Paranthura amorensis, Jarquín-Martínez & García-Madrigal, 2021

Jarquín-Martínez, Ubaldo & García-Madrigal, María Del Socorro, 2021, New genus and four new species of anthuroid isopods (Crustacea: Peracarida) from southern Mexican Pacific, Zootaxa 5048 (1), pp. 31-57 : 44-48

Paranthura amorensis n. sp.

Figs 8–10 , 14C ; Table 3

Material examined. Holotype: UMAR-PERA 581, non-ovigerous female, 5.7 mm (Playa del Amor, Zipolite , Oaxaca, tide pool, algae, Jul 3, 2007, coll. V. S. Rodríguez-Hernández et al.).

Additional material: Four specimens. Oaxaca: UMAR-PERA 582, 3 females, 1 undetermined (La Tijera Beach, Pochutla, dead coral, 2–4 m, Apr 30, 2005, coll. J. R Bastida-Zavala et al.) .

Diagnosis. Body with pigment spots in all somites and telson; pereonites 2–6 with central pigment spot; anteri- or region of pereonite 2 wider than posterior; pereonite 7 about 0.6 times the length of pleon. Flagellum of antennula with seven articles, article 3–6 with 1–2 aesthetascs. Mesial region of pereopod 1 with six pectinate setae; palm of pereopod 2 and 3 with seven sensory setae; exopod of pleopod 1 4.1 times wider than endopod, distally surrounded by 22 plumose setae, distal margin of telson with simple setae and some slight serration between setae.

Description holotype (non-ovigerous female UMAR-PERA 581)

Body ( Fig. 8A ) length 5.7 mm, about 8.6 times longer than greatest width, with pigment spots in all body, pereonites 2–6 with central pigment spot; anterior region of pereonite 2 wider than posterior; pereonite 7 about 0.6 times the length of pleon; pleon 1.1 times longer than wide, pleonite 1 free, pleonites 2–5 fused; pleonite 6 dorsally with slight medial incision on distal margin; telson linguiform, posterior margin with simple setae and slightly serration between setae.

Antennula ( Fig. 8B ) peduncle 2.1 times longer than flagellum; article 1 of peduncle 1.2 times longer than articles 2 and 3 together; article 2 subequal in length to article 3 with sensory plumose setae; article 3 with short distal setae. Flagellum of seven articles, slightly longer than two last articles of peduncle; article 3 with one aesthetasc; article 4–6 with two aesthetascs; last article tiny with long simple setae.

Antenna 2 ( Fig. 8C ) peduncle having article 2 most robust; article 4 with long distal seta; article 5 sub-equal to articles 3 and 4 together with row of simple setae on ventrodistal angle. Flagellum of 5 articles, article 1 rudimentary, last four articles minute with many simple setae.

Mandible ( Fig. 8D ) incisor acute, slightly longer than palp. Palp of three articles, article 1 shorter than article 3; second article 1.9 times longer than third; last article with comb-like longitudinal row of nine pectinate setae.

Maxilla ( Fig. 8E ) acute, with 12 distal teeth.

Maxilliped ( Fig. 8F ) palp of 2 articles, apical one minute; article 1 with one proximal seta and five distal ones; distal article with five setae.

Pereopod 1 ( Fig. 8G ) subchelate; carpus triangular with distal group of nine simple setae; propodus oval, 1.8 times longer than wide, palm ( Fig. 8H ) straight with cuticular convex ridge, margin bordered by simple setae, proximally projected ended by small lobe, and mesial region with row of six pectinate setae.

Pereopods 2–3 ( Fig. 9A–B ) similar in shape and size. Basis 2.5 times longer than wide; carpus triangular with 4–5 distal simple setae; propodus oval, 2.1 times longer than wide, palm slightly convex with some simple setae and seven sensory spines.

Pereopod 4 ( Fig. 9C ) basis two times longer than wide; carpus rectangular, 1.4 times longer than wide, ventral margin with setulae, three sensory spines and four distal setae; propodus cylindrical, 2.7 times longer than wide, ventral margin with three sensory spines.

Pereopods 5–7 ( Fig. 9D–F ) similar in shape to perepod 4; basis two times longer than wide; carpus 1.6 times longer than wide in pereopod 5 and 1.8 in pereopod, ventral margin with setulae and 2–3 sensory spines, distal margin with 3–4 long simple setae; propodus rectangular, 2.6 times longer than wide, ventral margin with three sensory spines. Pereopod 7 ( Fig. 9F ) longest, basis 1.8 times longer than wide; carpus two times longer than wide with two sensory spines and three long simple setae; propodus rectangular, 3.7 times longer than wide with three sensory spines.

Pleopod 1 ( Fig. 10A ) protopod with four retinaculae; exopod operculiform, 2.1 times longer than wide and 4.2 times wider than endopod, distally surrounded by 22 plumose setae and some short simple setae on dorsal surface; exopod narrow, 9.3 times longer than wide, distally with 11 plumose setae.

