Parabathymyrus brachyrhynchus ( Fowler, 1934 )

Ho, Hsuan-Ching, Smith, David G. & Shao, Kwang-Tsao, 2015, Notes on the congrid eel genus Parabathymyrus from the western Pacific Ocean, with the description of a new species (Pisces: Anguilliformes: Congridae), Zootaxa 4060 (1), pp. 131-139 : 134-137

Parabathymyrus brachyrhynchus ( Fowler, 1934)

Figs. 2 A–B; Tables 1–2

Arisoma [sic] brachyrhynchus Fowler, 1934:269 (Utara Pt., Bongo Island, Illana Bay, southern Mindanao Island, Philippines, 7°21’45”N, 124°07’15”E, depth 158 fathoms [289 m]).

Parabathymyrus brachyrhynchus ( Fowler, 1934) : Smith & Kanazawa, 1977:532. Smith, 1989:504. Smith, 1999:1686. Iwamoto & McCosker, 2014:272.

Parabathymyrus macrophthalmus (not of Kamohara, 1938): Chen & Weng, 1967:175. Shen, 1984:111. Chen & Yu, 1986:252. Shen et al. 1993:117. Shen & Wu, 2011:139.

Material examined (47, 186– 502 mm TL). Holotype: USNM 92357 (1, 327), Southern Mindanao, Eastern Illana Bay, Utara Point, Bongo Island, Philippines, 7°21'45"N, 124°07'15"E, 289 m, 22 May 1908. Paratype: USNM 135121 (1, 268), Gulf of Davao, Dumalag Island, 7°02'N, 125°38'4"E, 247 m, 18 May 1908, Albatross D.5247. Non-types: Taiwan: off Dong-gang, SW Taiwan, ca. 150–350 m: ASIZP 65130 (1, 383), 10 Mar. 2005. CSIRO H7398-12 (1, 457), 18 Mar. 2012. CSIRO H7419-07 (1, 376), 27 Dec. 2012. NMMB-P 1403 (1, 470), 4 Mar. 1965. NMMB-P 1412 (1, 405), 6 Feb. 1966. NMMB-P 2458 (1, 328), no date. NMMB-P 9079 (1, 430), 13 Jun. 2008. NMMB-P 9092 (1, 470), 13 Jun. 2008. NMMB-P 11167 (1, 345), 15 Dec. 2009. NMMB-P 11168 (1, 466), 15 Dec. 2009. NMMB-P 11169 (1, 424), 15 Dec. 2009. NMMB-P 11914 (3, 402–472), 26 Feb. 2011. NMMB-P 12175 (1, 428), 31 Dec. 2010. NMMB-P 13161 (1, 502), 12 Sep. 2009. NMMB-P 13674 (1, 351), 2 Jul. 2011. NMMB-P 14034 (1, 355), 3 Nov. 2011. NMMB-P 15391 (1, 420), no date. NMMB-P 15566 (1, 383), no date. NMMB-P 16437 (1, 407), 15 Jun. 2009. NMMB-P 17791 (1, 464), 9 Aug. 2012. NMMB-P 17868 (1, 392), 25 Jan. 2012. NMMB-P 17869 (1, 342), 25 Jan. 2012. USNM 398510 (1, 395), 12 Nov. 2009. USNM 400284 (1, 410), 25 May. 2010. USNM 395265 (1, 483), 16 May. 2008. Off Daxi, NE Taiwan: NMMB-P 15565 (2 of 3, 385–387), 23 Oct. 2011. Off Nan-fang-ao, Yilan, NE Taiwan: NMMB-P16195 (1, 317), 20 Jul. 2010. The Philippines: USNM 344105 (6, 320–364), Albay Gulf, Luzon, Philippines, 363–385 m, 23 Sep. 1995. Vietnam: NMMB-P 12330 (1, 361), Da Nang, 9 Apr. 2011. Vanuatu: MNHN 1997-0827 (3, 379–448), 15°7'1.2"S, 166°55'1.2"E, 262–352 m, 9 Sep. 1994. Solomon Islands: MNHN 2002-3850 (6, 186–340), 9° 21'3.6"S, 160°23'13.2"E, 357–359 m, 1 Oct. 2001. MNHN 2006-0079 (1, 343), 7°28'15.6"S, 156°18'25.2" E, 105 m, 2 Nov. 2004.

P. philippinensis sp. nov. P. brachyrhynchus P. macrophthalmus MVF 8-42-142 11-52-164 10-43-133

*Value of NMMB-P 11170.

