Echinothambematidae, Menzies, 1956

Just, Jean, 2025, Vemathambema falciclava sp. nov. from south-eastern Australia, first Indo- Pacific record of the genus, with a review of diagnoses in the family (Isopoda, Asellota, Echinothambematidae), Zootaxa 5725 (1), pp. 135-142 : 136

Key to genera and species in Echinothambematidae

1 Lateral margins of most pereonites extended in irregular cone-shape with 1 or 2 apical spine setae; head and pereonite 1 not fused……… Echinothambema ........................................................................... 2

- Lateral margins of pereonites irregularly rounded without extensions; head and pereonite 1 fused……… Vemathambema ... 3

2 Antennula article 1 with distal projection extending beyond article 2; pereonites 1–7 lateral projection with 1 apical seta, pereonite 2 with 1 additional posterodistal seta; pleotelson lateral margins with seta on fused first pleonite, otherwise smooth.................................................................................. E. ophiuroides

- Antennula article 1 cylindrical without projection; pereonites 1 and 4–7 with one terminal seta on lateral projections, pereonites 2 and 3 with two terminal setae; pleotelson lateral margins with 3 stout setae.............................. E. aculeata

3 Antennula article 1 extended into upward curved sickle-shaped spine............................ V. falciclava sp. nov.

- Antennula article 1 cylindrical........................................................................... 4

4 Pereonites 2–4 middle dorsum vaulted across the segment overreaching other parts of the margin, distally rounded; opercular field covering approximately 80 ( ♀) and 90 ( ♂) % of entire ventral pleotelson area.................... V. argentinensis *

- Pereonites 2–4 not transversely vaulted or laterally expanded, individual margins slightly different, 2 with small anterior point, 3 rounded, 4 angular in middle; opercular field covering approximately 65 ( ♀) and 75 ( ♂) % of entire ventral pleotelson area........................................................................................ V. elongata