Austroniscus ovalis Vanhoeffen 1914

• Main Authors: Kaiser, Stefanie, Brandt, Angelika
• Format: Other/Unknown Material
• Language: unknown
• Published: 2007
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Isopoda; Nannoniscidae; Austroniscus; Austroniscus ovalis; Weddell Sea; Weddell
• Online Access: https://zenodo.org/record/5688741; https://doi.org/10.5281/zenodo.5688741

Austroniscus ovalis Vanhoeffen, 1914 (Figs 10–11) Material examined Paratype: 1 Ψ (1.9 mm), E­Antarctica, Gauss­Station, 70–385 m, Museum für Naturkunde, Berlin, Nr. 17681. Other material: 3 Ψ (1 preparatory, 2 for SEM), eastern Weddell Sea, 71 ° 18.61`S, 013° 56.12`E – 71 ° 18.73`S, 013° 56.12`E, PS ANT XXI/ 2, Station 232–1, 910 – 899.6 m, ZMH K– 41123. Diagnosis Anterior margin of cephalothorax strongly concave. Pereonite 1 not frontally directed, lateral margins rounded; with 2 spine­like appendices inserting ventrally. Description Habitus of paratype female (Figs 10 A, 11 A): considerably broadened and flattened. Body about 1.9 mm length, 1.5 times longer than wide. Coxae not visible in dorsal view. Pereonites 2–4 with strongly projected laterofrontal margins, with a small spine apically. Lateral margins of pereonite 1 rounded, with two spine­like appendices inserting ventrally on both sides of cephalothorax and tipped with a small spine, appendices distinctly separated from cephalothorax by a suture line. Pereonites 2–7 of similar size, Pereonite 4 widest, pereonite 1 width 0.6 times pereonite 4 width. Pleotelson (Fig. 10 B) length 0.3 times body length, twice as long as wide; width 0.9 times pereonite 4 width¸ anterior margin slightly concave, posterior margin strongly rounded. Uropods not projecting above posterior margin (Fig. 11 B). Cephalothorax (Figs 10 A, 11 C–D): free, 1.7 times longer than wide, length 0.4 times body length (measured medially), width half of pereonite 4 width, with a well developed rostrum, deeply vaulted. Antennae inserting frontolaterally in a deep fold between rostral crest and anterolateral triangular projections; each fold medially with a single spine. Posterior margin of cephalothorax slightly rounded. Antennula (Fig. 10 C) with 6 articles. Article 1 as long as article 2, 1.3 times longer than wide. Article 2 about 4.6 times longer than wide, with 3 long broom setae and 2 small simple setae distally. Articles 3–6 together as long as article 1, each of similar size. Articles ...