Four new species of the frogmouth genus Chaunax (Lophiiformes: Chaunacidae) from Taiwan and the Philippines Ho, Hsuan-Ching Ma, Wen-Chun Zootaxa 2022 2022-09-23 5189 1 146 179 Ho & Ma, 2022 Ho & Ma 2022 [151,408,1779,1806] Actinopterygii Chaunacidae Chaunax Animalia Lophiiformes 4 150 Chordata species albatrossae sp. nov.   Figs. 5, 6A; Tables 1‒4  urn:lsid:zoobank.org:act: 04839D32-DD22-42B8-868A-46FB5017D48C     Holotype. MNHN 2005-0517( 77.3 mmSL), ca. 13°38’N, 121°39’E, off Luzon Island, Philippines,  195–200 m,  1 Dec. 1973.   FIGURE 5.  Chaunax albatrossae  sp. nov., holotype, MNHN 2005-0517, 77.3 mm SL, preserved. A. Dorsal view. B. Lateral view. C. Mouth cavity.    Paratypes. Sevenspecimens, 59.3‒137.7 mmSL, all from Philippines:  MNHN 2005-0608( 2 specimens, 59.3– 93.5 mmSL), 12°19’58.8’’N, 121°42’0’’E, Tablas Strait, between Mindoro and Tablas Island,  673–675 m,  4 Jun. 1985;  MNHN 2005-0876(3, 44.9–119.2), 12°10’4.8’’N, 121°45’0’’E, Tablas Strait, between Mindoro and Tablas Island,  700–702 m,  4 Jun. 1985;  USNM 168872(1, 113.7), 8°34’48’’N, 124°1’22.8’’E, Iligen Bay, off Mindanao Island,  8 Aug. 1909;  USNM 168883(1, 137.7), 10°0’0’’N, 125°6’36’’E, Sogod Bay, off Leyte Island,  3‒1412 m,  31 Jul. 1909.   Etymology.This species is named after the vessel USFC Albatross, treated as feminine, in service with the United StatesBureau of Fisheries in the late 1800s and early 1900s, which collected the first two specimensof the present species.   Diagnosis.A small species (reaching 137.7 mmSL) of the  C. abeispecies group with dark gray mouth cavity and dark brown to black gill chamber and gill rakers; skin covered with short, simple spinules; lateral-line neuromasts BD 2–4 (mainly 3), GH 12–13, BI 28–33 (30–32); GRii 10–12 (11); eye large (9.6‒12.0% SL); head relatively long (42.4‒46.3% SL), pre-preopercular length 31.1‒32.1% SL, predorsal length 51.1‒53.0% SL, upper-jaw 25.0‒26.2% SL; peritoneum black; body in preserved state uniformly creamy-white, including esca.   Description.Morphometric (expressed as % SL) and meristic data are given in Tables 1‒4. Data for holotypeprovided below followed by ranges for paratypesin parentheses, when different. D III, 12; P 12 (11‒12, mainly 12); A 7; C 9. Lateral-line neuromasts: AB 11 (10‒11); AC 8; BD 3 (2–4); CD 6 (5–7, mainly 5‒6); DG 3; EF 6; FG 3; GH 12/13 (12‒13); BB 6; BB’ 4; BI 32/33 (28–33, mainly 30‒32), including 2/3 (2–4) on caudal fin. Gill rakers: GRi 4 +12 (10‒12)=16 (14–16); GRii 11 (10–12); GRiii 1+11 (10‒11)=12 (11 or 12); GRiv 10 (9‒10).   FIGURE 6.Dermal spinules of  Chaunaxspecies, SEM, all samples taken from skin above eye. A.  C. albatrossae  sp. nov., MNHN2005-0876, 119.2 mm SL. B.  C. apus, ASIZP64564, 154 mm SL. C.  C. abei, ASIZP70159, 137 mm. D.  C. breviradius, ASIZP70154, 76 mm SL.   TABLE 1.Frequency of pectoral-fin rays and lateral-line neuromasts (AB, AC, BD, CD, DG, EF, EG) of selected chaunacid species. Values are counted on both sides when available. *indicates the value of holotype.    