Leptalpheus corderoae, Salgado-Barragán, José, Ayón-Parente, Manuel & Hendrickx, Michel E., 2014

Salgado-Barragán, José, Ayón-Parente, Manuel & Hendrickx, Michel E., 2014, A new species of Leptalpheus Williams, 1965 and new records of L. mexicanus Ríos & Carvacho, 1983 and L. hendrickxi Anker, 2011 (Crustacea: Decapoda: Alpheidae) from the Pacific coast of Mexico, Zootaxa 3835 (4), pp. 573-582 : 574-578

publication ID	https://doi.org/ 10.11646/zootaxa.3835.4.8
publication LSID	lsid:zoobank.org:pub:449B1486-A86B-4245-AE33-419C777A7C2A
DOI	https://doi.org/10.5281/zenodo.6131115
persistent identifier	https://treatment.plazi.org/id/03C587E3-FFDB-FF84-FF66-CD857138F800
treatment provided by	Plazi
scientific name	Leptalpheus corderoae
status	sp. nov.

Treatment

Leptalpheus corderoae View in CoL sp. nov.

Figs. 2–5 View FIGURE 2 View FIGURE 3 View FIGURE 4 View FIGURE 5

Material examined. Holotype: 1 male (CL 7.6 mm), Estero Pérula, Chamela, Jalisco, Mexico, 19°35'22" N, 105°08'07” W, mudflat, near mangroves, yabby pump, 0.1–0.3 m, low tide, 7 March 2013 (EMU-10050). Paratypes: 4 males (CL 3.1–9.1 mm) and 4 females (CL 5.4–6.4 mm), same locality, 7 March 2013 (EMU-10051); 1 male (CL 5.8 mm) and 1 female (CL 7.4 mm), same locality 26 June 2013 (CNCR-28959); 2 males (CL 5.0– 7.2 mm), 3 females (CL 4.8–5.2 mm), same locality and date, 26 June 2013 (EMU-10052).

Description. Frontal margin of carapace triangular, without rostral projection, carapace smooth, without orbital crests ( Fig. 2 View FIGURE 2 A). Eyestalks with anteromesial margin rounded. Antennular peduncles ( Fig. 2 View FIGURE 2 A, B) moderately stout, flattened dorsoventrally; second article longer than wide; stylocerite appressed, not reaching distal margin of first article; ventromesial carina terminating in slender, upwards curving tooth and obtuse triangular process ( Fig. 2 View FIGURE 2 C); lateral flagellum with short secondary ramus. Antenna ( Fig. 2 View FIGURE 2 A, D) with stout basicerite bearing strong distoventral tooth; scaphocerite ovate, with small distolateral tooth reaching beyond anterior margin of moderately broad blade; carpocerite longer than scaphocerite and antennular peduncle. Mouthparts typical for genus, as illustrated ( Figs. 3 View FIGURE 3 A–E). Third maxilliped ( Fig. 3 View FIGURE 3 E) with lateral plate on coxa subacutely produced; ultimate article with brush-like rows of thick setae increasing in length distally.

Major cheliped ( Fig. 4 View FIGURE 4 A–C) with ischium unarmed; merus relatively slender, with concave depression along ventral margin, ventrolateral margin somewhat rugose; carpus very short, cup-shaped, dorsally convex, smooth; chela robust, longer than merus, with palm depressed ventromesially; irregular rows of tubercles extending from proximal half of palm to pollex, tubercles increasing in size distally; dorsal margin smooth; adhesive discs conspicuous; fingers about 0.6 palm length, not strongly twisted or curved, not gaping when closed; cutting edge of pollex with subtriangular, blunt, proximal tooth protruding on mesial side, and much stronger subdistal tooth protruding almost perpendicularly to main axis of pollex, together with much shorter apex; dactylus dorsally convex, longer than pollex, fitting into broad hiatus of pollex; cutting edge with broad low tooth, tip strongly but gradually curving; lateral surface of pollex and dactylus slightly rugose.

Minor cheliped ( Fig. 4 View FIGURE 4 D, E) with merus as long as chela, smooth; carpus short; chela smooth, fingers slender, as long as palm, proximal two third of cutting edges armed with small, regularly spaced teeth and one larger tooth at about 0.6–0.7 finger length; tips crossing distally.

