Cymothoidae Leach, 1814

Martin, Melissa B., Bruce, Niel L. & Nowak, Barbara F., 2016, Review of the fish-parasitic genus Cymothoa Fabricius, 1793 (Crustacea: Isopoda: Cymothoidae) from Australia, Zootaxa 4119 (1), pp. 1-72 : 4-5

Family Cymothoidae Leach, 1814

Remarks. This contribution concludes a series ( Martin et al. 2013, 2014a, b, 2015a, b) revising the buccalattaching genera of Cymothoidae from Australia. A key is provided to all the marine genera of buccal-attaching Cymothoidae , which is complemented by the keys given to the external-attaching genera ( Bruce 1987a, b, c, 1990) and the gill-attaching genera ( Bruce 1986, 1990).

Key to the marine buccal-attaching genera

This key is restricted to ovigerous female of the genera that are solely known to attach in the host’s buccal region. This group is not monophyletic as it includes Smenispa Özdikem, 2009 a genus which shows closest affinities to external-attaching genera such as Anilocra and Livoneca Leach, 1818 (see Bruce 1987a, 1990 for diagnoses) and Catoessa a genus of uncertain affinities (see Bruce 1990). The monotypic genus Tetragonocephalon Avdeev, 1975 is morphologically similar to Smenispa (based on the dorsal view of the cephalon, pereon and pleon shape) and as we are unable to find any characters to distinguish the two genera, Tetragonocephalon is not included in the key.

1. Cephalon posterior margin trisinuate; pereon and pleon strongly co-linear; brood pouch with posterior pockets, oostegites of coxae 6 forming most of the marsupium................................................ Smenispa Özdikem, 2009

- Cephalon posterior margin rounded or straight; pereon and pleon weakly co-linear; brood pouch without posterior pockets; oostegites arising from coxae 1–6, all forming the marsupium.................................................. 2

2. Pleotelson posterior margin subtriangular; body widest at pereonite 6........................... Olencira Leach, 1818

- Pleotelson rounded or subtruncate; body widest at pereonite 4 or 5.............................................. 3

3. Antennula longer than antenna; pereopod 5–7 basis without well-developed carina; pleon and pleotelson axially twisted (“rotated”) against the pereon............................................... Catoessa Schioedte & Meinert, 1884

- Antennula shorter than antenna; pereopods 5–7 basis with well-developed carina; pleon and pleotelson are not axially twisted against pereon....................................................................................... 4

4. Antennae thick and expanded; antennula bases contiguous; cephalon not or weakly immersed in pereonite 1............ 5

- Antennae slender; antennula bases narrowly to widely separated; cephalon deeply immersed in pereonite 1............. 6

5. Pereonite 1 anterolateral margins projecting forward, without slight recess, anterior margin concave.. Ceratothoa Dana, 1852

- Pereonite 1 anterolateral margins projecting laterally, with slight recess, anterior margin straight or convex.................................................................................... Glossobius Schioedte & Meinert, 1883

6. Body weakly vaulted; anterior margin of cephalon with distinct rostrum; anterolateral margins of pereonite 1 extending beyond rostrum, with prominent lobes...................................................... Lobothorax Bleeker, 1857

- Body strongly vaulted; anterior margin of cephalon without distinct rostrum anterolateral margins of pereonite 1 minute or reaching anterior margin of rostrum, without prominent lobes.................................................. 7

7. Body ovate, less than 1.5 times as long as greatest width; pleopods 3–5 without fleshy folds................................................................................................... Cinusa Schioedte & Meinert, 1883

- Body subparallel or weakly ovate, more than 1.5 times as long as greatest width; pleopods 3–5 with fleshy folds.......................................................................................... Cymothoa Fabricius, 1793