Hairfinned Leatherjacket

body width 2.0-2.6 in head length; body depth 2.0-3.1 in SL, head length 2.7-3.2 in SL; snout length 3.7-4.1 in SL; eye diameter 2.7-3.7 in head length; second dorsalmost caudal ray elongate and filamentous in male (Ref. 33065).

Oceanodromous. Migrating within oceans typically between spawning and different feeding areas, as tunas do. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 2; Dorsal soft rays (total): 24 - 30; Analspines: 0; Analsoft rays: 24 - 30; Vertebrae: 19

Inhabits weedy and sandy areas of coastal reefs (Ref. 9710). Found on open muddy substrates from shallow estuaries to deep offshore. Males elongate with age (Ref. 48637). Monogamous (Ref. 52884).

分布於印度-西太平洋區。由日本至澳洲西北部及巴布新幾內亞等。台灣澎湖海域有分布。

中小型魚類，無經濟價值。。或以其可愛的模樣而常被飼養於水族館中，供人欣賞。

體側扁，雌雄魚的體型略不同，雌魚體較短而高，雄魚則為長橢圓形；頭背緣平直。吻長大，側視似三角形。鰓孔位在眼後下方，其下端與眼後緣相對。體鱗小，排列極規則，多作2行或多行排列，每一鱗的基板上具許多粗狀的棘突；側線不顯著。背鰭兩個，第I背鰭棘位於眼後半部稍靠後緣的上方，背棘長而稍細，後緣具倒棘，前緣具粒狀突起；第II背鰭棘小，粒狀，埋於棘溝內；腹鰭合為一短棘，由特化鱗組成，共三對，可活動，達腰帶骨後方；背鰭與臀鰭前半部之鰭條較後半部之鰭條高許多，背鰭軟條數24-30，臀鰭軟條數30-31；尾鰭圓形，雄魚最上及中央之鰭條或延長如絲，雌魚則否。體灰黃色至灰褐色，體側具1-3條平行的黑褐色縱紋，或散布一些黑褐色斑點，形成不甚明顯之平行縱紋。背鰭基部及臀鰭基部具2個黑褐色斑塊，部分延伸至鰭條上；尾鰭基部則有3條暗色橫紋。

近海中下層魚類，常出現於砂泥底層海域。肉食性魚類，主要以小型甲殼類、貝類及海膽等為食。

Paramonacanthus japonicus is a filefish from the Indo-West Pacific. It occasionally makes its way into the aquarium trade. It grows to a size of 12 cm in length.