Pleopod 2 ( Fig. 10B ) exopod three times longer than wide, distally surrounded by 10 plumose setae; endopod 3.3 times longer than wide, slightly reaching beyond the apex of exopod, distal margin surrounded by four plumose setae. Pleopods 3–4 ( Fig. 10C–D ) similar to pleopod 2.

Pleopod 5 ( Fig. 10E ) wider than previous ones, exopod 2.1 times longer than wide, distally surrounded by nine plumose setae, lateral margin with two short setae; endopod shorter than exopod, 2.4 times longer than wide, distal margin with three plumose setae.

Uropodal protopod ( Fig. 10F ) rectangular, 2.1 times longer than wide, inner distal angle projected with two short simple setae, external margin with long simple setae. Endopod ovate, 1.5 times longer than wide, surrounded laterally and distally by 28 long simple setae and eight smeller sensory plumose setae.

Exopod ( Fig. 10G ) oval shape with acute tip, 2.3 times longer than wide, external and distal margin surrounded by plumose setae and simple ones.

Etymology. The species name is derived from the type locality, the beach “Playa del Amor”, where the holotype specimen was found.

Habitat. Intertidal to subtidal (4 m). In dead coral and algae.

Geographic distribution. Central coast of Oaxaca, from Playa del Amor , Zipolite to La Tijera Beach, Pochutla .

Remarks. Paranthura amorensis n. sp. and P. tientai n. sp. are different from other species previously recorded in the Tropical Eastern Pacific ( Table 3) by the following characteristics: first pleonite is free, 2–5 fused, and antenna flagellum has five articles. These two new species are similar in the following characteristics: article 3 of mandibular palp with nine robust setae; antennula flagellum long with more than five articles and numerous aesthetascs; and maxilliped palp with two articles. However, are different because P. amorensis n. sp. has punctate pigment throughout the body and pereonites 2–6 with dense central pigment spot ( Fig. 8A ); antennula flagellum has seven articles, articles 3–6 with 1–2 aesthetascs in each article ( Fig. 8B ); mandible incisor slightly longer than palp and straight ( Fig. 8D ); pereopod 1 palm with few marginal setae and mesial region with row of six pectinate setae ( Fig. 8H ); while Paranthura tientai n. sp. has diffuse pigment on pereonite 4 and 5 ( Fig. 11A ); antennula flagellum has five articles, articles 2–5 with 1–3 aesthetascs in each article ( Fig. 11B ); mandible incisor longer than palp and slightly curved ( Fig. 11D ), pereopod 1 palm with numerous marginal setae and mesial region with row of 17 short setae (Fig. 12B). Paranthura amorensis n. sp. can be easily distinguished from all Paranthura species by the following diagnostic characteristics: 1) presence of punctate pigment throughout the body, pereonites 2–6 with central pigment spot; 2) antennula flagellum of seven articles; 3) pereopod 1 mesial region with row of six pectinate setae.

Figures

FIGURE 8. Paranthura amorensis n. sp., holotype, female, 5.7 mm, UMAR-PERA 581, Playa del Amor, Zipolite, Oaxaca.A) Body, dorsal view with detail of the telson; B) antennula; C) antenna; D) mandible; E) maxilla; F) maxilliped; G) pereopod 1; H) palm of pereopod 1.

FIGURE 9. Paranthura amorensis n. sp., holotype, female, 5.7 mm, UMAR-PERA 581, Playa del Amor, Zipolite, Oaxaca.A) Pereopod 2; B) pereopod 3; C) pereopod 4; D) pereopod 5; E) pereopod 6; F) pereopod 7.

FIGURE 10. Paranthura amorensis n. sp., holotype, female, 5.7 mm, UMAR-PERA 581, Playa del Amor, Zipolite, Oaxaca.A) Pleopod 1; B) pleopod 2; C) pleopod 3; D) pleopod 4; E) pleopod 5; F) uropodal endopod; G) uropodal exopod.

FIGURE 11. P. tientai n. sp., Holotype, female, 7.4 mm, UMAR-PERA 579, El Arrocito Beach, Oaxaca.A) Body, dorsal view and detail of telson; B) antennula; C) antenna with detail of flagellum; D) mandible; E) maxilla; F) maxilliped.

FIGURE 14. Dorsal view of anthuroids from the southern Mexican Pacific: A) Negoescuanthura bastidai n. sp., paratype, ovigerous female (UMAR-PERA 571); B) Colanthura gabinae n. sp., holotype, female (UMAR-PERA 572); C) Paranthura amorensis n. sp., holotype, female (UMAR-PERA 581); D) P. tientai n. sp., holotype, female (UMAR-PERA 579). Scale bars: 1 mm (ACD); 0.5 mm (B).