|[upper; A, B, C] Lestidium longilucifer &|
[lower; A, C, D] Lestidium rofeni
Ho, Graham & Russell, 2020
Three new species of the genus Lestidium with complete lateral line are described from the Indo-west Pacific Ocean. Lestidium longilucifer sp. nov., from Western Australia and Taiwan, belongs to the Lestidium atlanticum species complex and can be separated from other congeners by having 41–43 prehaemal vertebrae, 85–88 total vertebrae and 126–146 total lateral-line scales; and body proportions. Lestidium australis sp. nov. from eastern Australia and Lestidium rofeni sp. nov. from Taiwan and the Philippines together with Lestidium prolixum form the L. prolixum species complex. These three species can be separated from each other by a combination of different fin positions, vertebral formula, number of lateral-line scales and pigmentation.
Keywords: Pisces, taxonomy, ichthyology, Aulopiformes, Australia, Taiwan
Genus Lestidium Gilbert, 1905
Lestidium Gilbert, 1905:607
(Type species: Lestidium nudum Gilbert, 1905)
Diagnosis. Body moderately long, not especially slender; luminescent duct in abdominal cavity unbranched, extending forward to below opercle or before anterior margin of eye; nostrils well before a vertical through posterior end of maxilla; lateral line complete or incomplete; no light organ at anterior margin of orbit; a small luminescent duct along lower margin of orbit or absent; ventral adipose fin well-developed along margin between anus and AFO; DFO at above same vertical at or behind VFO, if behind, always before midpoint of V‒A; and anal-fin rays 26‒34.
|FIGURE 1. Lestidium longilucifer sp. nov. |
A. Holotype, AMS I.22821-063, 260 mm SL, preserved. B. Paratype, AMS I.31175- 002, 219 mm SL, fresh, arrow points the VFO. C. Paratype, NMMB-P26017, 205 mm SL, fresh.
Lestidium longilucifer sp. nov.
Long light-organ barracudina
Diagnosis. Lestidium longilucifer sp. nov. is one of three species recognized in the Lestidium atlanticum species complex with a luminescent duct extending beyond the anterior margin of the eye. It can be distinguished from its two congeners L. atlanticum and L. orientale in having prehaema vertebrae 41–43; predorsal vertebrae 38–40; prepelvic vertebrae 37–39; preanal vertebrae 56–59; total vertebrae 85–88; total lateral-line scales 126–146; and relatively short jaws.
Etymology. The specific name longilucifer is derived from the combination of Latin longus and lucifer, referring to the long luminescent duct that extends well forward of the eye.
Distribution. The species is currently known only from the type series collected from northwestern Australia and southern Taiwan.
Lestidium nigrirostrum sp. nov.
Australian Robust Barracudina
Diagnosis. A species in the Lestidium prolixum species complex with a complete lateral-line, and a simple luminescent duct originating below opercle; it can be further distinguished from two other congeners in the species complex in having 31‒34 anal-fin rays; prehaemal vertebrae 35–38 and total vertebrae 87–90; lateral-line ended at caudal fin base, with 142–157 scales; DFO clearly behind tip of adpressed pelvic fin, V–D 5.6–8.5%SL and 28.6–38.6%V–A; 5‒7 lateral-line scales and 4‒7 vertebrae between VFO and DFO; dorsum dark brownish, melanophores extending downward to the lateral-line along its entire upper margin; anterior portions of snout and lower jaw blackish; abdomen with a very broad black sub-margin.
Etymology. The specific name is derived from Latin niger and rostrum, in referring to the black snout.
Distribution. The species is currently known from waters off eastern Australia, ranging from the Coral Sea off central Queensland to Bass Strait and into the Tasman Sea.
|FIGURE 6. Lestidium rofeni sp. nov.|
A. Holotype, NMMB-P28479, 245 mm SL, fresh. B. preserved holotype. C. Paratype, NMMB-P27926, 248 mm SL, fresh. D. Paratype, NMMB-P27927, 239 mm SL, fresh.
Lestidium rofeni sp. nov.
Diagnosis. A species in the Lestidium prolixum species complex with a complete lateral line and a simple luminescent duct originating below opercle.; L. rofeni can be further distinguished from two other congeners in the species complex in having 30‒33 anal-fin rays; prehaemal vertebrae 36–38 and total vertebrae 87–90; lateral-line ending at caudal fin base, with 123–139 scales; DFO clearly behind tip of adpressed pelvic fin; V–D 6.7–8.7% SL and 30.2–36.7% V–A; 5‒7 lateral-line scales and 5‒8 vertebrae between VFO and DFO; scattered melanophores away from upper margin of lateral line before VFO, entirely translucent on remaining section of lateral line; abdominal ridge with none or scattered melanophores.
Etymology. The species is named after Robert R. Rofen (previously R. R. Harry), former research director of George Vanderbilt Foundation, Stanford University, who contributed a lot of knowledge on paralepidid fishes.
Distribution. The species is currently known only from Taiwan and the Philippines, but is likely widespread in northwestern Pacific Ocean. Off southern Taiwan, smaller specimens were collected by mid-water trawl (<100 m depth) and larger specimens usually caught by demersal trawl (> 300 m), which may suggest the adults shift to deeper waters with growth/age.
Hsuan-Ching Ho, Ken Graham and Barry Russell. 2020. Three New Species of the Barracudina Genus Lestidium (Aulopiformes: Paralepididae) from the Indo-West Pacific. Zootaxa. 4767(1); 71–88. DOI: 10.11646/zootaxa.4767.1.3