Research Article |
Corresponding author: Harutaka Hata ( k2795502@kadai.jp ) Academic editor: Jan Kotusz
© 2023 Harutaka Hata, Hiroyuki Motomura.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Hata H, Motomura H (2023) Redescription and extended distribution of a poorly known Australian anchovy, Stolephorus advenus (Actinopterygii: Clupeiformes: Engraulidae). Acta Ichthyologica et Piscatoria 53: 209-216. https://doi.org/10.3897/aiep.53.109943
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The false Indian anchovy, Stolephorus advenus Wongratana, 1987 (Engraulidae), previously known only from the type specimen from the Northern Territory, Australia, is redescribed herewith and its validity confirmed, on the basis of the holotype and nine additional specimens from the northern coast of Australia. Although the significance of differences between S. advenus and some congeners with a similarly short maxilla has been unclear, the diagnostic reliability of some characters, including melanophores absent on the dorsal- and anal-fin bases, pectoral fin and occipital region, fewer pseudobranchial filaments, and greater number of prepelvic scutes, is confirmed. An extended distribution of the species around the northern coast of Australia is also reported.
Clupeomorpha, ichthyofauna, Stolephorus balinensis, Stolephorus indicus, taxonomy
Stolephorus Lacepède, 1803, an Indo–Pacific genus of marine and/or brackish water anchovies (Engraulidae), comprises 45 valid species (
During an examination of Australian species of Stolephorus, nine additional specimens of S. advenus, collected from several localities along the northern coast of Australia, were identified. The specimens, with additional morphological and biological information confirming the validity of the species, are described in detail herein.
Counts and measurements follow
Comparative material examined. Stolephorus balinensis (Bleeker, 1849), 119 specimens, 43.4–148.4 mm SL: listed in
Stolephorus belaerius Hata, Lavoué et Motomura, 2021, 27 specimens, 63.4–127.1 mm SL: listed in
Stolephorus commersonnii Lacepède, 1803, 16 specimens, 62.1–112.3 mm SL: listed in
Stolephorus horizon Hata et Motomura, 2023, 34 specimens, 62.3–108.1 mm SL; Stolephorus indicus (van Hasselt, 1823), 41 specimens, 53.3–133.6 mm SL; Stolephorus meteorum Hata, Lavoué, Bogorodsky, Alpermann, et Motomura 2023, 20 specimens, 49.2–115.0 mm SL; Stolephorus scitulus (Fowler, 1911), 46 specimens, 47.6–102.7 mm SL: listed in
Family Engraulidae
Stolephorus Lacepède, 1803
Stolephorus advenus
Wongratana, 1987—
10 specimens, 49.1–79.6 mm SL, all specimens collected from Australia.
NTM S. 10031-153, 72.2 mm SL, holotype of Stolephorus advenus, north of Saulte Point, Cobourg Peninsula, Northern Territory, 18 Oct. 1981, H. Larson leg.
CSIRO A 2911, 53.3 mm SL, Gulf of Carpentaria, approx. 13 km east of Sydney Island, Queensland (16°42′36″S, 139°34′48″E), 16.5 m depth; CSIRO A 2916, 56.3 mm SL, CSIRO A 2917, 52.3 mm SL, Gulf of Carpentaria, approx. 14 km east of Sydney Island, Queensland (16°40′12″S, 139°36′30″E), 14.6 m depth; CSIRO B 288, 3 specimens, 53.8–56.3 mm SL, Gulf of Carpentaria, approx. 9 km east of Sydney Island, Queensland (16°43′00″S, 139°33′00″E), 16.5 m depth; CSIRO CA 2555, 74.2 mm SL, approx. 20 km east of Tasman Point, Groote Eylandt, Northern Territory (14°20′S, 136°10′E), 18 m depth; CSIRO CA 2688, 79.6mm SL, north of Groote Eylandt, Gulf of Carpentaria, Northern Territory; NTM S. 13803-003, 49.1 mm SL, Howard Channel, Clarence Strait, Northern Territory (12°05′S, 131°02′E).
