Macrocephenchelys brevirostris ( Chen & Weng, 1967 )

Lin, James, Shao, Kwang-Tsao & Smith, David G., 2018, The eel genus Macrocephenchelys (Anguilliformes: Congridae) in Taiwan, with description of a new species, Zootaxa 4454 (1), pp. 186-199 : 192-194

Macrocephenchelys brevirostris ( Chen & Weng, 1967)

FIg. 3B , 4 , TABLe 1

Rhynchoconger brevirostris Chen & Weng, 1967:54 , Fig. 40 (type locality: Dong-gang [also spelled Tung-kang, same pronunciation], southWestern TaiWan). Lectotype: NMMBP 5177 (ex THUP 3078), designated by Ho et al. (2010:24); paralectotypes: NMMBP 4181 (ex THUP 0 3236 and 03241). Smith, 1989:512; Smith, 1999:1685, 1686.

Macrocephenchelys brevirostris ( Chen & Weng, 1967) : Smith, 2000:586; Karmovskaya, 2004:S24; Ho et al., 2010:23; Ho & Shao, 2011:24. Ho et al., 2015:148.

Material examined (49 SPeCIMeNS, 199–460 MM TL). Lectotype : NMMBP 5177 , (1, 320), DONg-gANg, PINgTUNg, TAIWAN, 1 AUg. 1965. Paralectotype : NMMBP 4181 (2, 282–293), DONg-gANg, 1 MAY 1966. Non-types : Daxi, Yilan, northeastern Taiwan : ASIZP 60186 (1, 460), 15 OCT. 1997; ASIZP 60316 (1, 199), 14 SeP. 1998; ASIZP 63752 (5, 296–455), 24.58°N, 122.10°E, 250 M, BeAM TRAWL, 26 AUg. 2003; TOU-AE 6752 (1, MATURe MALe, 450), TOU-AE 6753 (1, MATURe feMALe, 390), 16 OCT. 2012; TOU-AE 7046 (1, 417), 9 MAY 2012; USNM 441668 (1, 322), 27 MAR. 2004.

Nan-fang-au, Yilan, northeastern Taiwan: TOU-AE 6741 (1, MATURe feMALe, 450), TOU-AE 6742 (1, MATURe feMALe, 425), 14 FeB. 2012; TOU-AE 6901 (1, MATURe feMALe, 453), 19 OCT. 2012. Dong-gang, Pingtung , southwestern Taiwan : ASIZP 62152 (1, 268), 300 M, 28 JAN. 2001; ASIZP 64098 (2, 335–352), 22.19°N, 120.38°E , 23 NOV. 2001; ASIZP 65226 (1, 368), 28 APR. 2005; ASIZP UNCAT. (14, 225–367), 12 SeP. 2009; TOU- AE 6847 (1, MATURe MALe, 299), 4 FeB. 2013; USNM 399860 (1, 364), 8 NOV. 2009; USNM 400341 (1, 346), 8 NOV. 2009; USNM 437354 (7, 273–335), 6 NOV. 2015. Taiwan (no further data): USNM 396131 (1, 350), 2009; USNM 399951 (1, 230), 2009; USNM 400340 (1, 362), USNM 437353 (1, 235), 2015.

Diagnosis. Macrocephenchelys brevirostris IS DISTINgUISHeD fROM M. brachialis BY ITS MORe ROBUST BODY (DA 3.3–6.3 VS. 2.2–5.9%TL); gReATeR HeAD LeNgTH (10.5–13.9 VS. 7.1–9.5%TL); MORe ANTeRIOR DORSAL-fIN ORIgIN (OVeR TIP Of PeCTORAL fIN VS. WeLL BeHIND fIN); feWeR VeRTeBRAe (147–154 VS.173–183); 3 MANDIBULAR POReS (VS. 2); NO ST PORe (VS. 1); THe PReSeNCe Of fLeSHY PAPILLAe ON LOWeR jAW AND DORSALLY ON HeAD; SeNSORY PITS VeNTRALLY ON HeAD AND ABDOMeN; AND THe COLOR PATTeRN, gRAY ABOVe AND WHITe BeLOW. IT DIffeRS fROM M. soela BY THe MORe POSTeRIOR DORSALfIN ORIgIN (OVeR TIP Of PeCTORAL fIN VS. OVeR MIDDLe Of fIN; CASTLe, 1990). IT DIffeRS fROM M. nigriventris sp. nov. BY THe UNPIgMeNTeD BeLLY (VS. A CONSPICUOUS PATCH Of MeLANOPHOReS), A gReATeR AVeRAge PReANAL LeNgTH (27.1–33.5 VS. 24.4–28.0 %TL), MORe PRe-ANAL LATeRAL-LINe POReS (25–32 VS. 19–24), 3 MANDIBULAR POReS (VS 2), AND MORe TOTAL VeRTeBRAe (147–154 VS. 125–135).

