Negoescuanthura bastidai, 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 : 34-38

publication ID	https://doi.org/ 10.11646/zootaxa.5048.1.2
publication LSID	lsid:zoobank.org:pub:CD0AF5A5-B9A4-41F5-8F02-6E443CDE05A6
persistent identifier	https://treatment.plazi.org/id/0392E33E-470D-B262-EE95-FEEDFA708240
treatment provided by	Plazi
scientific name	Negoescuanthura bastidai
status	sp. nov.

Treatment

Negoescuanthura bastidai View in CoL n. sp.

Figs 2–4 View FIGURE 2 View FIGURE 3 View FIGURE 4 , 14A View FIGURE 14

Material examined. Holotype: UMAR-PERA 566, Non-ovigerous female, 14.3 mm (Estacahuite Beach, Puerto Ángel , Oaxaca, dead coral, 5 m, Apr 9, 2005, coll. J. R. Bastida-Zavala et al.) . Allotype: UMAR-PERA 567, male, 10.3 mm, same sampling location as the holotype. Paratypes: UMAR-PERA 568), 3 ovigerous females, 3 nonovigerous females, 2 immature males, same sampling location as the holotype .

Additional material: 13 specimens. Guerrero: UMAR-PERA 564, 1 ovigerous female, 3 non-ovigerous females, 2 mancae (La Roqueta Island, tubes of sabellariid polychaetes, 2 m, Sep 21, 2007, coll. M.S. García-Madrigal et al.); UMAR-PERA 565, 1 non-ovigerous female (Coral Beach, Ixtapa, E-1A, dead coral, 1.5 m, Sep 19, 2007, coll. M.S. García-Madrigal et al.). Oaxaca: UMAR-PERA-569, 2 ovigerous females, 1 non-ovigerous female (Estacahuite Beach, Puerto Ángel, dead coral, 2–4 m, May 18, 2005, coll. J. R. Bastida-Zavala et al.); UMAR-PERA 570, 2 ovigerous females (La Tijera Beach, Pochutla, dead coral, 2–4 m, Apr 30, 2005, coll. J. R. Bastida-Zavala et al.); UMAR-PERA 571, 1 ovigerous female ( San Agustín Bay , Huatulco, dead coral, 4 m, Nov 8, 2019, coll. U. Jarquín-Martínez) .

Diagnosis. Antennula shorter than antenna; antennula flagellum 1.8 times the length of peduncle with 23 articles; antenna flagellum of 32 articles, slightly shorter than peduncle. Pereopod 1 carpus with five robust pectinate setae; propodus two times longer than broad, proximal region of the palm with 12 robust pectinate setae; pereopod 2 and 3 carpus with two distal hand-like sensory spines; pereopod 4 propodus with seven sensory spines; pereopod 7 propodus with eight sensory spines. Uropodal exopod is three times longer than basal wide. Telson 2.3 times longer than wide.

Description holotype (non-ovigerous female UMAR-PERA 566)

Body ( Fig. 2A View FIGURE 2 ) length 14.3 mm, about 12.1 times longer than wide with pigment from the first antennae article to pleotelson; clusters of long setae present laterally on pereon at articulations of pereopods. Eyes well developed, occupying much of the lateral lobes. Pereonite 7 shorter than others, 2.2 times longer than wide with posterodistal angles produced reaching more than half of pleonite 2. Telson ( Fig. 2B View FIGURE 2 ) elongate, 2.3 times longer than wide, tapering in the distal part to an acute apex, slightly serrate and bordered by numerous long simple setae.

Antennula ( Fig. 2C View FIGURE 2 ) shorter than antenna. Article 1 with short sensory setae, 1.8 times longer than article 2; article 2 and 3 similar lengths, article 3 with long simple setae on distal margin. Flagellum 1.8 times the length of peduncle with 23 articles; first very short; second longest and other ones cylindrical and sub-equal; beginning with article 5, each article bears one short aesthetasc and 2–3 setae.

Antenna ( Fig. 2D View FIGURE 2 ) article 2 of peduncle large, 1.8 times longer than wide with scales on lateral margins and patch of small setae in middle surface, external margin with two long setae; ventral surface of article 3–5 bears sucker-like cuticular structures. Flagellum of 32 articles, slightly shorter than peduncle, each article with bunches of short setae.

Mandible ( Fig. 2E View FIGURE 2 ) palp of three articles, first 0.3 times shorter than second; article 2 oval with six long setae and setulated scales; article 3 with longitudinal row of 24 short robust setae and one long apical robust seta with associated short single setae.

Maxilla ( Fig. 2F View FIGURE 2 ) slender and elongated with 15 distal denticles.

Maxilliped ( Fig. 2G View FIGURE 2 ) palp of 2 articles; article 1 half the length of distal article, with six setae on inner edge and scales on dorsal edge; article 2 with one seta at mid-length and 14 long terminal setae; basis with scales on dorsal margin, endite reaching more than half of article 2 of palp with one subterminal long seta.

Pereopod 1 ( Fig. 3A View FIGURE 3 ) subchelate, basis and ischium with rows of long dorsal setae; merus broader than long and partially covered by ischium, ventral edge lobed with row of simple setae; carpus embedded between merus and propodus, ventral margin lobed with cluster of five robust setulated setae and long simple setae; propodus two times longer than broad, palm ( Fig. 3B View FIGURE 3 ) almost straight with cuticular ridge, proximal part projected ended in lobe and bordered by 12 robust setulated setae, mesial surface near the palm densely setose with smooth and pectinate setae.

third article of palp; F) maxilla; G) maxilliped.

sensory spines; E) pereopod 3; F) palm of pereopod 3; G) pereopod 4; H) pereopod 5; I) pereopod 6; J) pereopod 7.

