Colanthura gabinae, 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 : 39-43

Colanthura gabinae n. sp.

Figs 5–7 , 14B , Table 2

Material examined. Holotype: UMAR-PERA 572, Non-ovigerous female, 2.7 mm (La Roqueta Island, Acapulco , Guerrero, tubes of sabellariid polychaetes, 2 m, Sep 21, 2007, coll. M.S. García-Madrigal et al.) Allotype: UMAR- PERA 573 , male, 3.4 mm, same sampling location as the holotypes . Paratypes: UMAR-PERA 574, 4 females, 3 males, same sampling location as the holotype .

Additional material: 35 specimens. Guerrero: UMAR-PERA 575, 2 ovigerous females , 3 males (La Roqueta Island, Acapulco , dead coral, 2 m, Sep 21, 2007, coll. M.S. García-Madrigal et al.); UMAR-PERA 576, 8 ovigerous females , 1 male, 4 immature females (Coral Beach, Ixtapa , dead coral, 1.5 m, Sep 19, 2007, coll. M.S. García- Madrigal et al.); UMAR-PERA 577 , 1 female (Coral Beach, Ixtapa , algae, intertidal, Sep 19, 2007, coll. M.S. García-Madrigal et al.). Oaxaca: UMAR-PERA-578, 3 ovigerous females, 4 non-ovigerous females , 9 males (Playa del Amor, Zipolite , algae, tide pool, Jul 3, 2007, coll. V. S. Rodríguez-Hernández et al.) .

Diagnosis. Body 7.3 times longer than wide, brow, with scales and some tiny setae. Rostrum slightly larger than lateral angles; antennular flagellum with four aesthetascs; article 2 of antennal peduncle with denticles on external margin. Pereopod 1 propodus 1.7 times longer than broad with row of 7–9 robust mesial setae; propodus of pereopod 6 with two robust setae in ventral margin; pleon subequal to pereonites 6 and 7 together; uropods subequal in length to telson; telson 2.2 times longer than broad and 0.9 times the length of pleon, distal margin with 16 setae.

Description holotype (non-ovigerous female UMAR-PERA 572)

Body ( Fig. 5A ) 7.3 times longer than wide, brow, covered with scales and some tiny setae. Cephalon almost as long as wide, 0.7 times the length of pereonite 1, rostrum slightly larger than lateral angles; eyes with approximately 14 omatids. Pleon ( Fig. 5B ) 1.1 times longer than telson, with suture lines between each pleonite. Uropods subequal in length to telson; telson ( Fig. 5C ) 2.2 times longer than broad and 0.9 times the length of pleon, distal margin with 16 setae.

Antennula ( Fig. 5D ) first article of peduncle 1.8 times longer than second, distal angle with plumose sensory setae; article 3 with three distal setae. Flagellum with four articles, 0.8 times the length of last peduncle article, articles 3 and 4 reduced with four aesthetascs.

Antenna ( Fig. 5E ) articles 2 of peduncle slightly larger than articles 3 and 4 together, external margin with denticles; last article 1.1 times longer than fourth, distal margin with six simple setae and sensory setae. Flagellum with only one rudimentary article with numerous setae.

Mandible ( Fig. 5F ) reduced; palp, incisor, lacinia, and molar process lacking.

Maxilla ( Fig. 5G ) styliform with 12 denticles.

Maxilliped ( Fig. 5H ) composed of one large free segment, with one medioventral seta, the subdistal region with three setae, and apical region with five setae.

Pereopod 1 ( Fig. 6A ) subchelate; carpus triangular with distal group of simple setae; propodus oval, 1.7 times longer than broad, palm with cuticular ridge and eight marginal short setae, proximal region projected, mesial region with row of 7–9 robust setae.

Pereopods 2 –3 ( Fig. 6B, D ) similar in shape and size; carpus triangular with three apical simple setae; propodus oval, 1.6–1.7 times longer than wide with setae and six sensory spines on ventral margin, dorsodistal margin with one plumose sensory seta.

Pereopods 4–6 ( Fig. 6F–H ) similar in shape and size; carpus rectangular, 0.5–0.7 times the length of propodus, internal margin with two sensory spines; propodus rectangular 2.3–2.4 times longer than wide in perepods 4 and 5, 2.9 times longer than wide in pereopod 6, internal margin with setulated scales and two sensory spines. Pereopod 6 propodus with two dorsodistal pectinate spines.