Pectora-fin rays AB AC BD  n 10 11 12 13 14 n 10 11 12 n 7 8 9 n 2 3 4     C. abeigroup    C. abei 40 31 9* 56 5 48* 3 56 3 53* 56 53* 3    C. albatrossae  sp. nov. 16 5 11* 16 2 14* 16 16* 16 3 12* 1    C. apus 191 3 151 37 344 11 310* 23 342 3 338* 2 342 28 298* 16    C. breviradius 87 43 44* 95 3 92* 96 96* 96 92* 4     C. fimbriatusgroup    C. erythraeus  sp. nov. 6 6* 6 5* 1 6 6* 6 4* 2    C. fimbriatus 34 2 17 5 36 2 33 1 36 36 36 14 21 2    C. obscurus  sp. nov. 16 5* 11* 16 1 14* 1* 16 1 15* 16 16*    C. umbrinus 7 3 4 9 7 2 10 10 10 9 1    C. viridiretis  sp. nov. 18 18 18 16* 2 18 18* 18 16* 2     C. pictusgroup    C. penicillatus 84 41* 36 7 92 15 66* 11* 93 1 92* 93 83* 10*  CD DG EF FG  n 4 5 6 7 8 n 3 4 5 n 5 6 7 n 2 3 4     C. abeigroup    C. abei 56 18 35* 3* 57 57* 57 48* 9 57 57*    C. albatrossae  sp. nov. 16 6 8* 2 16 16* 16 16* 16 16*    C. apus 344 1 34* 267* 41 1 342 327 15* 343 12 317* 14 348 2 343* 3    C. breviradius 95 20 93* 2 96 96* 96 96* 96 96*     C. fimbriatusgroup    C. erythraeus  sp. nov. 6 5* 1 6 1 5* 6 6* 6 6*    C. fimbriatus 36 5 22 9 36 5 28 3 36 35 1 36 35 1    C. obscurus  sp. nov. 15 10* 4* 1 16 6 9* 1 14 14* 2 16 1 15*    C. umbrinus 10 4 6 10 8 2 10 1 9 10 10    C. viridiretis  sp. nov. 18 11 7 18 3* 13* 2 17 1 14* 2 18 18*     C. pictusgroup    C. penicillatus 94 2 48* 36 8 94 66* 24 4 94 93* 1 94 94* Head length 2.3 (2.2–2.4) in SL; head width 5.5 (5.3–5.7) in SL, 2.4 (2.3–2.4) in HL; predorsal length 1.9 (1.9– 2.0) in SL; pre-gill-opening length 1.6 (1.5–1.7) in SL; pre-preopercular length 3.2 (3.1–3.2) in SL, 1.4 (1.3–1.5) in HL; upper jaw 3.9 (3.8–4.0) in SL, 1.7 (1.7–1.8) in HL; illicial length 12.0 (11.8–12.6) in HL; pre-illicial length 13.8 (13.4–14.5) in HL; illicial trough length 6.4 (5.5–7.1) in HL; eye diameter 4.5 (4.2–4.8) in HL; post-anus length (TL1) 3.1 (2.8–3.2) in SL, 1.4 (1.3–1.4) in HL; post-dorsal length (TL2) 5.1 (4.9–5.2) in SL, 2.2 (2.1–2.3) in HL; post-anal length (TL3) 5.7 (5.3–6.5) in SL, 2.5 (2.3–2.8) in HL; caudal-peduncle height 5.2 (5.0–5.4) in HL; caudalfin length 3.4 (3.2–3.7) in SL, 1.5 (1.4–1.6) in HL. Body slender but head globular, skull slightly elevated posteriorly. Skin thin, loose and flaccid, semi-transparent. Pectoral- and pelvic-fin rays with free tips. Caudal peduncle relatively long and slender, slightly depressed, tapering posteriorly. Illicium short and stout, esca with large central tongue ( sensu Le Danois, 1978) bearing many thin cirri. Illicial trough broadly rounded or oval, flat, relatively short and broad, subequal in length to diameter of eye pupil. Interorbital space flat and broad.   TABLE 2.Frequency of lateral-line neuromasts (BB, BB’, GH, BI) of selected chaunacid species in present study. Values are counted on both sides when available. *indicates the value of holotype.    