Minutomon, Huang, Chao, Mao, Si Ying & Huang, Jian Rong, 2014

Huang, Chao, Mao, Si Ying & Huang, Jian Rong, 2014, Two new potamid crabs, Yuexipotamon arcophallus new genus, new species and Minutomon shanweiense new genus, new species, (Crustacea: Decapoda: Brachyura: Potamidae) from southern China, Zootaxa 3764 (4), pp. 455-466 : 461

Minutomon , new genus

Diagnosis. Carapace with dorsal surface slightly convex; surface generally covered with weak rugae on anterolateral regions ( Fig. 7 A); postorbital cristae blunt, expanding to epigastric cristae and anterolateral margin ( Fig. 7 A); external orbital tooth bluntly triangular with convex margins, separated from anterolateral margin by gap ( Fig. 7 A,C); median lobe of posterior margin of epistome broadly triangular ( Fig. 7 C); third maxilliped with slender ischium, exopod reaches beyond ischial margin, with long flagellum ( Fig. 8 D); male abdomen triangular, telson with almost straight lateral margins, rounded tip ( Fig. 7 B); G1 slender, straight, terminal segment rugose, bent outwards ( Fig. 7 D, 8B, C); basal segment of G2 subquadrate ( Fig. 8 A).

Etymology. The genus name is derived from the Latin word for small, minutus, which describes the small size of the type species for this genus. The suffix “-mon” is derived from Potamon , the type genus of the family. Gender of genus neuter.

Remarks. Sinopotamon and Mediapotamon are similar to Minutomon , new genus, but the three genera can easily be distinguished by a number of characters ( Table 2 ). The G1 of Minutomon shanweiense , new genus, new species, and Sinopotamon kwanhsiense Tai & Sung, 1975 , are similar, but this may be due to convergent evolution because all their other characters are very different. The references to some characters of Sinopotamon and Mediapotamon could not be found in previous literature, but the characters could be observed from various specimens from SYSU.

Comparative material. Sinopotamon anyuanense Dai, Zhou & Peng, 1995: 1 male (45.7 × 39.1 mm) ( SYSU 001080), Shaoguan City, Guangdong Province, China, April, 2013; Sinopotamon chekiangense Tai & Sung, 1975: 1 male (32.0 × 26.1 mm) ( SYSU 001079), Lucheng District, Wenzhou City, Zhejiang Province, China, March, 2013; Sinopotamon fukienense Dai & Chen, 1979: 1 male (45.7 × 39.1 mm) ( SYSU 001054), Fuqing City, Fujian Province, China, May, 2013; Mediapotamon leishanense Dai, 1995: 1 male (15.5 × 12.4 mm) ( SYSU 001094), Leishan County, Guizhou Province, China, coll. C. Huang, July, 2013.

Figures

FIGURE 7. Minutomon shanweiense, new genus, new species, male holotype (13.4 × 10.8 mm) (SYSU 001126). A, dorsal overall view; B, ventral view showing anterior thoracic sternum and abdomen; C, frontal view of carapace; D, ventral view showing sterno-abdominal cavity with right G 1 in situ (left G 1 removed).

FIGURE 8. Minutomon shanweiense, new genus, new species, male holotype (13.4 × 10.8 mm) (SYSU 001126). A, left G 2; B, left G 1 (ventral view); C, G 1 terminal segment (ventral view); D, left third maxilliped. (white bar = 1.0 mm)