A species of Stolephorus with the following combination of characters: maxilla short, 13.7%–14.5% of SL, its posterior tip not reaching anterior margin of preopercle; posterior margin of preopercle convex, rounded; no predorsal scutes; prepelvic scutes 6 or 7 (modally 7); pelvic scute without spine; dorsal fin with three unbranched and 12–15 (14) branched rays; anal fin with three unbranched and 15–17 (16) branched rays, its origin just below base of ninth to eleventh dorsal-fin ray; 1UGR 17–19 (18), 1LGR 24–27 (25), 1TGR 42–45 (42), 2UGR 10–13 (11), 2LGR 20–23 (22), 2TGR 30–35 (33), 3UGR 8–11 (9), 3LGR 11–13 (12), 3TGR 20–22 (21), 4UGR 6–9 (7), 4LGT 9–10 (9), 4TGR 15–18 (17); gill rakers 3 or 4 (4) on posterior face of third gill arch; transverse scales 8; pseudobranchial filaments 15–18 (16); total vertebrae 41 or 42 (42); pelvic fin short, 7.6%–8.0% of SL, tip of depressed pelvic fin not reaching posteriorly to vertical through dorsal-fin origin; head short, 21.6%–22.9% of SL; body rather deep, 17.4%–20.9% of SL; pectoral fin rather long, 13.5%–14.2% of SL; pairs of dark patches on parietal area (sometimes also on occipital area); no dark lines on dorsum; no black spots on suborbital area and tip of lower jaw; no melanophores on bases of dorsal and anal fins, and pectoral fin.
Counts and measurements, expressed as percentages of SL, given in Tables
Count | Holotype | Non-types | Modal value |
---|---|---|---|
NTM S. 10031-153 | n = 9 | ||
Dorsal-fin rays (unbranched) | 3 | 3 | 3 |
Dorsal-fin rays (branched) | 15 | 15–17 | 14 |
Anal-fin rays (unbranched) | 3 | 3 | 3 |
Anal-fin rays (branched) | 16 | 15–17 | 16 |
Pectoral-fin rays (unbranched) | 1 | 1 | 1 |
Pectoral-fin rays (branched) | 16 | 11–15 | 12 |
Pelvic-fin rays (unbranched) | Broken | 1 | 1 |
Pelvic-fin rays (branched) | Broken | 6 | 6 |
Caudal-fin rays | 19 | 19 | 19 |
Gill rakers on 1st gill arch (upper) | 19 | 17–18 | 18 |
Gill rakers on 1st gill arch (lower) | 25 | 24–27 | 25 |
Gill rakers on 1st gill arch (total) | 44 | 42–45 | 42 |
Gill rakers on 2nd gill arch (upper) | 13 | 10–12 | 11 |
Gill rakers on 2nd gill arch (lower) | 20 | 20–23 | 22 |
Gill rakers on 2nd gill arch (total) | 33 | 30–35 | 33 |
Gill rakers on 3rd gill arch (upper) | 11 | 8–9 | 9 |
Gill rakers on 3rd gill arch (lower) | 11 | 11–13 | 12 |
Gill rakers on 3rd gill arch (total) | 22 | 20–22 | 21 |
Gill rakers on 4th gill arch (upper) | 9 | 6–7 | 7 |
Gill rakers on 4th gill arch (lower) | 9 | 9–10 | 9 |
Gill rakers on 4th gill arch (total) | 18 | 15–17 | 17 |
Gill rakers on posterior face of 3rd gill arch | 4 | 3–4 | 4 |
Prepelvic scutes | 7 | 6–7 | 7 |
Scale rows in longitudinal series | 38 | 36–38 | 38 |
Transverse scales | 8 | 8 | 8 |
Pseudobranchial filaments | Broken | 15–18 | 16 |
Total vertebrae | 42 | 41–42 | 42 |
Pectoral-fin rays with melanophores | 0 | 0 | 0 |
Character | Holotype | Non-types | Mean values |
---|---|---|---|
NTM S. 10031-153 | n = 9 | ||
Absolute values [mm] | |||
Standard length (SL) | 72.2 | 49.1–79.6 | |
Relative values (% SL) | |||
Head length | 22.6 | 21.6–22.9 | 22.2 |
Body depth | 19.7 | 17.4–20.9 | 19.4 |
Pre-dorsal fin length | 53.7 | 52.1–53.8 | 53.2 |
Snout tip to pectoral fin insertion | 23.5 | 21.9–26.0 | 23.5 |
Snout tip to pelvic fin insertion | 43.0 | 40.4–43.9 | 42.4 |
Snout tip to anal fin origin | 62.5 | 61.0–64.7 | 62.6 |
Dorsal fin base length | 14.8 | 13.3–14.3 | 13.9 |
Anal fin base length | 15.1 | 14.7–16.3 | 15.4 |
Caudal peduncle length | 24.8 | 21.2–23.4 | 22.7 |
Caudal peduncle depth | 9.1 | 8.0–8.9 | 8.6 |
D–P1 | — | 34.2–38.9 | 36.4 |
D–P2 | Broken | 21.1–24.4 | 22.8 |
