Caecidotea zacapuensis, García-Vázquez & Pedraza-Lara & Rodríguez-Almaraz, 2021

García-Vázquez, Leonardo, Pedraza-Lara, Carlos & Rodríguez-Almaraz, Gabino, 2021, Six new epigean species of Caecidotea (Isopoda: Asellidae) distributed along the Trans-Mexican Volcanic Belt in Central Mexico, Zootaxa 4965 (1), pp. 45-77: 70-75

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Caecidotea zacapuensis

sp. nov.

Caecidotea zacapuensis   sp. nov.

( Figs 22–25 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 )

Material examined: Holotype, male ( CNCR 35522), length 7.5 mm, Laguna de Zacapu , 19°49’37.00”N, 101°47’23.00”W, elev. 1993 m, Municipality Zacapu, Michoacan, Mexico, 20 March 2018, coll. L. García-Vázquez and C. Pedraza-Lara. GoogleMaps  

Paratypes, male ( CNCR 35523), length 7.6 mm; same data of collection and collectors as holotype; dissected parts left pereiopod I, left pereiopod IV   , pleopod II; dissected structures for right pleopod drawings I, III, IV and V in the specimen tube. 20 Males and 15 females ( CNCR 35524)   .

Diagnosis. Male body length 3.4 width. Head trapezoidal, width 2.4 length, anterior margin concave; eyes length 3.8 width. Pleopod III with 36 plumose marginal setae. Exopod pleopod IV with proximal incomplete transverse suture. Uropods length 0.7 pleotelson length.

Description. Male (CNCR 35522) 7.5 mm ( Fig. 22A View FIGURE 22 ); head trapezoidal, width 2.4 length, anterior margin concave; eyes present, oval, dark pigmented, length 3.8 width. Postmandibular lobes not produced. Subrectangular pereionites lateral margins with simple setae, pereionites 1–5 straight, pereionites 6–7 rounded.

Pereionite 1 length 1.2 pereionite 2 length; pereionite 1 1.1 pereionite 3 length; pereionites 6–7 with lateral margins rounded, widening posterior.

Antennula flagellum with 10 articles, longer than distal antenna podomere middle; last four segments with aestetascs in formula 1–0–1–1. Antenna flagellum with 65 articles; proximal article width 1.2 length; following articles decreasing in length.

Pereiopod I ( Figs 22B View FIGURE 22 , 23A – B View FIGURE 23 ) dactylus outer edge with 10 simple setae; dactylus longer than palm; palmar margin with row simple setae; proximal process with 3 robust spines; mesial process acute, as wide as dactylus; distal process small acute triangular. Pereiopods II–III ( Fig. 22C–D View FIGURE 22 ) similar length. Pereiopod IV ( Figs 22E View FIGURE 22 , 23C View FIGURE 23 ) propodus with spine in dactylus, dactylus length 0.6 propodus length, dactylus with 4 slender spines on lower margin. Pereiopod V ( Fig. 22F View FIGURE 22 ) basis length 1.2 propodus length. Pereiopod VI ( Fig. 22G View FIGURE 22 ) similar length to pereiopod VII, basis length 1.3 propodus length. Pereiopod VII ( Fig. 22H View FIGURE 22 ) length 0.6 body length.

Pleopod I ( Fig. 24A View FIGURE 24 ) length 2.2 pleopod III length; basal segment oval, proximal margin straight, length 1.4 width, inner margin with 6 retinacula, distal segment oval, external margin medially straight, length 1.9 width, margins with 20 simple setae.

Pleopod II ( Fig. 25A–F View FIGURE 25 ), protopod subrectangular, proximal edge rounded, internal margin with 2 simple spines; exopod oval with small cuticular scales on inner and outer margin, exopod margin with 22 plumose setae; endopod slender, curved mesial surface, length 3.2 width, length 0.9 exopod length, length 0.7 protopod length, internal and external processes prominent; endopod apex with 3 processes: cannula short subcylindrical surpassing caudal process, like a semi-rolled sheet; mesial process evident; caudal process robust, subconical, with rounded apex, armed on subapical dorsal surface with 2–17 cuticular scales.

Pleopod III ( Fig. 24B View FIGURE 24 ), exopod oval, length 1.5 width, width 1.6 endopod length, transverse suture in proximal half, 36 plumose setae in distal and proximal margins; endopod subrectangular, length 0.9 exopod length.

Pleopod IV ( Fig. 24C View FIGURE 24 ), exopod length 1.6 width, external proximal margin with incomplete transverse suture, close to pleopod joint; endopod length 0.8 exopod length.

Pleopod V ( Fig. 24D View FIGURE 24 ), exopod oval, length 1.8 width, transverse suture not evident; endopod length 0.9 exopod length, width 0.8 exopod width.

Pleotelson ( Fig. 24E View FIGURE 24 ), subsquare, length 1.0 width, lateral margins parallel, with simple marginal setae, caudomedial lobe produced subacute.

Uropods ( Fig. 24E View FIGURE 24 ), length 0.7 pleotelson length, armed with robust marginal setae, apical endopod setae, exopod length 1.2 endopod length; protopod length 1.1 exopod length.

Habitat. This species was located on the shore of the Zacapu lake, between the roots of the aquatic vegetation, in the water lily Eichornia crassipes   .

Distribution. Known only from the type locality.

Etymology. This species is named after the municipality Zacapu, where it inhabits.

Remarks. The pleopod IV of Caecidotea zacapuensis   sp. nov. is similar to the one of Caecidotea buzwilsoni   sp. nov. from Yuriria Lagoon. Both can be differentiated using the transverse suture in pleopod IV: incomplete in Caecidotea zacapuensis   sp. nov., and complete in Caecidotea buzwilsoni   sp. nov.


Royal British Columbia Museum - Herbarium