Pleopod 1 ( Fig. 7A ) protopod with three retinaculae; exopod operculiform, 2 times longer than wide, distally surrounded by 15 plumose setae, with some short setae on dorsal surface; endopod narrow, 0.2 width of exopod, distal margin surrounded by nine plumose setae.

Pleopod 2 ( Fig. 7B ) elongated oval; exopod longer than endopod, 2.6 times longer than wide, distal margin surrounded by eight plumose setae; endopod 3.7 times longer than wide, with three distal plumose setae.

Pleopods 3–5 ( Fig. 7C–E ) wider than pleopod 2.

Uropodal protopod ( Fig. 7F ) 1.6 times longer than wide, internal distal angle projected. Endopod subcircular, 1.5 times longer than broad, distal margin surrounded by simple and plumose setae.

Exopod ( Fig. 7G ) oval, 1.6 times longer than wide, surrounded by approximately 18 plumose setae and nine simple setae, surface with scales and some short setae.

Male (dimorphic characters based on the allotype, UMAR-PERA 573, 3.4 mm)

Antennula ( Fig. 7H ) robust, peduncle of 3 articles; article 1 longer than article 2 and 3 together. Flagellum with about 10 articles, articles 2–6 robust with dense cluster of aesthetascs, articles 7–10 smaller, distal article with two aesthetascs and some simple seta.

Pereopod 1 ( Fig. 7I ) similar to female; carpus triangular with distal group of simple setae; propodus oval, two times longer than broad, palm with six marginal short setae, mesial margin with nine robust setae.

Pleopod 2 ( Fig. 7J ) exopod cylindrical, 2.7 times longer than wide, slightly longer than endopod, distal margin surrounded by nine plumose setae; endopod 3.6 times longer than wide, surrounded distally by four plumose setae; appendix masculine longer than pleopodal rami, apex hook-shape and slightly wider.

Etymology. This species is named after the first author’s beloved mother, Gabina Martínez.

Habitat. Intertidal to subtidal (2 m). In tubes of sabellariid olychaetes, dead coral and algae.

Geographic distribution. Southern Mexican Pacific , Guerrero to Oaxaca.

Remarks. Colanthura gabinae n. sp. is similar to C. bruscai Poore, 1984 ( Table 2) in the presence of scales on the body, pleonite 1 two times longer than the second, form of antennae and number of aesthetascs on antennula, shape and ornamentation of pereopod 1, and the number of sensory spines of pereopod 2; however, differs because in C. bruscai the pleon is longer than pereonites 6+7 and is wide as long, pereopod 1 propodus with row of about nine mesial spines, and uropodal exopod broadly tapering, 1.8 times as long as greatest width; while C. gabinae n. sp. the pleon is shorter than pereonites 6+7 and 1.2 times width than long, pereopod 1 propodus with 7–9 mesial spines, and uropodal exopod sub-circular, 1.6 times longer than greatest wide. Colanthura gabinae n. sp. differ from all Colanthura species by the presence of two sensory spines in pereopods 4–6; pleopod 1 exopod two times longer than wide, surrounded distally with at least 15 plumose setae; telson 2.2 times longer than wide and 0.9 times the length of pleon.

6 with detail of dorsal spine.

male, 3.4 mm, UMAR-PERA 573. H) Antennula; I) pereopod 1; J) pleopod 2 with detail of male appendix.

Figures

FIGURE 5. Colanthura gabinae n. sp., holotype, female, 2.7 mm, UMAR-PERA 572, La Roqueta Island, Guerrero. A) Body, dorsal view; B) pleon; C) telson; D) antennula; E) antenna; F) mandible; G) maxilla; H) maxilliped.

FIGURE 6. Colanthura gabinae n. sp., holotype, female, 2.7 mm, UMAR-PERA 572, La Roqueta Island, Guerrero.A) Pereopod 1; B) pereopod 2; C) palm of pereopod 2; D) pereopod 3; E) palm of pereopod 3; F) pereopod 4; G) pereopod 5; H) pereopod

FIGURE 7. Colanthura gabinae n. sp. A–G. Holotype, female, 2.7 mm, UMAR-PERA 572, La Roqueta Island, Guerrero. A) Pleopod 1; B) pleopod 2); C) pleopod 3; D) pleopod 4; E) pleopod 5; F) uropodal endopod; G) uropodal exopod. H–J. Allotype,

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).