Apterichtus soyoae, Hibino, 2018
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publication ID |
https://doi.org/ 10.12782/specdiv.23.219 |
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publication LSID |
lsid:zoobank.org:pub:FA67D682-2B28-4161-9953-D6F01159151E |
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persistent identifier |
https://treatment.plazi.org/id/7B57E044-4540-40D5-A4BB-9DD9A9BCCAB9 |
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taxon LSID |
lsid:zoobank.org:act:7B57E044-4540-40D5-A4BB-9DD9A9BCCAB9 |
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treatment provided by |
Felipe |
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scientific name |
Apterichtus soyoae |
| status |
sp. nov. |
Apterichtus soyoae sp. nov.
[New Japanese name: Soyo-goma-umihebi] ( Figs 1–4 View Fig View Fig View Fig View Fig ; Table 1)
Holotype. NSMT-P 127390, 171 mm TL, sex unknown, off Tori-shima island , Zunan Islands, Izu Islands, southern Japan, depth 130 m, R / V Soyo-maru, collected by Takashi Okutani, 20 July 1979.
Diagnosis. An elongate species of Apterichtus with the following combination of characters: tail 1.8, head 12.6, and body depth 45.0 in total length (tail 57.0% TL, head 8.0% TL, and body depth at gill opening 2.2% TL); tip of lower jaw anterior to a vertical through anterior margin of eye; 3 preopercular and 5 supratemporal pores; teeth conical, uniserial on jaws, a single vomerine tooth; and VF 59-145.
Counts and measurements (in mm) of the holotype. Preanal vertebrae 59; total vertebrae 145; preanal lateral-line pores 59, with 8 pores in branchial region. Total length 171; head 13.6; trunk 59.9; tail 97.4; body depth at gill openings
3.8; body width at gill openings 2.5; body depth at anus 2.5; body width at anus 2.5; head depth at branchial basket 4.3; head width at branchial basket 3.8; snout length 2.4; tip of snout to tip of lower jaw 2.2; tip of snout to rictus (end of gape) 5.3; eye diameter 1.2; interorbital distance 1.1; gillopening length 2.0; isthmus width 0.5.
Description. Body elongate, subcylindrical, tip of tail strongly laterally compressed and extremely pointed ( Figs 1 View Fig , 2a View Fig ). Head short; preanal length much shorter than tail, 2.3 in TL.
Snout moderate in length, twice eye diameter, its tip prominently pointed; distinct median groove ventrally on snout, its anterior tip beyond anteriormost margin of first infraorbital pore; slope of dorsal surface of snout approxi- mately 40° relative to underside of snout. Anterior nostril tubular but extremely short, tube length shorter than pupil diameter; posterior nostril oval in shape with an inner valve, located on anteroventral margin of eye, opening ventrally. Eyes moderate in size, covered by a transparent skin; center of eye anterior to mid-jaw ( Fig. 2a View Fig ). Mouth inferior, distance from tip of snout to anterior tip of lower jaw slightly shorter than twice eye diameter; lower jaw short, its tip pointed and located anterior to a vertical through anterior margin of eye ( Fig. 3a View Fig ); rictus short, posterior end of gape well behind a vertical through posterior margin of eye; lips smooth with distinct folds, fold on upper lip extending from a vertical through first infraorbital pore to posterior rictus. Gill openings completely ventral, slender leaf-like shape, their diameters less than twice eye diameter; anterior margins of gill openings close-set but not connected.
Sensory pores on head developed, arrangement of those pores as follows ( Figs 2a View Fig , 4a View Fig ): 1+6 on supraorbital (5th pore branched downward from other pores), 6+3 on infraorbital, 5 on lower jaw, 3 on preopercle, and 5 on supratemporal, one of those on mid-temporal; a single median interorbital pore. Lateral-line pores small but obvious. Lateral line almost complete except for near tip of tail.
Teeth ( Fig. 2b, c View Fig ) pointed, slightly recurved posteriorly; teeth on maxilla and dentary uniserial; a single vomerine tooth on anteriormost vomer, clearly separated from upperjaw teeth; intermaxillary teeth slightly larger and more slen- der than maxillary teeth, arranged in a chevron shape along with edge of pre-ethmoid; part of intermaxillary teeth visible when mouth is closed. All fins absent.
