Rothschild's Barracudina, Stemonosudis rothschildi Richards 1967
Rothschild's Barracudina, Stemonosudis rothschildi, from off northwestern Western Australia. Source: Australian National Fish Collection, CSIRO. License: CC BY Attribution-Noncommercial
Summary:
A translucent to dusky-brown barracudina with 9-10 large saddles along the back (5 before the dorsal-fin origin), and 8 saddles along the ventral margin. The snout, lips, abdominal ridge and lateral-line are dark, the peritoneal membranes are divided into 9-11 sections, visible through the belly. The species has a blackish outer half of the dorsal fin, rear part of anal-fin, and a black caudal fin.
Cite this page as:
Bray, D.J. 2025, Stemonosudis rothschildi in Fishes of Australia, accessed 30 Jun 2025, https://fishesofaustralia.net.au/home/species/4018
Rothschild's Barracudina, Stemonosudis rothschildi Richards 1967
More Info
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Distribution |
Northwestern Western Australia, from NNW of Dampier to the Timor Sea, north of Joseph Bonaparte Gulf, Western Australia. Elsewhere the species is circumglobal in tropical waters, except the eastern Pacific. |
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Features |
A species of the S. rothschildi species complex with relatively moderately slender body, both depth 15.9‒18.8 in SL; 5 saddles on dorsum before DFO and 3 on abdominal margin before VFO; 39‒41 prepelvic and 50‒52 predorsal vertebrae; 9‒13 vertebrae in V‒D; and PVLL 39‒41 and PDLL 50‒52.Description. Dorsal-fin rays 9 (rarely 10); pectoral-fin rays 12–13 (mainly 12); pelvic-fin rays 9; anal-fin rays 32–35. Lateral-line scales: 39‒41 PVLL, 50‒52 PDLL, 56‒60 PALL, 75–84 in total, includes 3‒5 small ones on rear portion. Vertebral counts: 42–44 prehaemal, 46–48 caudal, 39–41 prepelvic; 50–52 predorsal; 56–60 preanal and 89–92 in total. |
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Size |
Dorsal soft rays (total): 9 - 10; Anal soft rays: 32 - 35; Vertebrae: 89 - 92. This species is distinguished by the following characters; a relatively moderately slender body, both depth 15.9-18.8 in SL; presence of 5 saddles on dorsum before dorsal-fin origin and 3 on abdominal margin before pelvic-fin origin; prepelvic vertebrae 39-41, predorsal 50-52; 9-13 vertebrae in horizontal distance between origins of pelvic and dorsal fins; lateral-line scales before pelvic 39-41 and berfore dorsal 50-52 |
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Colour |
Fresh coloration: Body translucent to light dusky-brown. Upper fourth of body covered with small chromatophores; lateral line densely covered with chromatophores, gradually be-coming scattered on ventral half of body. Dense chromatophores on snout, both lips and abdominal ridge; scattered chromatophores on top of head, nape, and around eye. Very fine chromatophores forming large saddles on dorsum and ventral margin; 9 or 10 on dorsum, 5 before DFO, 1 at dorsal-fin base, 2 between dorsal and adipose fins, 1 or 2 on caudal peduncle; 8 saddles on ventral margin, 3 in front of VFO, 1 at pelvic-fin base, 1 near AFO, 1 on middle of anal-fin base and 1 or 2 on caudal peduncle; the last 2 or 3 pairs of dorsal and ventral saddles usually fused to each other at mid-flank. Peritoneal membranes divided into 9 to 11 (mostly 10) sections, visible through belly. Pectoral and pelvic fin transparent to slightly hyaline; upper half of dorsal fin black; posterior portion of anal-fin blackish; caudal fin black. |
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Similar Species |
The Multi-blotch Barracudina, Stemonosudis multifasciata, differs mainly in having 10 blotches along the back before the dorsal-fin origin (vs. 5 in S. rothschildi), and 93-95 total vertebrae (vs. 89-92). The Back-fin Barracudina, S. retrodorsalis, is unique among paralepidids in having the dorsal fin originating far back, at about the same vertical as the anal-fin origin. |
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Etymology |
Named in honour of Brian J. Rothschild, Bureau of Commercial Fisheries, Honolulu, Hawaii, who supplied the holotype (taken from the stomach of a Pacific lancetfish caught on a longline). |
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Species Citation |
Stemonosudis rothschildi Richards 1967, California Fisheries and Game 1: 35, figs 1-2. Type locality: Central Pacific, 22°47'N, 150°09'W (stomach content). |
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Author |
Bray, D.J. 2025 |
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Resources |
Rothschild's Barracudina, Stemonosudis rothschildi Richards 1967
References
Ghedotti, M.J., Barton, R.W., Simons, A.M. & Davis, M.P. 2015. The first report of luminescent liver tissues in fishes: Evolution and structure of bioluminescent organs in the deep-Sea naked barracudinas (Aulopiformes: Lestidiidae). Journal of Morphology 276: 310-318. https://doi.org/10.1002/jmor.20341
Ho, H.-C., Halasan, L.C. & Tsai, S.-Y. 2019. Review of the slender barracudina genera Dolichosudis and Stemonosudis in Taiwan (Aulopiformes: Paralepididae). Platax 16: 1-22. https://doi.org/10.29926/PLATAX.201912_2019.0001
Ho, H.-C., Russell, B., Graham, K. & Psomadakis, P.N. 2019. Review of the Stemonosudis rothschildi species complex, with descriptions of two new species from the Indo-west Pacific Ocean (Aulopiformes: Paralepididae). Zootaxa 4702(1): 216-229. https://doi.org/10.11646/zootaxa.4702.1.19
Moore, J. & Polanco Fernandez, A. 2019. Stemonosudis rothschildi. The IUCN Red List of Threatened Species 2019: e.T123326101A123326496. https://dx.doi.org/10.2305/IUCN.UK.2019-2.RLTS.T123326101A123326496.en. Accessed on 29 January 2025.
Richards, W.J. 1967. Stemonosudis rothschildi, a new paralepidid fish from the central Pacific. California Fisheries and Game 1: 35-39 figs 1-2 See ref at BHL
