Spinitectus

Arai, Hisao P. & Smith, John W., 2016, Guide to the Parasites of Fishes of Canada Part V: Nematoda, Zootaxa 4185 (1), pp. 1-274 : 107

Key to species of Spinitectus

Preamble: Spinitectus cristatus Railliet & Henry, 1915 , from various species of hake Urophycis in the Atlantic, is recorded here for the sake of completeness. As discussed below, the description is inadequate, and the species cannot be included in the following key.

1 Buccal cavity less than half length of “head”; vagina directed anteriorly; excretory pore between the 4th and 5th spine rows. 2

- Buccal cavity at least as long as “head”; vagina directed posteriorly; excretory pore between the 6th and 7th or 8th and 9th spine rows............................................................................................... 3

2 Circlets and semicirclets of spines reach near anus in females; ratio of oesophagus to body length 1:4 to 1:5; right spicule with heel-like barb................................................................................ S. acipenseri

- Spines not reaching near anus in females; ratio of oesophagus to body length 1:2 to 1:3; right spicule lacks heel-like barb............................................................................................... S. gracilis

3 Excretory pore between the 8th and 9th spine rows; spines <0.015 long.................................... S. carolini

- Excretory pore between the 6th and 7th spine rows; spines> 0.020 long............................... S. macrospinosus