567. E) Antennula; F) antenna; G) pleopod 2.

Pereopod 2 ( Fig. 3C View FIGURE 3 ) basis and ischium with paired rows of long dorsal setae; merus with long dorsal and ventral setae; carpus triangular with long ventral setae; propodus elongate oval, 2.6 times longer than wide, ventral margin with eight setulated sensory spines ( Fig. 3D View FIGURE 3 ), fourth and fifth largest, seventh and eighth most distal spines are hand-like; mesial surface with rows of long simple setae.

Pereopod 3 ( Fig. 3E View FIGURE 3 ) is similar in shape and size to pereopod 2. Basis and ischium with row of long dorsal setae; propodus elongate oval, 3.2 times longer than broad, ventral margin with nine setulated sensory spines ( Fig. 3F View FIGURE 3 ), eighth and ninth most distal spines are hand-like.

Pereopod 4 ( Fig. 3G View FIGURE 3 ) basis with dorsal simple seta and sensory plumose setae; ischium with long dorsal and ventral setae; carpus 2.3 times longer than wide, ventral margin with six sensory spines and row of long setae; propodus cylindrical, 3.4 times longer than wide, ventral margin with seven sensory spines and row of short setae.

Pereopods 5–6 ( Fig. 3H–I View FIGURE 3 ) similar in shape and size to pereopod 4.

Pereopod 7 ( Fig. 3J View FIGURE 3 ) slender; carpus sub-rectangular, 0.7 times longer than wide, ventral margin with five sensory spines and row of long simple setae; propodus cylindrical, 4.6 times longer than wide, ventral margin with nine sensory spines and row of short simple setae, dorsodistal margin with four simple sensory spines.

Pleopod 1 ( Fig. 4A View FIGURE 4 ) protopod with six retinaculae; exopod oval, two times longer than wide, distal margin surrounded with at least 94 long plumose setae; endopod cylindrical, 0.4 times the width of exopod, distal margin surrounded by 19 plumose setae.

Pleopod 2 ( Fig. 4B View FIGURE 4 ) shorter than pleopod 1, endopod and exopod similar size; exopod with around 18 apical plumose setae; endopod with around 13 apical plumose setae. Pleopods 3–5 similar to pleopod 2 exopod with row of plumose setae on dorsal edge.

Uropodal protopod ( Fig. 4C View FIGURE 4 ) two times longer than wide, ventral and dorsal margins with row of long setae, inner distal angle raised. Endopod conical, distal margin rounded, 1.4 times longer than wide with rows of long simple setae.

Exopod ( Fig. 4D View FIGURE 4 ) exceeding the length of protopod, three times longer than basal wide, distally narrow, ventrodistal margin slightly concave, dorsal and ventral margins with long plumose and simple setae (simple setae concentrated apically).

Male (dimorphic characters based on the allotype, UMAR-PERA 567, 10.3 mm)

Antennula ( Fig. 4E View FIGURE 4 ) peduncle robust than female; flagellum two times longer than peduncle with 20 articles, articles 2–11 with dense cluster of aesthetascs and seta, distal articles (>11) with one short aesthetasc and with bunches of short setae.

Antenna ( Fig. 4F View FIGURE 4 ) peduncle similar to female, sucker-like cuticular structures only present on article 4; flagellum slightly shorter than peduncle with 26 articles with bunches of short setae.

Pleopod 2 ( Fig. 4G View FIGURE 4 ) endopod and exopod similar size; exopod 2.7 times longer than wide, distal margin surrounded by 16 plumose setae; endopod 3.8 times longer than wide, distal margin surrounded by 13 plumose setae; appendix masculine longer than rami, apically bifid, spoon-shaped external projection, proximal region with setulated scales.

Variation. Aesthetascs increase in number on antennula flagellum ( Fig. 4E View FIGURE 4 ), while cuticular structures decrease on antennal peduncle in sexually mature males ( Fig. 4F View FIGURE 4 ).

Etymology. This new species is named after Dr. J. Rolando Bastida-Zavala, the researcher who collected the type specimens.

Habitat. Intertidal to subtidal (1.5–5 m). In dead coral and tubes of sabellariid polychaetes.

Geographic distribution. Southern Mexican Pacific , from Guerrero to Oaxaca.

Remarks. The cuticular structures on articles 3–5 of antennal peduncle, are present in all analyzed female specimens; however, in males, these structures are variable, in juvenile males, cuticular structures are as females, whereas in mature males these structures decrease and are only present in one article ( Fig. 4F View FIGURE 4 ). Among all specimens, only one terminal male was found. Nevertheless, this one is very different, the cuticular structures of antenna of this terminal male are absent, maxilliped endite is longer than palp, carpus of pereopod 1 have a strong tooth, palm without proximal projection, and pereopods 2–7 have smaller number of sensory spines compared with females and mature females.

The new species is similar to Negoescuanthura singularia , from New Caledonia, by the presence of cuticular structures on peduncular articles 3–5 of antenna and antenna flagellum with 30–32 articles. However, are different because in N. singularia the uropodal exopod is straight, four times as long as basal width, telson is three times as long as wide, propodus of pereopods 4 and 7 have 13 and 17 sensory spines, respectively, and propodus of pereopods 2 and 3 have simple spines on ventral margin; while in N. bastidai n. sp. the uropodal exopod is slightly notched, three times as long as basal width, telson 2.3 times as long as wide, propodus of pereopods 4 and 7 have seven and eight sensory spines, respectively, and propodus of pereopods 2 and 3 have two distal hand-like spines.