Pycnocraspedum africanum, Schwarzhans & Psomadakis & Nielsen, 2025

Schwarzhans, Werner W., Psomadakis, Peter N. & Nielsen, Jørgen G., 2025, Revision of the bathydemersal fish genus Pycnocraspedum (Ophidiidae; Teleostei), with description of two new species, Zootaxa 5636 (3), pp. 443-472 : 453-455

Pycnocraspedum africanum sp. nov.

Figures 3 , 5 , 6 , 12 ; Tables 1, 2

Pycnocraspedum squamipinne (non Alcock, 1889): Schwarzhans 1994 (including holotype from MNHN), Fricke et al. 2018 (same specimens from MNHN including holotype and paratype), Nielsen & Uiblein (2022).

Pycnocraspedum sp. cf. squamipinne ? (non Alcock, 1889): Prokofiev (2005): 118, figs. 9–10 (same specimen from ZIN now paratype).

Material examined ( 7 specimens, 85–420 mm SL): Holotype: MNHN 2000–5691, 420 mm SL, 22°21'7.2''S, 43°4'4.8''E (off western Madagascar), beam trawl 450 m, Crosnier st. ch095, 27 November 1973; paratypes: MNHN 2000–5692, 330 mm SL, 12°27'7.2''S 48°12'3.6''E ( Madagascar Channel ), beam trawl 600–605 m, Crosnier st. ch021, 19 January 1972; 2 specimens SAIAB 98892 , 100–110 mm SL, 12.6953°S 40.667°E (off northern Mozambique), haul 135, beam trawl 292 m, 23 November 2007; 1 specimen SAIAB 98894 , 85 mm SL, 12.6953°S 40.667°E (off northern Mozambique), haul 136, beam trawl 391 m, 23 November 2007; 1 specimen SAIAB 98897 , 95 mm SL, 11.1341°S 40.7696°E (off northern Mozambique), 24 November 2007; 1 specimen, ZIN 51521, 210 mm SL, Vityaz cruise 17, st. 2522, 21°16'S 35°41'E (off eastern South Africa), 480–500 m, 21 November 1988.

Diagnosis. Precaudal vertebrae 12–13, total vertebrae 51–54; dorsal-fin rays 88–92; anal-fin rays 68–71; pectoral-fin rays 25; long gill rakers on first gill arch 4; pseudobranchials 4–5; 1–3 dorsal-fin rays in front of first vertebra; HL 27.1–27.6% of SL; body depth at vent 21–22.5% of SL; predorsal length 23–24.5% of SL; transversal scale rows above origin of anal fin 85–90, and above lateral line 22–23; broad expansion on preopercular angle with two spines, fleshy flap on hind margin of preopercle above spine 2; otoliths> 15 mm in length: OL:OH = 2.5–2.7, dorsal rim with rounded obtuse middorsal angle.

Description. Relatively robust fish with stout tapering tail and rounded snout.Maximal size of fishes investigated 420 mm SL (holotype). Preopercular rim with two blunt spines positioned at bend, fleshy flap above 2 nd spine and no spine further upward.

Meristics (6 specimens): precaudal vertebrae 13 (12–13); total vertebrae 53 (51–54); dorsal-fin rays 91 (88– 92); anal-fin rays 69 (68–71); pectoral-fin rays 25; caudal-fin rays 10; D/V = -2 (-1– -3); D/A = 28 (23–28); V/A = 19 (15–19); long gill rakers on first gill arch 4; pseudobranchial filaments 4 (4–5); transversal scale rows above origin of anal fin 85–90, and above lateral line 22–23; pyloric coeca unable to count.

Morphometrics (3 specimens) in % of SL: HL 27.1–27.6; body depth at vent 21 (21–22.5); diameter of eye 4.1 (4.1–4.8); upper jaw length 15 (12–15); interorbital width 7.1 (7.1–7.5); pelvic-fin base to anal-fin base 24 (24–26); predorsal length 24.5 (22.9–24.5); preanal length 52 (46.2–52); prepelvic length 27.5 (22.9–27.5); pectoral-fin length 13.5 (12–15.7); pelvic-fin length 12 (12–12.5).

Otolith morphology (4 specimens). Size up to 22 mm in length (holotype); OL:OH = 2.5–2.7 in specimens larger than 15 mm in length, 1.6 in specimens smaller than 7 mm in length, and single intermediate form with 2.3 at about 12 mm in length; OH:OT = 2.7–3.0. Thin, oval, elongated, anteriorly moderately projecting, posteriorly distinctly pointed, anterior and posterior tips inferior. Dorsal rim with broad, rounded, obtuse mediodorsal angle in large specimens and shallow ventral rim. All rims smooth in large specimens (> 15 mm in length) intensely crenulated in smaller specimens (<12 mm in length). Inner face slightly bent in horizontal direction, nearly flat in vertical direction, with very long, undivided sulcus reaching close to anterior and posterior rims of otolith. Sulcus with shallow, undivided, uniform colliculum with flat to slightly concave dorsal rim and slightly convex ventral rim and rounded anterior and posterior tips. OL:CL = 1.3–1.35. Dorsal field with broad, indistinct depression; ventral field smooth, occasionally with faint central furrow. Outer face smooth in large specimens, with many radial furrows and central tubercles in small specimens.

Coloration. Live coloration unknown. Color of preserved specimens light brown.

