Thalassoalaimus

Martelli, Antonela, Russo, Virginia Lo, Villares, Gabriela & Pastor De Ward, Catalina T., 2017, Two new species of free-living marine nematodes of the family Oxystominidae Chitwood, 1935 (Enoplida) with a review of the genus Thalassoalaimus de Man, 1893 from the Argentine coast, Zootaxa 4250 (4), pp. 347-357 : 356

Key to all known species of genus Thalassoalaimus

(Based on male characteristics)

1. Tail without pointed tip....................................................................... T. brasiliensis

- Tail with pointed tip...................................................................................2

2. More than 2 precloacal organs................................................................... T. pacificus

- Two precloacal organs..................................................................................3

3. Cephalic setae more than 1/2 of the corresponding diameter....................................................4

- Cephalic setae less or equal than 1/2 of the corresponding diameter..............................................5

4. Gubernaculum more than 1/2 spicule length..................................................... T. nestori sp. n.

- Gubernaculum less than 1/2 spicule length..................................................... T. macrosmaticus

5. Cephalic setae configuration: 6+6+4.......................................................................6

- Cephalic setae configuration: 6+4+4.......................................................................7

6. Cephalic setae less than 3 times the cephalic diameter from anterior end............................. T. mediterraneus

- Cephalic setae more than 3 times the cephalic diameter from anterior end................................... T. tardus

7. c’ less than 2................................................................................... T. lissus

- c’ greater than 2.......................................................................... T. septentrionalis