Negoescuanthura, 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 : 33-34

Negoescuanthura n. gen.

Diagnosis. Body pigmented or not. Pereonite 7 with posterodistal angles strongly produced reaching more than half of pleonite 2. Uropodal protopod reaching 87% of telson length, and 2.5 times as long as endopod; exopod narrowly lanceolate, without dorsal lobe and more or less notched, 3–4 times as long as basal width. Pleotelson elongated, 2.3–3 times as long as wide, tapering in distal half to an acute apex. Articles 3–5 of antenna peduncle with suckerlike cuticular structures; flagellum of more than 30 articles, longer than or slightly shorter than peduncle. Last article of mandibular palp with row of 20–25 setae, the apical one longest. Maxillipedal endite reaching more than half of palp; palp half as long as basis with two free articles.

Type species. Negoescuanthura bastidai , new species, here designated.

Etymology. Named after Dr. Ileana Negoescu for having described the first species belonging to this new genus, in combination with “ anthura ” stem.

Remarks. This new genus is similar to Accalathura Barnard, 1925 , in shape and length body, multiarticulate flagellum on both pairs of antennae, pereopod 1 with palmar lobe defined by an obtuse angle and rows of compound setae, and posterodistal angle of pereonite 7. However, Accalathura has the pereonite 7 reaching the proximal region of pleonite 2, antenna flagellum has fewer than 30 articles, except in the circum-antarctic species A. gigas (Whitelegge, 1901) and A. gigantissima Kussakin, 1967 ; while in Negoescuanthura n. gen., the pereonite 7 reaching more than half of pleonite 2, antenna flagellum has more than 30 articles. Additionally, Negoescuanthura n. gen., has articles 3–5 of antennal peduncle with sucker-like cuticular structures, whereas, in Accalathura are absent ( Table 1).

Negoescu (1994) described Accalathura singularia from New Caledonia, mentioning that differs from other species of Accalathura , mainly by the presence of cuticular structures on antenna peduncle and great number of flagellum articles in both antennae (>30). These features would have allowed her to consider this new species in a new genus; however, due to that A. singularia was described based in a single specimen, Negoescu (1994) maintained it in the genus Accalathura . In this study, based on several specimens revised, is described a new species with same diagnostic genus-level characters as A. singularia , and this new species is established as type species of Negoescuanthura n. gen.

Negoescuanthura n. gen. is the only anthuroid genus known to exhibit sucker-like cuticular structures on the antennal peduncle; however, similar structures have been recorded in another crustacean taxa (e.g., the tanaidacean Pagurapseudes and the isopod Ligia ). In this study, all the specimens revised of Negoescuanthura were found in tubes of sabellariid polychaetes and dead coral, therefore, there may be is a relationship between the cuticular structures and the type of substrates, since the presence of tubular cavities helps them to remain anchored to these spaces, as has been observed in the genera Pagurapseudes and Ligia , that present similar structures in the pereopods with which they are fixed to the substrate ( Negoescu 1994).

Species: Negoescuanthura singularia ( Negoescu, 1994) comb. nov., N. bastidai n. sp.