Cortezura caeca Jarquín-Martínez & García-Madrigal 2021, sp. nov.

Cortezura caeca sp. nov.

urn:lsid:zoobank.org:act: AE0F227A-7FA9-4897-B29F-7C32EBF9214A

Figs 5–7, 20B

Etymology

This species is named after ‘ caeca ’ due to the absence of eyes.

Material examined

Holotype MEXICO • ♀ (body length 7.1 mm); Oaxaca, Huatulco, Jicaral Beach; 15°42′38″ N, 96°11′49″ W; depth 12 m; 11 Feb. 2007; V. Hernández-Urraca and L. Estrada-Vargas leg.; coral; UMAR-PERA 534.

Paratypes MEXICO • 1 ♂ (body length 8 mm); same collection data as for holotype; UMAR-PERA 535 • 1 ♀; same collection data as for holotype; UMAR-PERA 536.

Additional material

MEXICO – Oaxaca • 1 ♀; Pochutla, La Tijera Beach; 15°41′13″ N, 96°26′36″ W; depth 8 m; 24 Apr. 2009; D. Zavala-Casas leg.; sand; UMAR-PERA 537 • 3 ♀♀, 1 ♂; Huatulco, Copalita Beach, in front of the mouth of the Copalita River; 15°47′17″ N, 96°3′5″ W; depth 10 m; 7 May 2007; E. Morales- Domínguez and C. Hernández-Tlapale leg.; sediment; UMAR-PERA 538.

Description

Holotype (♀, UMAR-PERA 534)

BODY (Figs 5A, 20B). Length 7.1 mm, about 11.8 times as long as wide with a whitish color, without pigment. Body proportion: C<1=2>3<4<5>6>7. Cephalon 1.3 times as long as wide, rostral process equal to lateral lobes, eyes absent; overlapping antennas, forming a flattened surface. Pleon equals to the length of the pereonite 7; pleonites 1–5 fused, pleonite 6 free. Telson 2.6 times as long as wide, tapering distally with two proximal statocysts, mid-distal margin with a group of short setae; apex broadly truncate, slightly sinuous with eight sub-marginal and eight marginal setae.

ANTENNULE (Fig. 5B). Peduncle with three articles. First article 1.2 times as long as second, with four simple setae and plumose sensory setae; article 2 with four long simple setae and scales in ventral margin; article 3 narrow than others with a group of ventrodistal setae and a long apical seta; flagellum of three articles, distal article with three aesthetascs.

ANTENNA (Fig. 5C). Peduncle with five articles. Article 2 with scales in ventral margin; articles 3 and 4 sub-equal; article 5 subrectangular, 1.2 times as long as article 4; flagellum with three articles, article 1 longer than the others; distal articles with numerous setae.

MAXILLIPED (Fig. 5D). Palp with two articles. Article 1 large, 1.3 times as long as wide, internal margin with four setae, external margin with one seta, distal angle with two setae; distal article oblique with three distal wide setae. Endite present, with fine distal setae.

MAXILLA (Fig. 5E). With seven stout distal teeth.

MANDIBLE (Fig. 5F). Symmetrical; palp with two articles, article 1 with a simple distal seta; distal article 1.8 times as long as article 1, whit three mid-distal setae and one long apical. Incisor with three teeth; lacinia mobilis with approximately 13 denticles, sharp molar.

PEREOPOD 1 (Fig. 6A). Subchelate; carpus triangular, apically rounded with a group of distal simple setae; propodus ovate, palm curved, slightly medially convex with a row of 11 short setae; dactylus reaching almost half the palm, internal distal angle with a tooth; unguis slender, reaching the apical margin of the carpus.

PEREOPODS 2–3 (Fig. 6B–C). Similar in shape and size. Ischium, merus and carpus with numerous ventral simple setae; inner margin of merus denticulate; carpus triangular, partially below the propodus with 2 robust setae on the distal margin; propodus cylindrical, 2 times as long as wide, internal margin with setulated scales, distoventrally one serrated sensory spine and a group of simple setae.

PEREOPODS 4–7 (Fig. 6D–G). Similar in shape and size. Inner margin of ischium and merus slightly denticulate and numerous simple setae; carpus pentagonal, ventrodistal margin with a single sensory spine and a group of long setae; propodus cylindrical, approximately half the width of the carpus, internal margin with a group of simple setae and setulated scales, ventrodistal margin with a serrate sensory spine and 1–2 pectinate spines; pereopod 7 dactylus with setulated scales on the inner and outer margins. Pereopods 2–7 basis with a long simple seta and plumose sensory setae; merus, carpus and propodus with scales.

PLEOPOD 1 (Fig. 7A). Protopod with three retinaculae; exopod operculiform, 2.4 times as long as wide, surrounded distal and laterally by 28 plumose setae; endopod almost half as wide as exopod with seven plumose setae.

PLEOPOD 2 (Fig. 7B). Exopod surrounded distally by 11 plumose setae; endopod surrounded by eight plumose setae.

UROPODAL PROTOPOD (Fig. 7C). Rectangular, 2 times as long as basal width, outer margin with plumose setae.

UROPODAL ENDOPOD (Fig. 7C). Subtriangular, 1.5 times as long as wide, rounded apex, outer and apical margin with long simple setae and plumose sensory setae.

UROPODAL EXOPOD (Fig. 7D). Auriculiform, dorsal surface with short setae, external margin with 24 simple setae and numerous plumose setae.

Male (dimorphic characters; based on the paratype ♂, UMAR-PERA 535)

ANTENNULE (Fig. 7E). Peduncle with three articles; article 2 projected internal distal angle; flagellum robust with four articles, article1 circular; article 2 with numerous aesthetascs; articles 3 and 4 smaller.

MANDIBLE. Mandibular palp with two articles; distal article with seven long setae.

PEREOPOD 1 (Fig. 7F). Subchelate; palm concave with a strong middle tooth and numerous marginal and mesial setae; distoventral angle of dactylus slightly projected.

PLEOPOD 2 (Fig. 7G). Similar to the female; exopod surrounded distally by 10 plumose setae; endopod surrounded by seven plumose setae; male appendix emerging from the middle part of the endopod, slightly longer than ramus, apex rounded and slightly bent towards the inside.

Distribution and habitat

From Puerto Ángel to Huatulco, Oaxaca. In coral, sand and sediment; subtidal (12 m).

Remarks

Cortezura caeca sp. nov. differs from the two previously recorded species of this genus, C. penascoensis, described from Puerto Peñasco, Sonora, and C. confixa (Kensley, 1978) described from Cubagua Island, Venezuela, by the following unique characteristics: distal article of the mandibular palp with four medial setae and one apical, lacinia mobilis with 13 denticles, telson with distolateral carina, distal region with eight subapical setae and eight apical. Cortezura caeca sp. nov. is similar to C. penascoensis as follows: (1) form of telson, (2) palm of pereopod 1, and (3) maxilla. However, in C. caeca sp. nov. the distal article of the mandibular palp has four medial setae and one apical, lacinia mobilis with 13 denticles, distally tapered telson and the apex is truncated, pereopods 2–7 with scales on the merus, carpus and propodus. And in C. penascoensis the distal article of the mandibular palp has six medial setae and one apical, lacinia mobilis presents 8 teeth, pleon with six conspicuous segments. The antennular flagellum of the male of Cortezura caeca sp. nov. has four articles and the palm of pereopod 1 has a strong tooth projected transversally, while C. penascoensis has one article on the flagellum, palm of pereopod 1 with tooth projected proximally.