BB BB’ GH  n 5 6 7 n 3 4 5 6 n 9 10 11 12 13 14 15 16 17 18     C. abeigroup    C. abei 30 29* 1 57 57* 53 1 4 22 30* 6*    C. albatrossae  sp. nov. 8 8* 16 16* 16 9* 7*    C. apus 287 287 219 10 205* 4 241 3 16* 59 63 48 38 14    C. breviradius 48 1 47 95 7 88* 93 6* 20* 46 19 - 1 1     C. fimbriatusgroup    C. erythraeus  sp. nov. 3 3* 6 2* 4 6 5* 1    C. fimbriatus 18 18 36 6 29 1 36 3 16 14 3    C. obscurus  sp. nov. 8 6* 16 14* 1 1 16 3* 8* 5    C. umbrinus 5 1 3 1 9 1 8 10 1 5 3 1    C. viridiretis  sp. nov. 9 9* 18 8* 10 18 6* 7* 5     C. pictusgroup    C. penicillatus 30 30* 91 26 64* 1 90 10* 32* 36 10 2  BI  n 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44     C. abeigroup    C. abei 53 1 3 7 10 14 11* 4 3*    C. albatrossae  sp. nov. 16 1 1 5 6 2* 1*    C. apus 179 1 1 - 1 5 10 17 34 20* 20 24 18 14 9 5    C. breviradius 93 1 1 4 21* 26* 21 10 2 5 1     C. fimbriatusgroup    C. erythraeus  sp. nov. 6 2* 2* - 1 1    C. fimbriatus 34 2 3 5 2 14 3 3 2    C. obscurus  sp. nov. 15 1* 2 3* 2 2 1 1 1 2    C. umbrinus 8 1 2 3 2    C. viridiretis  sp. nov. 18 2 4* 4 6 1 1     C. pictusgroup    C. penicillatus 87 1 3 6 4 10 2 18 21* 7 12 2 - 1   FIGURE 7.Three nominal species in the  Chaunax abeispecies group. A.  C. apus, ASIZP63185, 185 mm SL, fresh. B.  C. abei, ASIZP63195, 130 mm SL, fresh. C.  C. abei, NMMB-P16429, 196.2 mm SL, preserved. D.  C. breviradius, NMMB-P22388, 87.6 mm SL, fresh. E.  C. breviradius, NMMB-P22388, 83.8 mm SL, preserved. Dermal spinules relatively short and thin, all straight and simple ( Fig. 6A); 4 or 5 rows of spinules in front of illicial trough; no spinules on illicial trough or illicial base; 3 or 4 pairs of spinules flanking lateral-line neuromasts. Teeth on both jaws slender, fang-like. Band of 6–7 irregular tooth rows on upper jaw, tooth length gradually increasing from outer to inner rows; 3–4 irregular rows of teeth on lower jaw, in same arrangement as on upper jaw. Teeth on vomer small, in approximately 3 irregular rows, separated into 2 patches by medial gap. Teeth on palatine small, in elongate patch close to outer end of corresponding vomerine patch.   TABLE 3.Gill raker counts of selected  Chaunaxspeciesin present study, all counted on one side only.    GRi GRii  n 11 12 13 14 15 16 17 n 8 9 10 11 12     C. abeigroup    C. abei 28 3 14 11* 28 24* 4    C. albatrossae  sp. nov. 8 2 2 4* 8 2 5* 1    C. apus 35 1 0 2 7 17 5 3 35 1 2 11 17 4    C. breviradius 40 6 18 16 40 27 13     C. fimbriatusgroup    C. erythraeus  sp. nov. 3 1* 2 3 1* 2    C. fimbriatus 18 4 9 5 18 14 4    C. obscurus  sp. nov. 8 1 3* 4 8 2 2* 4    C. umbrinus 5 3 2 5 1 3 1    C. viridiretis  sp. nov. 9 1* 3 3 2 9 5* 4     C. pictusgroup    C. penicillatus 38 4 11 19 4 38 12 23 3  GRiii GRiv     C. abeigroup  C. abei n 8 9 10 11 12 13 n 6 7 8 9 10    C. albatrossae  sp. nov. 28 16 10* 2 28 7 21*    C. apus 8 6 2* 8 7 1*    C. breviradius 35 7 21 5 2 35 1 5 27 2     C. fimbriatusgroup 28 2* 13 13 28 19* 8 1    C. erythraeus  sp. nov.    C. fimbriatus 3 1* 1 1 3 1* 2    C. obscurus  sp. nov. 16 4 9 3 18 8 10    C. umbrinus 8 4 4* 8 2 6*    C. viridiretis  sp. nov. 5 3 2 5 4 1     C. pictusgroup 9 7 2* 9 9*    C. penicillatus  38 4 21 13 38 29 9 Cirri present on surfaces of both jaws and lateral sides of body, mainly associated with lateral-line canals; no cirri on dorsal surface of head, supraocular membranes or lower part of maxilla.  