Macrobrachium alevillalobosi nom. nov., 2021

Mantelatto, Fernando L., Pileggi, Leonardo G., Pantaleao, Joao A. F., Magalhaes, Celio, Villalobos, Jose Luis & Alvarez, Fernando, 2021, Multigene phylogeny and taxonomic revision of American shrimps of the genus Cryphiops Dana, 1852 (Decapoda, Palaemonidae) implies a proposal for reversal of precedence with Macrobrachium Spence Bate, 1868, ZooKeys 1047, pp. 155-198 : 155

Macrobrachium alevillalobosi nom. nov. comb. nov.

Cryphiops (Bithynops) villalobosi Villalobos Hiriat, Nates Rodríguez and Cantú Díaz Barriga, 1989: 166, figs 1-5, 7b, d, 8c. - Villalobos-Hiriart et al. 1993: 281, table 5 (list). - De Grave and Fransen 2011: 316 (catalog). - Álvarez et al. 2011: 258, fig. 2a. - Quiroz-Martínez et al. 2014: table S1 (list). - Alvarez and Villalobos 2016: 250, table 8.1 (list).

Cryphiops villalobosi . - Baldari et al. 2010: 48, fig. 1 (map), 52, table 1. - Botello and Álvarez 2013: 776, table 1 (list). - Mantelatto et al. 2020: 916 (key).

Material examined.

Holotype: Mexico - Chiapas • male, tl 51.8 mm; Municipality of Ocosingo, km 140 carretera Palenque-Ocosingo, ca. 5 km NW of the town of Ocosingo , Arroyo La Laja , 24 Jan. 1985, J.L. Villalobos, J.C. Nates, A. Cantú leg.; CNCR 3650 . Paratypes: 1 female, tl 42.7 mm, allotype; same data as for holotype; CNCR 3650 • 16 males, tl 44.3-57.0 mm, 7 females, 26.2 to 46.0 mm, 2 ovigerous females, 38.1, 42.7 mm; same date as for holotype; CNCR 3650a.

Additional material examined.

Mexico - Chiapas • 9 males, tl 25.0- 45.8 mm , 30 females, 36.8-39.2 mm; Municipality of Ocosingo, km 140 carretera Palenque-Ocosingo, ca. 5 km NW of the town of Ocosingo , Arroyo La Laja ; 07 Aug 1983; J.L. Villalobos, J.C. Nates, A. Cantú leg.; CNCR 2940 • 16 males, tl 24.3-54.5 mm, 23 females, tl 17.1-27.4 mm; Municipality of Yajalón, carretera Palenque-Ocosingo, Arroyo Yajalon ; 07 Aug. 1983; J.L. Villalobos, J.C. Nates, A. Cantú; CNCR 2941 .

Description.

Rostrum. Short, straight, reaching slightly beyond first third of third article of antennular peduncle; upper margin with 6-9 regularly spaced teeth, first one behind posterior edge of orbit; lower margin with 1-3 teeth.

Cephalon. Scaphocerite nearly 2.6 × as long as wide, outer margin straight.

Carapace. Smooth; antennal spine small, slightly overreaching lower portion of orbit; hepatic spine absent. Lower orbital angle obtuse, moderately pronounced.

Pereiopods . P1: slender, reaching with distal third of carpus beyond scaphocerite; carpus slightly longer than merus; chelae 0.68 length of carpus. P2: moderately robust, with small spines, equal in form and size, reaching with distal third of merus beyond scaphocerite; ischium 0.75 length of merus; merus as long as carpus; carpus as long as palm, with slight basal constriction; propodus 2.5 × as long as dactylus, and 1.6 × as long as carpus; palm compressed, nearly 5 × as long as high; fingers 0.62 length of palm, with numerous spinules, not gapping, tips crossing, cutting edge with 3-6 teeth on proximal third in both fingers. P3-P5 with all joints covered with rows of small spinules. P3 reaching with entire dactylus beyond scaphocerite, propodus 2.5 × as long as dactylus, propodus nearly 2 × as long as carpus, propodus slightly longer than merus. P4 reaching with entire dactylus beyond scaphocerite, propodus 3 × as long as dactylus, nearly 2 × as long as carpus, propodus slightly longer than merus. P5 reaching with half-length of dactylus end of scaphocerite, propodus 3 × as long as dactylus, propodus nearly 2 × as long as carpus, propodus slightly longer than merus.

Pleon. Smooth; somite 5 with posteroventral angle of pleuron acute; abdominal somite merely 2 × as long as somite 5. Inter-uropodal sclerite without keel-shaped pre-anal carinae.

Pleopods. PL2 with appendix masculina less than 2 × length of appendix interna.

Uropods. Exopodite with mobile spines as long as spiniform projection of outer margin.

Telson. Broad, smooth, slightly longer than abdominal somite 6, bearing two pairs of dorsal spinules close to posterior margin. Posterior margin ending in moderately acute triangular point; two pairs of posterior spinules with several plumose setae, inner pair overreaching distal margin of telson.

Etymology.

Villalobos Hiriart et al. (1989) dedicated this species to Dr. Alejandro Villalobos Figueroa, eminent Mexican carcinologist and founder of the CNCR. We maintain this homage by just adding the first part of his name to the specific epithet.

Size.

See in material examined.

Color.

Body translucid with orange punctuations.

Type locality.

México, Chiapas, Municipality of Ocosingo, Arroyo La Laja, km 140 carretera Palenque-Ocosingo, ca. 5 km NW of the town of Ocosingo.

Distribution.

Mexico, Chiapas, in the Valle de Ocosingo, Río La Virgen, Arroyos La Laja, Maravilla, Pasilá, and Yajalón ( Villalobos Hiriart et al. 1989).

Life cycle.

Exclusive of inland waters, therefore independent of brackish waters to complete its life cycle. The eggs are few and large: 1.3-2.4 mm ( Villalobos Hiriart et al. 1989). Its larval development is not known but given the characteristics of the eggs, it should be abbreviated, following the same pattern of congeners inhabiting continental waters ( Magalhães and Walker 1988; Pereira and García 1995).

Remarks.

The name Macrobrachium villalobosi was used by Hobbs Jr. (1973) for a new species from Mexico. Villalobos et al. (1989) used the same name for a new species of Cryphiops (Bithynops) also from Mexico. Since the synonymization of both genera makes these specific names secondary homonyms, Macrobrachium alevillalobosi is proposed as a replacement name for Cryphiops (Bithynops) villalobosi Villalobos Hiriat, Nates Rodríguez & Cantú Díaz Barriga, 1989.

Macrobrachium alevillalobosi nom. nov., comb. nov. differs from M. candango nom. nov. and M. perspicax comb. nov. mainly in the form, size, and proportion of the articles of the second pereiopod (Table 2 ). The chelipeds are long and similar in size and shape, overreaching the scaphocerite with distal third of the merus; the ischium is shorter than merus; the palm is long and cylindrical, almost five times as long as high, and the dactylus is 0.62 times the length of the palm. Finally, M. alevillalobosi nom. nov., comb. nov. is the only species of this group in which the appendix masculina is almost as long as the endopod of the second pleopod.