlarged knob-like structures on superior tail ridges. Colouration: pale pinkish to yellowish with red to brown blotches, radiating bands from eye; body protuberances are white, appearing as white spots (Ref. 80667).
Body shape (shape guide): other; Cross section: angular.
Found in association with the soft coral Nephtea, but has also been observed swimming lengthy distances from one coral to the next (Ref 90102).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Male carries the eggs in a brood pouch (Ref. 205).
Short, G., R. Smith, H. Motomura, D. Harasti and H. Hamilton, 2018. Hippocampus japapigu, a new species of pygmy seahorse from Japan, with a redescription of H. pontohi (Teleostei, Syngnathidae). ZooKeys 779:27-49. (Ref. 118476)
IUCN Red List Status (Ref. 130435: Version 2025-1)
Threat to humans
Harmless
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Estimates based on models
Phylogenetic diversity index (Ref.
82804): PD
50 = 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.00447 (0.00175 - 0.01142), b=2.99 (2.77 - 3.21), in cm total length, based on LWR estimates for this (Sub)family-body shape (Ref.
93245).
Trophic level (Ref.
69278): 3.0 ±0.5 se; based on size and trophs of closest relatives
Resilience (Ref.
120179): High, minimum population doubling time less than 15 months (Preliminary K or Fecundity.).
Fishing Vulnerability (Ref.
59153): Low vulnerability (10 of 100).
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