Moloha major ( Kubo, 1936 )

Ng, Peter K. L., Forges, Bertrand Richer De & Martin, Joel W., 2020, The Homolidae of the Hawaiian Islands, with notes on the taxonomy of Moloha major (Kubo, 1936) (Crustacea: Decapoda: Brachyura), Zootaxa 4809 (2), pp. 306-328 : 311-316

publication ID	https://doi.org/ 10.11646/zootaxa.4809.2.4
publication LSID	lsid:zoobank.org:pub:7DD95C27-8BEF-467A-B24F-B43C7665B1A9
persistent identifier	https://treatment.plazi.org/id/BF5DB417-DA5E-FFBE-FF38-F8C3218EDF76
treatment provided by	Plazi
scientific name	Moloha major ( Kubo, 1936 )
status

Treatment

Moloha major ( Kubo, 1936) View in CoL

( Figs. 2A, B View FIGURE 2 , 3–12 View FIGURE 3 View FIGURE 4 View FIGURE 5 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 )

Latreillopsis major Kubo, 1936: 63 View in CoL , pl. 17 (see Guinot & Richer de Forges 1995: 384; Richer de Forges & Ng 2007: 34; for complete synonymy up to 2008)

Paromala (sic) alcocki — Chave & Malahoff 1998: table 1 (not Latreillopsis alcocki Stebbing, 1920 View in CoL )

Moloha majora — Takeda & Manuel-Santos 2007: 90, fig. 9B.— Richer de Forges & Ng 2007: 34; Ng et al. 2008: 41; Wang et al. 2013: 1409; Ng & Richer de Forges 2017: 250 View Cited Treatment , fig. 24E; Wang et al. 2017: appendix 1; Ng et al. 2017: 28.

? Moloha alcocki View in CoL — Castro 2011: 35.