Description. MeASUReMeNTS IN % TL: PAL 27.1–33.5, TAIL 67.9–72.1, TR 14.4–20.6, PDL 15.9–19.7, HL 10.5–13.9, DA 3.3–6.3. IN % PAL: TR 52.4–66.2 %, PDL 51.9–65.7, HL 35.8–47.6. IN % HL: S 15.7 –24.9, E 8.7 –15.3, IO W9.4 –23.1, UJ 18.9–35.7, LJ 16.3–24.4, GO 7.4–13.6, IB 25.3–39.7, PL 40.6–68.4. POReS: PGLL 5–7, PDLL 11–13, PALL 25–32, SO 3, IO 4+1+0, POM 6 (3+3), ST 0. FIN RAYS: PADR 30–44, PR 10–15. VeRTeBRAe: PDV 12–15, PAV 27–32, PCV 40–46, TV 147–154.

BODY MODeRATe, DORSAL-fIN ORIgIN OVeR TIP Of PeCTORAL fIN. SMALL fLeSHY PAPILLAe ON UNDeRSIDe Of SNOUT, BeHIND ANTeRIOR NOSTRIL, ALONg UPPeR jAW TO gILL-OPeNINg, MORe ABUNDANT ON SURfACe Of CHIN. SCATTeReD SMALL PIT-LIKe STRUCTUReS VeNTRALLY ON HeAD AND ABDOMeN, PReSUMABLY SeNSORY IN NATURe, STARTINg fROM LeVeL Of fIRST LATeRAL-LINe PORe, 8 ROWS fROM VeNTRAL VIeW ON ABDOMeN, AND 4 ROWS ON eACH SIDe, APPROxIMATeLY 70 SeNSORY PITS BefORe ANUS ON INNeRMOST ROW (THe MOST VeNTRAL SIDe).

MAxILLARY AND DeNTARY TeeTH SMALL, CONICAL, IN SeVeRAL IRRegULAR ROWS, WIDeR AT ANTeRIOR eND; INTeRMAxILLARY TeeTH CONICAL, SOMeWHAT LARgeR THAN MAxILLARY AND DeNTARY TeeTH, IN ABOUT 2 TRANSVeRSe ROWS; VOMeRINe TeeTH IN AN OVAL PATCH, SMALL AND CONICAL AT ANTeRIOR eND, LARgeR AND MOLARIfORM IN MIDDLe AND POSTeRIOR PART, exTeNDINg ABOUT HALfWAY TO eND Of MAxILLARY TOOTH ROW.

DISTINCTLY BICOLOReD, gRAY ABOVe AND WHITe BeLOW, WITHOUT A PATCH Of MeLANOPHOReS VeNTRALLY IN fRONT Of ANUS; fINS WITH WHITe MARgIN; gILL CAVITY BLACK.

MAxIMUM SIze ABOUT 500 MM TL.

Remarks. Macrocephenchelys brevirostris AND M. nigriventris ReSeMBLe eACH OTHeR AND ARe CLeARLY DISTINgUISHeD fROM M. brachialis BY THe MORe ROBUST BODY AND HeAD, MORe ANTeRIOR DORSAL-fIN ORIgIN, AND THe PReSeNCe Of fLeSHY PAPILLAe ON THe HeAD AND SMALL SeNSORY PITS ON THe UNDeRSIDe Of THe BODY.

Distribution. COMMON AROUND TAIWAN, APPAReNTLY IN SHALLOWeR WATeR THAN M. brachialis . THe TYPe LOCALITY IS DONg-gANg IN SW TAIWAN; IT IS ALSO COLLeCTeD AT DA-xI AND NANfANgAO IN NE TAIWAN. THe DISTRIBUTION BeYOND TAIWAN IS UNCeRTAIN. IT HAS BeeN RePORTeD fROM THe PHILIPPINeS, AUSTRALIA, AND NeW CALeDONIA, ( KARMOVSKAYA, 2004), BUT IT IS NOT CLeAR WHeTHeR THeSe ALL BeLONg TO THe SAMe SPeCIeS. FURTHeR STUDIeS ARe NeeDeD TO DeTeRMINe HOW MANY SPeCIeS ARe PReSeNT AND WHAT THeIR DISTRIBUTIONS ARe.

Figures

FIGURE 3. Head and anterior body With pores of three species of Macrocephenchelys. A. M. brachialis. B. M. brevirostris. C. M. nigriventris sp. nov.

FIGURE 4. Macrocephenchelys brevirostris. A. USNM 439072, 330 mm TL, lateral vieW. B. TOU-AE6847, 299 mm TL, head and anterior body in dorsal, lateral, and ventral vieW.