Coloration. No fresh color information. In ethanol preservative, head and body mostly yellowish brown, with extremely faint pale brown spots on occipital.
Etymology. The scientific name soyoae after R/V Soyomaru, the collecting vessel of the holotype.
Distribution. Known only from the holotype, from off Tori-shima island, Zunan Islands of Izu Islands, southern Japan ( Fig. 5 View Fig ).
Remarks. Apterichtus soyoae sp. nov. is similar to A. moseri and A. klazingai in the numbers of its supratemporal and preopercular pores and vertebrae. In addition, the new species shares the location of the lower-jaw tip with A. moseri . Apterichtus soyoae differs from A. moseri in having more supraorbital pores (1+6 vs. 1+4), the number of branchings of the supraorbital canal (1 vs. 0), shape of the snout (distinctly pointed vs. relatively blunt), eye size (50% of snout length vs. 35–45%; 8.8% of head length vs. 6.3– 8.0%) ( Fig. 2a, c View Fig ), and the number of vomerine teeth (1 vs. 2–5). The new species can also be distinguished from A. klazingai by the number of branchings of the supraorbital canal (1 vs. 2) ( Fig. 4 View Fig ), the number of infraorbital pores (7 vs. 9), and location of the lower jaw tip (anterior to a vertical through anterior margin of eye vs. posterior to the vertical) ( Fig. 3a, b View Fig ).
In the genus, members having 1+4 supraorbital pores generally have no branchings in the supraorbital canal, and members having 1+6 supraorbital pores generally have two branchings of 4th and 5th supraorbital pores. However, in the latter group A. orientalis and A. soyoae have only one branching of the 5th pore. Additionally, A. australis and A. flavicaudus (Snyder, 1904) have 1+4 supraorbital pores but have one branching of the 4th pore ( Table 1). Although it is known that the numbers of the supratemporal and preopercular pores are nearly invariable within a species, two species ( A. jeffwilliamsi McCosker and Hibino, 2015 and A. moseri ) have intraspecific variation in that of the supratemporal and one of the preopercular pores. Intraspecific variations of the supraorbital counts were not observed by McCosker and Hibino (2015) or the present study. Consequently, the numbers of branching and supraorbital pore counts may contribute to species identification.
Comparative materials: Apterichtus hatookai : OMNH-P 13794 , holotype, 479 mm TL, Morode , Ainan , Minami-uwa , Ehime Prefecture, Shikoku Island , Japan; OMNH-P 13802 , paratype, 519 mm TL, Morode , Ainan, Mina Uwa , Ehime Prefecture, Shikoku Island, Japan . Apterichtus jeffwilliamsi: USNM 363869, holotype, 305 mm TL, Vanua Lava Island , Banks Islands , Vanuatu; USNM 427494 View Materials , 2 specimens, paratypes, 112–283 mm TL, collected with holotype; USNM 350117 View Materials , 2 specimens, paratypes, 149–178 mm TL, Ranon Bay, Ambrym Island, Vanuatu . Apterichtus klazingai: USNM 348474, 3 specimens, 148–198 mm TL, Dillon’s Bay , Erromango Island, Vanuatu; USNM 375002, 247 mm TL, Wallis Island, Ile Uvea . Apterichtus moseri: BSKU 65700, 395 mm TL, Tosa Bay (33°16.0′N, 133°37.4′E), 131–146 m; NSMT- P 104038, 498 mm TL, Kumano-nada Sea (34°15.96′N, 136°59.01′E), 111–114 m; NSMT-P 105671, 245 mm TL, Kii Peninsula (33°39.1′N, 135°6.4′E), 200 m; SNFR 11043, 420 mm TL, northern East China Sea; WMNH 2010 PIS 159, 448 mm TL, off Shirahama, Wakayama Prefecture, Japan GoogleMaps . Apterichtus nariculus: BPBM 38368, holotype, 308 mm TL, Laha (NW side of Ambon Bay), Ambon Island, Molucca Islands, Indonesia .
| R |
Departamento de Geologia, Universidad de Chile |
| V |
Royal British Columbia Museum - Herbarium |
| USNM |
Smithsonian Institution, National Museum of Natural History |
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.