Lampris megalopsis, Underkoffler & Luers & Hyde & Craig, 2018

Underkoffler, Karen E., Luers, Meagan A., Hyde, John R. & Craig, Matthew T., 2018, A taxonomic review of Lampris guttatus (Brünnich 1788) (Lampridiformes; Lampridae) with descriptions of three new species, Zootaxa 4413 (3), pp. 551-565 : 561-563

Lampris megalopsis , n. sp.

urn:lsid:zoobank.org:act:800A3E1C-F96A-4C63-A29C-223AAF383C4D Fig. 4F

Lampris guttatus (Brünnich 1778)

Lampris guttatus Lineage 3. Hyde et al. 2014.

Common Name: Bigeye Pacific Opah

Holotype. USNM 402733, Female, 85.3 SL, 40.8 kg, 23°–26° N, 140°–155° W, March 24, 2009, Longline, COI “Lineage 3” ( Hyde et al. 2014) GenBank accession # JF931871

Paratype. USNM 402734, Female, 73.4 SL, 23.1 kg, 24°–30° N, 147°–153° W, April 4, 2009, Longline, Underkoffler and Sundberg, GenBank accession # JF931871

Diagnosis. A species of Lampris distinguished from other members of the genus by the following combination of characters: dorsal rays I,50; anal rays 38; pectoral rays 23; pelvic rays 15; tongue generally purple; horizontal eye diameter greater than 30% HL; dorsal-fin height on average 26.3% FL; pelvic-fin length on average 33.6% FL; caudal fin uniformly pigmented.

Description. Dorsal-fin rays I,51 (I,50–51); anal-fin rays 38 (38); pectoral-fin rays 23 (22–23); pelvic-fin rays 15 (14–15). Body laterally compressed and rounded, its greatest depth contained 1.5 times in standard length; head length contained 2.8 (2.8) times in standard length; vertical eye diameter contained 4.7 (4.5–4.7) times in head length; jaws protractible and lacking teeth; upper jaw shorter than lower jaw; lower jaw protrudes slightly forward of upper jaw, the tip narrowing to a blunt point; throat and palate without teeth. Lateral line angled above gill opening, arching above pectoral fins, and extending along mid-height of body through center of caudal peduncle. Scales small, thin, and easily removed over entire body. Dorsal fin comparatively short, the length of its base contained 1.8 (1.8) times in standard length, its height contained 3.2 (2.7–3.2) in standard length. Origin of pelvic fin below or anterior to middle of elongated portion of dorsal fin, its length contained 2.5 (2.5) times in SL.

Distribution. Lampris megalopsis is a cosmopolitan species and has been recorded from the Central-North Pacific west to American Samoa, Australia and Indonesia, South Africa (Indian Ocean), the Gulf of Mexico, and along the Chilean coastline. However, based on the frequency of occurrence of this species in> 500 DNA samples, L. megalopsis is only rarely found east of 160°W.

Etymology. The specific epithet is taken from the Greek mega, meaning, “big or large”, and ops meaning “eye” in reference to its comparatively large eye.

Coloration. In dead specimens (unpreserved), body steel grey on dorsal surface fading to bright silver on ventral surface. Irregular white spots distributed over entire body, head, and chest. Fins deep red. In preserved specimens, body dark grey with spots and median fins appearing yellowish tan.

Remarks. Lampris megalopsis is very similar to L. incognitus with which it shares a small portion of its range. The most obvious difference is in the size of the eye. In L. megalopsis , the horizontal eye diameter is typically> 5.0 % FL and is contained ~4.7 times in head length. In L. incognitus , the horizontal eye diameter is typically <5.0 % FL and vertical eye diameter is contained ~5.4 times in head length.

Figures

FIGURE4. Species of the genus Lampris. A) Lampris immaculatus*, B)Lampris guttatus, uncatalogued, 118 cm TL †, C) AM I.24492-001, holotype, Lampris australensis n. sp. 67.3 cm SL, D) MMF 42253, Lampris lauta, 90.5 cm SL, E) USNM 402733, holotype, Lamprismegalopsisn. sp., 85.3 cm SL, F) USNM 402731, holotype, Lampris incognitusn. sp., 82.8 cm SL. (*Photograph by Dianne J. Bray, Lampris immaculatus in Fishes of Australia, accessed 17 Feb 2018, http:// fishesofaustralia.net.au/home/species/1503)(† Photograph courtesy of Patrice Francour).