D–A | — | 18.6–21.1 | 20.1 |
P1–P2 | Broken | 18.0–21.5 | 19.8 |
P2–A | Broken | 19.8–21.1 | 20.3 |
Pectoral fin length | 14.1 | 13.5–14.2 | 13.8 |
Pelvic fin length | Broken | 7.6–8.0 | 7.7 |
Maxilla length | 14.3 | 13.7–14.5 | 14.2 |
Mandibular length | 14.9 | 13.5–4.9 | 14.3 |
Supramaxilla end to maxilla end | — | 1.3–1.9 | 1.7 |
1st unbranched dorsal-fin ray length | 1.3 | 1.0–1.7 | 1.4 |
2nd unbranched dorsal-fin ray length | 6.8 | 5.7–7.1 | 6.5 |
3rd dorsal-fin ray length | Broken | 13.4–13.5 | 13.4 |
1st unbranched anal-fin ray length | Broken | 0.7–1.3 | 1.0 |
2nd unbranched anal-fin ray length | 4.9 | 4.0 | 4.5 |
3rd anal-fin ray length | Broken | Broken | |
Orbit diameter | 11.4 | 7.1–8.4 | 8.3 |
Eye diameter | 6.9 | 5.5–6.8 | 6.4 |
Snout length | 3.3 | 3.6–4.4 | 3.8 |
Interorbital width | — | 4.6–5.0 | 4.9 |
Postorbital length | 9.9 | 10.5–13.3 | 11.0 |
Body uniformly pale ivory or pale brown. Indistinct light brown longitudinal band narrower than eye running from opercle to caudal-fin base. Paired dark patches on parietal regions, but no melanophores on occipital area (a few melanophores in some specimens). No dark lines on dorsum. No melanophores on dorsal, pectoral, pelvic, and anal fins, and lateral surface of head. Melanophores scattered along caudal-fin rays. Fins pale, semi-transparent. Melanophores scattered on gill rakers, gill arch, gill filaments, inner side of hyoid, and pseudobranchial.
Stolephorus advenus has been recorded along the northern coast of Australia from Clarence Strait, Northern Territory to southern Gulf of Carpentaria (around Sydney Island, Queensland) (
Stolephorus advenus was described by
Specimens of Stolephorus advenus [A: holotype, NTM S. 10031-153, 72.2 mm SL, Cobourg Peinsula, Northern Territory, Australia (photograph taken by S. Tashiro); B: lateral, C: dorsal, and D: ventral views of non-type specimen, NTM S. 13803-003, 49.1 mm SL, Clarence Strait, Northern Territory, Australia (melanophores absent on occipital region); E: lateral view of whole body and F: dorsal view of head of non-type specimen, CSIRO CA 2688, 79.6 mm SL, Gulf of Carpentaria, Northern Territory (melanophores scattered on occipital region); scale bars indicate 0.5 mm].
Maxilla length (A), head length (B), body depth (C), pectoral-fin length (D), and pelvic-fin length (E) (all as % of standard length; SL) relative to SL in Stolephorus advenus (red circles), S. balinensis (blue triangles), S. belaerius (gray stars), S. commersonnii (purple hexagons), S. horizon (green squares), S. indicus (yellow diamonds), S. meteorum (dark blue inverted triangles), and S. scitulus (orange crosses).
Although the known distribution of the species was limited to the type locality (Cobourg Peninsula, Northern Territory, Australia), both
We are especially grateful to N. Bailly (BC), A. Suzumoto and L. O’Hara (BPBM), D. Catania and M. Hoang (CAS), A. Graham and J. Pogonoski (CSIRO), M. Nakae (NSMT), and B. Russell, M. Hammer, and G. Dally (NTM) for opportunities to examine specimens of Stolephorus. We also thank S. Tashiro (formerly KAUM), T. Clardy (LACM), and T. Munroe, K. Murphy, D. Pitassy, L. Willis, and A. Reft (USNM) for their curatorial assistance, and G. Hardy (Ngunguru, New Zealand), for checking an early version of the manuscript. This study was supported in part by the Sasakawa Scientific Research Grant from the Japan Science Society (28-745); a Grant-in-Aid from the Japan Society for the Promotion of Science for JSPS Fellows (DC2: 29-6652); JSPS KAKENHI Grant Numbers 19K23691; and JSPS Overseas Research Fellowships (202160519).