Second pereiopod ( Fig. 5 View FIGURE 5 A) slender; ischium about 0.8 as long as merus; merus shorter than carpus; carpus five-articulated, article ratio approximately equal to 5:1:1:1:2; distal portion of chela with long setae.

Third and fourth pereiopods ( Figs. 5 View FIGURE 5 B, C) similar, with endopodal articles strongly compressed. Third pereiopod ( Fig. 5 View FIGURE 5 B) slightly longer and stouter than fourth; merus slightly longer than combined length of carpus and propodus; carpus with distoventral spiniform seta; propodus with two spiniform setae and several long setae along ventral margin, and two ventrodistal spiniform setae; dactylus slender, conical, gently curved, about half as long as propodus, with distodorsal setae. Fifth pereiopod ( Fig. 5 View FIGURE 5 D) slender, less compressed than third and fourth; ventral margin of propodus with seven distal rows of setae, latter increasing in number and length distally; dactylus strongly curved.

Male second pleopod ( Fig. 2 View FIGURE 2 E) with appendix masculina slender, with two subterminal and five terminal setae; appendix interna about 0.6 length of appendix masculina ( Fig. 2 View FIGURE 2 F). Uropod ( Fig. 2 View FIGURE 2 G) with lateral lobe of protopod ending in two small subacute teeth; exopod with distal margin truncate; diaeresis deeply incised, with large tooth near mesial margin; distolateral spiniform seta stout, not reaching distal margin of exopod.

Telson ( Fig. 2 View FIGURE 2 H) widest in proximal third, slightly tapering distally; dorsal surface with two pairs of strong spines inserted in deep pits close to lateral margin; posterior margin rounded, with two pairs of spiniform setae at posterolateral angles, lateral shorter than mesial, and with 14 plumose setae between mesial spiniform setae.

Ecology. Leptalpheus corderoae sp. nov. lives commensally in burrows of the callianassid ghost shrimp Lepidophthalmus bocourti , sometimes together with Leptalpheus hendrickxi (see below). Both species were also found in burrows situated closer to the mangrove trees and adjacent to the burrows of the mud shrimp Upogebia dawsoni . However, a possible association between L. corderoae sp. nov. and U. dawsoni remains to be confirmed.

Etymology. The species is named in honor of Mercedes Cordero-Ruiz, in recognition of her enormous support and numerous and significant contribution to the Laboratorio de Invertebrados Bentónicos, ICML, UNAM, in the last two decades.

Remarks. Leptalpheus corderoae sp. nov. is morphologically closest to L. azuero from the Pacific coast of Panama, and L. axianassae Dworschak & Coelho, 1999 from Brazil. The three species are very similar in the general shape of the major chela, the presence of large adhesive discs, the fingers not gaping when closed, the cutting edge of pollex armed with two large blunt teeth and with a short tip curved upward (similar to that of L. axianassae from Brazil), and the dactylus dorsally convex and ventrally tickened. The new species differs from L. azuero and L. axianassae by the presence of conspicuous tubercles on the ventral surface of the major chela (absent in L. azuero and L. axianassae ); specifically from L. azuero by the more obtuse rostrum (sharply triangular in L. azuero ), shorter stylocerite (not reaching distal margin of the first antennular article vs. overreaching this margin in L. azuero ), longer and more slender dactylus and propodus of third pereiopod, more slender scaphocerite, and the presence of 14 setae on the posterior margin of the telson (vs. eight in L. azuero ). The new species differs clearly from L. axianassae by having a slender antennular peduncle with stylocerite not reaching the anterior margin of the first article (overreaching it in L. axianassae ) and the lateral antennular flagellum possessing a short secondary ramus vs. a well developed secondary ramus in L. axianassae .

Leptalpheus corderoae View in CoL sp. nov. also has affinities to the L. pacificus Banner & Banner, 1974 View in CoL group ( Anker et al. 2006; Anker & Marin 2009), which is characterized mainly by the shape of the peculiar dentition of the major chela, slender antennular peduncles and tightly appressed stylocerite. However, the new species can be easily distinguished from the three species currently assigned to this group ( Anker & Marin 2009) by the major chela, e.g., by a different dentition on the fingers and the presence of tubercles on the ventral surface of the major chela palm and pollex.