Material examined. Taiwan: 1 male (61.9 × 57.9 mm) ( ZRC 2008.1319 View Materials ), Tashi port, Ilan Province , coll. S.-H. Wu, 22 December 1997 .— 1 male (75.6 × 65.4 mm) ( ZRC 2001.0039 View Materials ), Tashi, Ilan Province , northeastern Taiwan, coll. K.-X. Lee, June 2000 . – 1 male (54.8 × 47.8 mm, broken) ( ZRC 2016.0197 View Materials ) (photograph), stn CP 4153, north of Macclesfield Bank, 16º13.94’N 114º27.21’E– 16º14.25’N 114º29.55’E, South China Sea , 318 m, sponge substrate with sea pens and echinoderms, trawl, coll. ZHONGSHA 2015 Cruise, 27 July 2015 GoogleMaps . Philippines: 3 males (77.6 × 67.9 mm, 31.5 × 27.7 mm, 19.2 × 18.4 mm) , 5 females (48.3 × 43.5 mm, 33.0 × 29.7 mm, 32.7 × 28.9 mm, 18.7 × 17.5 mm, 14.3 × 12.8 mm) ( ZRC 2007.0143 View Materials ), Balicasag, Panglao , Bohol, Visayas, 200–300 m, coll. tangle nets, local fishermen, June 2002 .— 2 males (72.5 × 65.4 mm, 62.2 × 55.3 mm), 1 female (46.8 × 41.0 mm) ( ZRC 2007.0145 View Materials ), Balicasag, Panglao, Bohol, Visayas , 100–500 m, coll. tangle nets, local fishermen, November 2003 – May 2004 .— 1 female (22.4 × 19.5 mm) ( ZRC 2001.0557 View Materials ), Balicasag, Panglao, Bohol, Visayas , coll. tangle nets, local fishermen, 28 November 2001 .— 1 male (65.3 × 57.6 mm) ( ZRC 2008.0751 View Materials ), Balicasag, Panglao, Bohol, Visayas , coll. tangle nets, local fishermen, 2000s . – 2 males (72.5 × 64.9 mm, 62.4 × 55.7 mm), 1 female (46.2 × 40.9 mm) ( ZRC 2007.0145 View Materials ), Balicasag, Panglao, Bohol, Visayas , coll. tangle nets, local fishermen, 29 November 2003 .— 1 male (79.3 × 70.1 mm), 1 female (60.5 × 52.3 mm) ( ZRC 2017.0799 View Materials ), Balicasag, Panglao, Bohol, Visayas , coll. tangle nets, J. Arbasto, 2006 .— 1 female (59.2 × 51.1 mm) ( ZRC 2011.0105 View Materials ), northwest coast of Panglao , Bohol, 146.3–548.6 m, coll. tangle nets, J. Arbasto, January–March 2011 .— 2 males (32.9 × 27.9 mm, 19.7 × 15.7 mm) ( ZRC 2009.0783 View Materials ), Bohol Sea , stn CP2343, 9°27.4’N– 123°49.4’E, 273–356 m, coll. PANGLAO 2005, 23 May 2005 GoogleMaps . – 1 soft (recently molted) female (38.4 × 34.6 mm) ( ZRC 2009.0784 View Materials ), Bohol Sea , stn CP 2372, 9°31.4’N– 124°00.6’E, 255–301 m, trawl, coll. PANGLAO 2005, 24 May 2005 GoogleMaps . Hawaiian Islands : 1 male (78.1 × 71.6 mm) (LACM-MBC-5564), reef slope, FFS-0065, DRS-5, BAIT-3, 23.703°N 166.339°W– 23.703°N 166.337°W, NWI, French Frigate Shoals, 95–130 m, baited trap, coll. R. Moffitt, K. Coontz, E. Soto, T. Lotufo, J. Martin, C. Pittman, A. Collins & S. Middleton, 15 October 2006 (photograph voucher JM0095 ) GoogleMaps .— 1 male (88.0 × 80.7 mm, missing left cheliped, P4 and P5) (LACM-MBC-5671), reef slope, FFS-0173, DRS-14, BAIT-2, 23.772°N 166.392°W– 23.774°N 166.395°W, NWI, French Frigate Shoals, 279–373 m, baited trap, coll. R. Moffitt, E. Soto, K. Coontz, J. Martin & C. Pittman, 24 October 2006 (photograph voucher JM0216 ) GoogleMaps .— 1 male (68.9 × 61.4 mm) (LACM- MBC-5601), reef slope, FFS-0103, DRS-8, BAIT-3, 23.903°N 166.3°W– 23.901°N, 166.3°W, NWI, French Frigate Shoals, 304–309 m, baited trap, coll. R. Moffitt, J. Martin, C. Pittman, G. Paulay, T. Lotufo, E. Soto & K. Coontz, 18 October 2006 (photograph voucher JM0151 ) GoogleMaps .— 1 male (60.3 × 52.4 mm) ( ZRC 2019.1109 View Materials ), reef slope, French Frigate Shoals , NWI, 23.740ºN 166.387ºW to 23.344ºN 166.381ºW, 180–250 m, in baited trap, coll. R. Moffitt, T. Lotufo, K. Coontz, L. Harris, E. Soto & C. Pittman, 11 October 2006 GoogleMaps (photograph voucher JM0043 ) .