Discussion. Pyconocraspedum africanum is the largest species of the genus so far known, with the holotype of 420 mm of SL. The species differs from the type species Pycnocraspedum squamipinne in the higher number of anal-fin rays (68–71 vs. 57–65), the higher number of pseudobranchial filaments (4–5 vs. 1–2), the more slender shape (depth at vent in % of SL 21–22 vs. 17–18) and the shorter head (27.1–27.6 vs. 29.6–31.5 % of SL). Pycnocraspedum africanum differs from P. fulvum in the higher number of dorsal-fin rays (88–92 vs. 78) and anal-fin rays (68–71 vs. 63). Pycnocraspedum africanum differs from P. armatum and P. phyllosoma in the lower number of dorsal-fin rays (88–92 vs. 95–103). Pycnocraspedum africanum resembles closest P. rowleyensis sp. nov. from off northern Western Australia in the number of dorsal-fin rays and the presence of only 2 spines on the hind margin of the preopercle, but differs in the lower number of transversal scale rows (85–90 vs. 70), scale rows above the lateral line (22–23 vs. 17), the presence of a flashy flap above the lower preopercular spines (vs. concave section) and the more elongate otoliths (OL:OH = 2.5–2.7 vs. 2.1). Pycnocraspedum africanum differs from all other Pycnocraspedum species in the high number of transversal scale rows above the origin of the anal fin of 85–90 (vs. 52–78). The otoliths of P. africanum are slenderer than those of P. armatum and P. phyllosoma (OL:OH = 2.5–2.7 vs. 2.0–2.3) and are less strongly bent; and they differ from those of P. squamipinne in the long sulcus (OL:CL = 1.3–1.35 vs. 1.5–1.6). The otoliths of P. africanum are similar to those of the fossil P. cetonanense ( Schwarzhans, 1978) differing mainly in the narrower sulcus and the single, undivided colliculum (vs. two separate colliculi).

The specimens here selected as holotype and one of the paratypes from MNHN have previously been listed by Fricke et al. (2018) as P. squamipinne . Another specimen here listed as paratype from ZIN has been tentatively attributed to P. squamipinne by Prokofiev (2005). He noticed certain differences from typical P. squamipinne specimens such as the presence of 4 pseudobranchial filaments (vs. 1–2) and a more compressed, shorter head. It is possible that a large specimen recorded by Teena et al. (2021) from off Chennai coast, southern India, with a suspiciously high number of transversal scale rows could potentially represent P. africanum as well.

Distribution. Pycnocraspedum africanum is a relatively deep dwelling species at 450 to 605 mm depth, while all other species mostly occur between 300 and 500 m ( Nielsen et al. 1999). Pycnocraspedum africanum occurs off the East African coast from 11°S to 22°S, but could be more widely spread in the Indian Ocean subject to review of previously recorded specimens.

Etymology. Named after the continent of Africa from where the studied specimens have been obtained.

Figures

FIGURE 3. Detail figures and drawings of preopercular spines and lower preopercular pores in Pycnocraspedum; preopercular spines are numbered from 1 through 4 from the lower angle of the preoperculum upwards; abbreviation lpp = lower preopercular pore. 3A–3B) Pycnocraspedum armatum, USNM 227412, 3A1-3A2 specimen 1 left side, 3A3 specimen 1 right side (mirror imaged), 3B specimen 2; 3C–3D) Pycnocraspedum phyllosoma, 3C USNM 421587, 3D USNM 421586; 3E) Pycnocraspedum fulvum (holotype), BSKU 27497; 3F–3G) Pycnocraspedum africanum sp. nov., 3F holotype, MNHN 2000-5691, 3G paratype, MNHN 2000-5692; 3H) Pycnocraspedum rowleyensis sp. nov., holotype, WAM I.28059.021; 3I–3K) Pycnocraspedum squamipinne, 3I lectotype, BMNH 1890.7.31.1, 3J ZMUC P771871, 3K ZMUC P771737.

FIGURE 5. Otoliths, inner faces (if not noted otherwise) shown from right side. 5A–5C) Pycnocraspedum africanum sp. nov., 5A holotype, MNHN 2000-5691 (5A2 dorsal view), 5B paratype MNHN 2000-5692, 5C tentatively assigned specimen, IRSNB (5C2 dorsal view, 5C3 anterior view); 5D–5E) Pycnocraspedum armatum, 5D USNM 227412 (5D2 ventral view), 5E USNM 227390 (5E2 ventral view); 5F) Pycnocraspedum fulvum (holotype), BSKU 27497 (5F2 ventral view, 5F3 anterior view); 5G) Pycnocraspedum rowleyensis sp. nov., holotype, WAM I.28059.021 (5G2 ventral view); 5H) Pycnocraspedum phyllosoma, USNM 421587 (5H2 ventral view, 5H3 anterior view); 5I–5K) Pycnocraspedum squamipinne, 5I lectotype, BMNH 1890.7.31.1 (5I2 ventral view), 5J ZMUC P771871, 5L ZMUC P771739 (5L2 ventral view), 5K ZMUC P771738 (5K2 ventral view); 5M) †Pycnocraspedum cetonaense (holotype) SMF P.5694 (5M2 dorsal view, 5M3 anterior view).

FIGURE 6. Pycnocraspedum africanum sp. nov., holotype, MNHN 2000-5691, 420 mm SL, 22°21'7.2''S, 43°4'4.8''E, 450 m.

FIGURE 12. Geographic distribution of the species of Pycnocraspedum. One symbol can represent more than one location.