Marine Flora and Fauna of the Eastern United States Platyhelminthes

8 NOAA Technical Report NMFS 121
Key to the Monogenea Parasitic on Marine Fishes
of the Eastern United States _
1 Haptor well developed, undivided and disklike, with or without hamuli; haptoral suckers and
clamps absent; anterior adhesive area usually with glands opening via head organs, bilobed sessile,
or disklike areas (see Fig. 3, A and B) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 2
1 Haptor divided, usually with 4 or more pairs of suckers or clamps, pedunculate or sessile, hamuli
present or absent; anterior region containing buccal suckers or weak oral sucker (see Figs. 2 and
4, A-D.) (Order Polyopisthocotylida) 39
2(1) Posterior attachment organ a pseudohaptor with numerous radiating rows of spines, larval haptor
with 16 marginal hooks, undeveloped, at posterior margin of pseudohaptor. Parasitic on skates
(Rajidae). . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. (Family Acanthocotylidae) Pseudacanthocotyla verrilli (Fig. 5)
2(1) Posterior attachment organ a haptor lacking radial rows ofspines. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. 3
3(2) Haptor distinctly muscular, disklike, with or without 1 or 2 pairs of hamuli and anterior sclerotized
accessory sclerites and lacking transverse supporting bars; anterior adhesive area disklike or
glandular (see Fig. 6) 4
Figure 5
Pseudacanthocotyla verrilli, ventral view.
Scale: 1 mm. Drawn from USNM 7175.