Diagnosis. Large species (carapace length exceeding 50 mm). Carapace longitudinally subovate; covered by strong spines; gastric region separated from cardio-branchial regions by deep groove; cardiac region swollen, with 2 short spines; branchial region with several short spines; surface adjacent to intestinal region marked by 2 depressions forming “eye-like” structure in large male specimens, absent in females and smaller specimens; subhepatic region prominently inflated, with crown of 6 or 7 distinct spines, 2 anterior ones usually longest ( Figs. 4 View FIGURE 4 , 5 View FIGURE 5 , 6A, B, E, F View FIGURE 6 , 8A, C, D View FIGURE 8 , 10 View FIGURE 10 A–E). Rostrum with single, large spine; with 2 pseudorostral spines, directed upward, each with median accessory spine; 2 spinules at base of pseudorostral spines ( Figs. 5 View FIGURE 5 , 6A, B View FIGURE 6 , 8A, C View FIGURE 8 , 10A View FIGURE 10 ). Lateral margin of carapace delimitated by “homolian line” with 4 strong spines and 10 smaller spinules and sharp granules ( Figs. 5 View FIGURE 5 , 6A, B View FIGURE 6 , 8A View FIGURE 8 , 10A View FIGURE 10 ). Basal antennal article long, movable ( Figs. 6F View FIGURE 6 , 8D View FIGURE 8 ). Buccal cavity enlarged anteriorly with blunt spine on anterior corners ( Fig. 10G View FIGURE 10 ). Third maxilliped pediform; margin of merus flattened, denticulated ( Figs. 6C View FIGURE 6 , 8B View FIGURE 8 , 10F View FIGURE 10 ). Male chelipeds usually very long, strong, especially in large males, completely covered by strong granules and dense setae; distal border of coxa with strong blunt tooth, 1 strong curved spine on upper margin; merus with 4 strong spines on dorsal margin and 3 strong proximal spinules on ventral margin; carpus relatively long; chela elongated, inflated, covered with long setae; fingers crossing at tips when closed, dactylus with 1 proximal tooth ( Figs. 3 View FIGURE 3 , 4 View FIGURE 4 , 7E, F View FIGURE 7 , 9E View FIGURE 9 , 11A, B View FIGURE 11 ). Ambulatory legs very long; articles slender, long; P2 merus with 7 spines on dorsal margin and 7–16 spines on ventral margin; P3 merus with 6 spines on dorsal margin and 10–13 spines on ventral margin; P4 merus with 3–5 spines on dorsal margin and 10–14 spines on ventral margin; 3 spines present on P2–P4 basisischium; P 5 in dorsal position, merus long, reaching base of pseudorostral spines when positioned on carapace, with 1 strong curved distal spine, rest of dorsal margin entire or with 2 or 3 small spines; carpus curved; propodus very short, forming pseudochela with curved dactylus; ventral margin of propodus with distinct spines ( Figs. 3 View FIGURE 3 , 4 View FIGURE 4 , 7 View FIGURE 7 A–D, 9B–D, 11C–G). Pleon with 6 somites and telson, first 3 somites with strong median spine; telson triangular, tip sharp, proximal part of margins almost straight, subparallel ( Figs. 6D View FIGURE 6 , 9A View FIGURE 9 , 10G View FIGURE 10 ). G1 stout, distal half short in smaller males, elongated in large ones ( Fig. 12 View FIGURE 12 ).

Remarks. Chave & Malahoff (1998: table 1) recorded “ Moloha alcocki (Stebbing, 1920) ” from Hawai‘i, and while Castro (2011: 35) listed this species from the islands, he expressed his doubt about its identity as this species has only been reliably recorded from the Indian Ocean ( Guinot & Richer de Forges 1995). Ng & Kumar (2015) revised the taxonomy of the Indian Ocean species of Moloha including M. alcocki . One subspecies affiliated with M. alcocki had been described from the South China Sea, Paromola alcocki faughni Serène & Lohavanijaya, 1973 , but Ng (2015) showed that this was just a juvenile of P. macrochira Sakai, 1961 . The present two specimens from Hawai‘i suggest that in all likelihood the record of “ M. alcocki ” by Chave & Malahoff (1998) is actually M. major instead.

Moloha major was described (as Latreillopsis major ) from one male and one female collected off Kominato in Japan by Kubo (1936). The provenance of this material is not known and almost certainly be lost (see Ng & Richer de Forges 2015). Sakai (1936: 49) first transferred the species to another genus and cited it as “ Homola (Parhomola) majora ”. He did not explain why the species name was changed but he may have assumed that because the gender of Homola is feminine, the species name should be changed to “ majora ” to co-ordinate with it. All subsequent authors have spelled the species name as “ majora ” (see Guinot & Richer de Forges 1995: 384; Richer de Forges & Ng 2007: 34). This is incorrect as the Latin name “ major ” is both masculine and feminine.

The large series of specimens of M. major from Balicasag Island in the Philippines, with juveniles to very large males allows us to understand the variation within one species and how characters change with size ( Figs. 3–5 View FIGURE 3 View FIGURE 4 View FIGURE 5 ). For example, the rounded eye-like depressions on the intestinal region are absent or just visible in smaller males and adult females ( Fig. 5 View FIGURE 5 ), being present only in large males ( Figs. 6A, B View FIGURE 6 , 8A View FIGURE 8 , 10A View FIGURE 10 ). Interestingly, the pattern of spination on the carapace and pereopods remains essentially the same despite growth or sex, although the subhepatic spines, for example, are relatively shorter in adults ( Fig. 5 View FIGURE 5 ). The G1 structure must be used with care. Relatively smaller but adult males of M. major (ca. 60 mm in carapace length) have a G1 that is short and stout, with the distal part short ( Fig. 12A, B View FIGURE 12 ). In very large males of M. major , however, the G1 distal part is distinctly more elongate ( Fig. 12C View FIGURE 12 ).

