Nannoniscus ovatus Menzies & George 1972
Creators: name: Kaiser, Stefanie
name: Kihara, Terue Cristina
name: Brix, Saskia
name: Mohrbeck, Inga
name: Janssen, Annika
name: Jennings, Robert M.
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Isopoda
Nannoniscidae
Nannoniscus
Nannoniscus ovatus

description: NANNONISCUS OVATUS MENZIES & GEORGE, 1972
(FIG. 7A–F)
Material examined: Holotype, male, USNM Cat. No. 121022; allotype female (Vema.U-15–69), under the same accession number as the holotype.
Diagnosis: Body slender, length about 4.9 × pereonite 1 width; Mxp lateral margin devoid of setae; Mxp epipodite reaching proximal third of palpal article 3; pereonite 2 anterolateral tergites each with robust seta; pereonite 7 lacking ventral spine; Op with ventral posteriorly bent spine, posterior margin with ≤ nine simple setae; Urp uniramous, not projecting beyond Plt posterior margin; male PlpI with three hook-like projections distally.
Redescription of male holotype: Habitus (Fig. 7D–F), body length 4.9 × pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 7D) length 0.9 width. Anterior and lateral margins straight, posterior margin slightly rounded. Antennae inserting frontolaterally in deep fold. Pereonites 1 and 2 of equal width, pereonites 2–7 decreasing in width; pereonite 1 length 0.3 width. Pereonite 2 length 1.4 pereonite 1 length, length 0.5 width. Pereonites 2 and 3 of similar length; pereonite 4 length 1.5 pereonite 1 length. Pereonites 1–4 anterior margins frontally directed, rounded; anterolateral tergites of pereonite 2 each tipped with robust seta. Pereonite 5 length 1.2 pereonite 1 length, anterior margin straight. Pereonites 6 and 7 dorsomedially fused, pereonite 6 anterior margin strongly convex. Plt length 0.2 body length, length 1.4 width, width 0.8 pereonite 1 width; posterior margin strongly rounded; anterior margin convex. Urp (Fig. 7F) drawn in situ. Uniramous, length 0.3 Plt length, not projecting beyond posterior margin. Protopodite length 1.4 width. Endopodite length 1.4 protopodite length, length 4.4 width.
Description of female paratype: Habitus (Fig. 7A–C), body length 4.7 × pereonite 1 width. Coxae not visible in dorsal view. Cephalothorax (Fig. 7A) length 0.9 width. Anterior and lateral margins straight, posterior margin slightly rounded. Antennae inserting frontolaterally in deep fold. Op (Fig. 7B, C) length 1.4 width, with strong ventral spine, posteriorly bent. Lateral and posterior margins rounded, posterior margin with several (≤ 9) short simple setae. Pereonites 2–7 decreasing in width; pereonite 1 and 2 widest, pereonite 1 length 0.3 width, pereonite 2 length 0.4 width, length 1.5 pereonite 1 length. Pereonite 3 longest, length 2.1 pereonite 1 length. Pereonites 2, 4, 6 and 1, 5 and 7 of similar length. Pereonites 1–4 anterior margins frontally directed, rounded, anterolateral tergites of pereonite 2 each tipped with robust seta, tergites of pereonites 3 and 4 each with small simple seta. Pereonite 5 width 0.8 pereonite 1 width, its anterior margin slightly concave, pereonite 6 anterior margin strongly convex. Pereonites 6 and 7 fused. Plt length 0.2 body length, length 1.4 width, width 0.7 pereonite 1 width tapering towards distal end; posterior margin strongly rounded, anterior margin convex. Urp (Fig. 7C) drawn in situ. Uniramous, length 0.2 Plt length, not projecting beyond Plt posterior margin. Protopodite length 1.4 width, with three simple setae laterally. Endopodite length 1.1 protopodite length, length 4.5 width, with few simple setae terminally.
Remarks: Menzies & George (1972) did not provide a description of the female of N. ovatus. Yet, owing to gender-related dimorphism also known from nannoniscids (Wilson, 2008), both sexes are required for morphological comparison.
description: Published as part of Kaiser, Stefanie, Kihara, Terue Cristina, Brix, Saskia, Mohrbeck, Inga, Janssen, Annika & Jennings, Robert M., 2021, Species boundaries and phylogeographic patterns in new species of Nannoniscus (Janiroidea: Nannoniscidae) from the equatorial Pacific nodule province inferred from mtDNA and morphology, pp. 1020-1071 in Zoological Journal of the Linnean Society 193 on pages 1035-1037, DOI: 10.1093/zoolinnean/zlaa174, http://zenodo.org/record/5639160