Coloration.Fresh coloration unknown but presumably uniformly pinkish, with or without colored spots or patches. Preserved specimens light brownish without marks or spots; esca creamy-white, most cirri pale or brownish distally, but some uniformly brown on anterior surface; tongue and mouth cavity blackish (some paratypespaler than others following long-term preservation); gill chamber mostly blackish, paler on ventral surface; gill arches uniformly blackish, except rakers and filaments pale; peritoneum black.  Size.Attaining 137.7 mmSL (USNM 168883); apparently a small species.   Distribution. Typeseries collected from central Philippinesat depths of 195–702 m, excluding one specimen(USNM 168883) with imprecise depth record of 3‒1412 m. This species apparently rare in collections, possibly reflecting either low population size or restricted distribution.   Remarks.This new species is quite unusual in having a dark mouth cavity and gill chamber, something that is rare in chaunacids. Four other chaunacid species, three of them newly described below in the  C. fimbriatusspecies group, do possess this feature but can be easily separated from  C. albatrossaeby the cirri on the dorsal surface of their heads and other diagnostic characters given in their respective accounts. Another species  Chaunacops melanostomus, which has a uniformly dark brown body, also has dark mouth cavity and gill chamber. All the specimens comprising the typeseries of  C. albatrossaewere initially identified by us as  Chaunax apus Lloyd, 1909( Fig. 7A), a species that also occurs in the Philippines, because both species have a uniform, creamywhite color when preserved and they share similar proportions. But the new species differs from  C. apusin having a dark gray or dark brown mouth cavity and gill chamber (vs. uniformly pale); relatively short and fine, uniformly straight dermal spinules ( Fig. 6A; vs. slender and curved, Fig. 6B); GH 12‒13 (vs. 12–19, mainly 14–16); and BI 28‒33 (vs. 30‒43, mainly 37‒40).   Chaunax albatrossaeis likely sympatric with  C. breviradiusbut not with  C. abei. It has a relatively larger eye diameter, longer head, longer pre-opercular, predorsal and pre-gill opening lengths and longer upper-jaw length than either  C. abei( Figs. 7B, C) or  C. breviradius( Figs. 7D, E) from the South ChinaSea ( Table 4), as well as the other members of the  C. abeispecies group in the Indo-West Pacific region besides  C. apus(Ho, pers. data). Moreover,  C. albatrossaehas short, simple dermal spinules ( Fig. 6A), different from the mixture of bifurcate and simple spinules in  C. abei( Fig. 6C) but similar to those of  C. breviradius( Fig. 6D). 3914004322 1973-12-01 MNHN Philippines 198 13.633333 Luzon Island 1290 121.65 4 150 MNHN 2005-0517 1 holotype 3914004305 [199,987,1810,1837] Seven Philippines Philippines 5 151 1 paratype 3914004321 1985-06-04 MNHN Philippines 674 12.333 Tablas Strait 15 121.7 5 151 MNHN 2005-0608 2 paratype 3914004315 1985-06-04 MNHN Philippines 701 12.168 Tablas Strait 15 121.75 5 151 MNHN 2005-0876 1 paratype 3914004304 1909-08-08 USNM Philippines 8.58 Mindanao Island 15 124.023 Iligen Bay 5 151 USNM 168872 1 paratype 3914004314 1909-07-31 USNM Philippines 708 10.0 Island 21 125.11 Sogod Bay 5 151 USNM 168883 1 Southern Leyte paratype