Chaunax hollemani, Ho, Hsuan-Ching & Ma, Wen-Chun, 2016

Ho, Hsuan-Ching & Ma, Wen-Chun, 2016, Revision of southern African species of the anglerfish genus Chaunax (Lophiiformes: Chaunacidae), with descriptions of three new species, Zootaxa 4144 (2), pp. 175-194 : 187-188

Chaunax hollemani sp. nov.

New English name: Holleman's frogmouth Figures 5 A–C; Tables 1–3

Holotype. MNHN 1977-0034 (1, 195), 18° 54'S, 43°55'1.2"E, 280–320 m, 24 Nov. 1973.

Paratypes. 4 specimens, 115-179 mm SL. MNHN 1977-0028 (2, 115–158), 23°19'58.8"S, 43°31'1.2"E, 350 m, Mar. 1969. MNHN 1977-0038 (2, 121–179), 12°52'1.2"S, 48°10'1.2"E, 428 m, Mar. 1971.

Diagnosis. A member of the C. fimbriatus -species group with following combination of characters: uniformly creamy white when preserved; pre-preopercle length 26.8–28.5% SL, head width 16.0–18.5% SL, post-anus length 28.9–31.8% SL; peritoneal membrane uniformly brown; 2 neuromasts in upper preopercular series, 11–14 in pectoral series, 33–38 in lateral-line proper; 9 rakers on second gill arch; and 12 or 13 pectoral-fin rays.

Description. Morphometric and meristic data are given in Tables 1–3; following data summary is provided for holotype and range in all types (if different) in parentheses. Dorsal-fin rays III, 12 (12 or 13, 1 with 13); pectoralfin rays 12 (12 or 13); anal-fin rays 7; caudal-fin rays 9. Head length 2.5 (2.5–2.6) in SL; head width 5.8 (5.4–6.2) in SL, 2.3 (2.2–2.5) in HL; pre-dorsal length 2.1 (2.0–2.2) in SL; pre-gill opening length 1.6 (1.6) in SL; prepreopercular length 3.7 (3.5–3.7) in SL, 1.5 (1.4–1.5) in HL; upper jaw 4.6 (4.3–4.8) in SL, 1.9 (1.8–1.9) in HL; illicial length 8.8 (7.2–9.4) in HL; eye diameter 5.3 (4.7–5.4) in HL; post-dorsal-fin length 6.3 (5.1–6.6) in SL, 2.5 (2.0–2.7) in HL; post-anus length 3.5 (3.1–3.5) in SL, 1.4 (1.2–1.4) in HL; post-anal-fin length 6.9 (6.3–7.3) in SL, 2.8 (2.5–2.9) in HL; caudal peduncle depth 4.8 (4.4–4.8) in HL; caudal-fin length 3.6 (3.2–3.6) in SL, 1.5 (1.2–1.5) in HL.

Head globular, skull elevated above rest of body posteriorly; trunk and tail robust, weakly compressed, tapering posteriorly to caudal-fin base; ventral surface of belly flattened; skin thick, loose and flaccid; interspace between eyes broad, flat; caudal peduncle short. Eyes oval, directed laterally to dorsolaterally; covered by dermal membrane, broadly connected to adjacent skin, forming clear window.

Illicium long, length subequal to eye diameter; esca depressed, forming large central plate bearing many thin brown cirri; second dorsal-fin spine close to illicium, embedded under skin and not detectable externally; third dorsal-fin spine situated at about midpoint of pre-dorsal distance, embedded beneath skin. Illicial trough long oval, narrow anteriorly and much broader posteriorly, slightly concave, its length about 1.5 times its width. Origin of soft dorsal fin slightly behind midpoint of body; pectoral fin emerging laterally near midpoint of body, slightly anterior to vertical through gill opening; pelvic fin on breast, well anterior to pectoral fin; anus situated at posterior fourth of body; anal-fin origin at posterior fifth of body, its tip well short of caudal-fin base when depressed.

Nostrils anterior to eye; anterior nostril surrounded by fleshy membrane, its rim taller posteriorly than anteriorly; posterior nostril a circular depression; mouth wide, superior, its opening nearly vertical; lower jaw robust, protruding slightly in front of upper jaw; maxilla tapering, narrow dorsally, broadly expanded ventrally; blunt symphysial spine on symphysis of lower jaw. Upper jaw with band of 6 rows of teeth and lower jaw with 5 rows, gradually narrowing posteriorly.

Narrow membrane on first gill arch; first ceratobranchial well-connected to opercular wall and first epibranchial entirely free of it; gill filaments present on second to fourth gill arches, two rows of gill filaments in second and third gill arches, single row of gill filaments on fourth gill arch; filaments on inner rows of third and fourth gill arches about two-thirds length of filaments on other arches; inner surface of fourth gill arch completely connected to body. Single row of 13 (13–15) rakers on 1st gill arch, 4 (4 or 5) on upper limb and 9 (9 or 10) on lower limb, 9 rakers on outer row of 2nd arch, 10 (9 or 10) rakers on outer row of 3rd arch, and single row of 8 (7 or 8) rakers on 4th arch.

Interspaces of lateral-line neuromast complex about equal to or slightly wider than width of neuromast; 3–6 (usually 3 or 4) pairs of short spines bridging each neuromast. Lateral-line neuromast counts: supraorbital (AB) 11; premaxillary (AC) 8; upper preopercular (BD) 2; infraorbital (CD) 6; lower preopercular (DG) 3; mandibular (EF) 6; hyomandibular (FG) 3; pectoral (GH) 12 (11–14, usually 12); anterior lateral-line proper (BB') 4 (4 or 5, usually 4); supratemporal (BB) 6; and lateral-line proper (BI) 33 or 34 (33–38), including 2 or 3 (usually 2) on caudal fin.

Dorsal surface covered by a few taller and stronger bifurcate spinules mixed with many simple, smaller spinules, except for eye window, lips, distal fifth of dorsal surface and entire ventral surface of pectoral fin, distal half of dorsal surface and entire ventral surface of pelvic fin, entire anal fin and its base, membranes of dorsal fin, anus, and caudal-fin rays. Broad band of 12 (10–14) rows of spinules in front of illicial trough. Ventral surface covered by shorter simple spinules. Jaws and body margin along lateral line densely covered with simple, stout cirri; entire dorsal surface covered by scattered simple cirri, relatively dense on supraocular membrane and lower portion of maxilla; cirri on dorsal surface and supraocular membrane accompanied by strong spinule, taller than those adjacent. Cirri absent from ventral surface.

Coloration. Fresh color unknown, presumably pinkish or reddish. When preserved, uniformly creamy white to light brown. Gill chamber pale, with large grayish patch on inner opercular wall; gill arches, buccal cavity, peritoneal membrane and external lining of stomach pale.

Size. Reaches at least 195 mm SL.

Distribution. Known from the western Indian Ocean off Madagascar ( Fig. 3 ) at depths 280– 428 m.

Etymology. The new species is named after Wouter Holleman, Research Associate at the South Africa Institute of Aquatic Biodiversity, in recognition of his contributions in fish taxonomy.

Figures

FIGURE 3. Distribution map of Chaunax atimovatae sp. nov. (red squares), Chaunax heemstraorum sp. nov. (green circles) and Chaunax hollemani sp. nov. (black star).

FIGURE 5. Chaunax hollemani sp. nov. A – B. MNHN 1977 - 34, holotype, 195 mm SL. B. 1977 - 0038, 1 of 2, paratype, 179 mm SL.