Most of the specimens from the Philippines differ from those from Taiwan in a number of characters. In general, the carapaces of the Philippine specimens are proportionately shorter and more longitudinally ovate ( Figs. 5 View FIGURE 5 , 8A View FIGURE 8 ) compared to those from Taiwan ( Fig. 6A, B View FIGURE 6 ); the subhepatic region usually has seven (rarely six) distinct spines ( Fig. 8C View FIGURE 8 ) (six in Taiwan; Fig. 6E View FIGURE 6 ); the P2–P4 are also slightly more slender ( Figs. 3C View FIGURE 3 , 4 View FIGURE 4 , 9B View FIGURE 9 ) (slightly stouter in Taiwan; Figs. 3A, B View FIGURE 3 , 7A, B View FIGURE 7 ); the adult P2 merus usually has seven (sometimes eight or nine) spines on the ventral margin ( Fig. 3C View FIGURE 3 ) (10–17 in Taiwan; Fig. 3A, B View FIGURE 3 ); the adult P3 merus usually has 10 (sometimes 11) spines on the ventral margin ( Fig. 3C View FIGURE 3 ) (usually 12 or 13 in Taiwan; Fig. 3A, B View FIGURE 3 ); its adult P4 merus usually has three spines on the dorsal margin and usually has 10 or 11 spines on the ventral margin ( Figs. 9B View FIGURE 9 ) (six on the dorsal margin and usually 13 or 14 on the ventral margin in Taiwan; Figs. 7A, B View FIGURE 7 ); on the adult P5, there is a distinct spine on the coxa ( Fig. 9C View FIGURE 9 ) (with only a small spinule in Taiwan; Fig. 7C View FIGURE 7 ); the spines lining the ventral margin of the P5 propodus are relatively more slender ( Fig. 9D View FIGURE 9 ) (propodal spines relatively stouter in Taiwan; Fig. 7D View FIGURE 7 ); and the adult male cheliped has a slightly more elongated and inflated palm ( Fig. 9E View FIGURE 9 ) (shorter and stouter in Taiwan; Fig. 7E, F View FIGURE 7 ). The leg proportions, however, vary too much to be reliable. The number of spines is not always easy to discern as some spines are so low that they appear as small sharp granules. All in all, these characters are just not consistent and reliable enough to treat the Philippine material as a distinct species for the time being.

The two male specimens from Hawai‘i (LACM) are very similar to M. major but differ in three characters: the median surface of the subhepatic region only has a row of two spines ( Fig. 10D, E View FIGURE 10 ), the cardiac region has four distinct granules ( Fig. 10A View FIGURE 10 ), and the dorsal margin of the P5 merus sometimes has three small spines ( Fig. 11F View FIGURE 11 ). In all other aspects, they agree very well with the rest of the material from the Philippines and Taiwan. These three characters are not sufficient to distinguish them as a separate species for now. While most of the specimens of M. major from Taiwan and the Philippines have three spines on the median surface of the subhepatic region, a few have only two, so this feature can vary. Similarly, while the four granules on the cardiac region of the Hawaiian specimens are distinct, these granules do get more prominent with increasing carapace size in the Taiwan and Philippines material ( Figs. 6A, B View FIGURE 6 , 8A View FIGURE 8 ), with small specimens lacking them ( Fig. 5 View FIGURE 5 ). In one large specimen of M. major from Taiwan, the cardiac region has two distinct granules and two barely discernible very low ones as well ( Fig. 6B View FIGURE 6 ). Other large specimens, however, only have two visible granules ( Figs. 6A View FIGURE 6 , 8A View FIGURE 8 ). The armature on the P5 merus varies somewhat in these specimens. The P5 meri of the specimens of M. major from the Philippines and Taiwan are all unarmed, although they sometimes have very small granules which may be precursors of spines. In the smaller Hawaiian specimen (60.3 × 52.4 mm, ZRC 2019.1109), the left P5 merus has three small but distinct spines ( Fig. 11F View FIGURE 11 ) but on the right merus, these spines are absent and only small granules present. In life, the colour of the Hawaiian specimens of Moloha major are pale orange overall with the tips of the carapace spines red ( Fig. 2A, B View FIGURE 2 ). This differs somewhat from specimens from Japan, Taiwan and Philippines which are typically dark red overall (e.g., Ahyong et al. 2009: fig. 73).

Distribution. Japan, Taiwan, South China Sea, Philippines and Hawaiian Islands; 100–310 m (cf. Guinot & Richer de Forges 1995; Richer de Forges & Ng 2007; Ahyong et al. 2009).