Diagnosis. A species of Parabathymyrus with 4 supraorbital pores; head 5.5–6.7 in TL; 49–58 preanal vertebrae; 162–173 total vertebrae; 48–54 preanal LL pores; 159–169 total LL pores. Two rows of teeth on most of both jaws.

Description. Head length 5.5–6.7 times in TL; body depth at head 13.4–16.9; predorsal 4.9–6.4; preanal 2.3– 2.6; trunk length 3.6–4.4; tail length 1.6–1.8. Snout 5.4–7.6 times in HL; eye 4.8–6.5; interorbital 4.7–12.5; snoutrictus 2.9–4.2; gill opening 5.5–8.1; interbranchial 3.7–6.4; pectoral fin 2.1–3.4. Pectoral-fin rays 14–17.

Body relatively stout, depth of head not much larger than that of tail; head and trunk cylindrical, gradually compressed to caudal fin; trunk long; tail moderately long. Origin of dorsal fin above pectoral fin; original of anal fin slightly anterior to middle of total length; snout short and obtuse.

Eye relatively large, above posterior half of upper jaw and its posterior margin slightly behind level of rictus; interorbital space broad; gill opening moderately high, in front of pectoral fin and extended to middle of pectoralfin base. Anterior nostril tube-like, at front of snout; posterior nostril large, just above the upper jaw, covered by a large flap dorsally.

Mouth moderately large, its opening slightly oblique, rictus extends to posterior one-third of orbit; upper jaw protrudes anterior to lower jaw; upper labial flange well developed, extending from anterior nostril to two-thirds of upper-jaw length; lower jaw with a deep fold from tip to rictus; pectoral fin narrow and pointed.

Teeth small and villiform; intermaxilla with 4 rows of teeth forming a rounded patch, exposed when mouth closed; vomerine teeth a small triangular patch closely attached to that of intermaxilla; both jaws with 4–6 rows of teeth on anterior part and 1–2 rows on most of the remainder.

Vertebrae: predorsal 8–13, preanal 49–58, total 158–173 and mean vertebral formula (MVF) 11-52-164. Lateral-line pores moderate in size and complete, prepectoral 7–10, predorsal 8–11, preanal 46–54 and total 158– 169. Head pores: SO 4, IO 5, POM 10–12, ST 0, F 0, AD 0.

Coloration. When fresh, pinkish brown or yellowish brown dorsally, paler ventrally, pectoral fins reddish to grayish, anterior part of median fins yellowish or pinkish, with black margin in posterior portion. When preserved, brownish gray dorsally and paler ventrally, pectoral fin white, anterior part of median fins pale, with black margins in posterior portion, mouth cavity, gill chamber and peritoneum white.

Distribution. Known only from the western Pacific off Taiwan, Vietnam, the Philippines, Vanuatu and Solomon Islands. Bathymetric range 105– 385 m.

Remarks. Smith (1994) reported 19 predorsal vertebrae for the holotype of P. brachyrhynchus , whereas all specimens we examined have 8–13 (n=38) predorsal vertebrae. We also found a specimen of P. macrophthalmus that has relatively more predorsal vertebrae (15, vs. 9–13 in other specimens, n=46). The relatively more predorsal vertebrae in these specimens of P. brachyrhynchus and P. macrophthalmus is apparently anomalous.

Karmovskaya (2004) separated P. fijiensis from P. brachyrhynchus by having relatively more total vertebrae (173 vs. 166–168), fewer preanal pores (47 vs. 50–52), and its dorsal-fin origin above the pectoral-fin base (vs. dorsal-fin origin slightly behind middle of pectoral fin). The holotype of P. fijiensis has 50 preanal pores and 167 total pores (HH's examination). We also examined a large number of P. brachyrhynchus and found that the data for the holotype of P. fijiensis mostly fall within the range of P. brachyrhynchus ( Tables 1–2 ). More specimens of P. fijiensis are needed to understand the variation of this species and whether it and P. brachyrhynchus are conspecific.

HH examined three specimens from Vanuatu and seven specimens from the Solomon Islands. All these specimens are identical to those of P. brachyrhynchus that we examined. Thus they are identified as P. brachyrhynchus rather than P. fijiensis .

It is also notable that the holotype of P. fijiensis does not have a black anal-fin margin, whereas all specimens of P. brachyrhynchus have a black margin on their anal fin and those from Vanuatu and the Solomons have a slightly broader black margin than those from the NW Pacific Ocean.

Figures

FIGURE 2. Parabathymyrus brachyrhynchus (Fowler, 1934). A. NMMB-P 12175, 428 mm TL. NMMB-P 11914, 1 of 3, 402 mm TL. Both collected from Dong-gang, SW Taiwan.