FISHERY BULLETIN: VOL. 76, NO. 1 



coccidians. The only group considered here are the 

 gregarines of penaeids. Gregarines, in general, 

 are not highly pathogenic to their hosts. There- 

 fore, information presented here is brief and the 

 reader is referred to referenced works for details. 



Class Telosporea Schaudinn 1900 

 Subclass Gregarinia Defour 1828 

 Order Eugregarinida Leger 1900 

 Family Cephaloidophoridae Kamm 1922 

 Cephalolobus penaeus Kruse 1959 



This species attaches to chitinous walls and 

 terminal lappets of the stomach filter in Penaeus 

 aztecus andP. duorarum (Figure 11). Usually the 

 attached stage is a trophozoite consisting of a pri- 

 mite with an anterior protomerite division that is 

 modified into a holdfast organ. The single nucleus 

 is in the center of the primite (Figure 11). The 

 primite, including the protomerite, is from 100 to 

 200 /xm long. Often attached to the primite pos- 

 teriorly will be 1 or 2 satellites (young tropho- 

 zoites). Spores, sporozites, and cysts have not been 

 observed. Overstreet (1973) reported this species 

 in P. setiferus from Louisiana, extending its range 

 from Florida as previously reported. I have ob- 

 served this species in pink shrimp occasionally 

 from Pensacola, Fla. This gregarine apparently 

 has no harmful effect on the shrimp host. It may be 

 possible that large numbers attached to the filter 

 apparatus of the host could interfere with filtra- 

 tion of particles bound for the hepatopancreatic 

 ducts or passing through the stomach. 



Cephalolobus sp. Feigenbaum 1975 



This form, reported from Penaeus brasiliensis, 

 utilizes the stomach filter as position of attach- 

 ment within host. Trophozoites consist of protom- 

 erite and deutomerite separated by a septum. As 

 in C. penaeus, the anterior end is modified into a 

 holdfast organelle. This species has been reported 

 in shrimp only from Biscayne Bay, Fla., and dif- 

 fers from C. penaeus in that the trophozoites occur 

 solitarily and are smaller (43-100 /xm long) than 

 those of C. penaeus. 



Family Porosptjridae Labbe 1899 

 Nematopsis penaeus Sprague 1954 



This species has been reported from brown, 

 pink, and white shrimps. It is found in the intesti- 

 nal tract. Figure 12a, b show specimens of 



12 



Nematopsis from the gut of a pink shrimp. These 

 may be N. penaeus or N. duorari (see below). 

 Works by Sprague (1954, see footnote 3), Sprague 

 and Orr (1955), Kruse (1959, 1966), Button et al. 

 (1959), and Hutton (1964) give information on 

 hosts including the intermediate moUuscan hosts, 

 for A^. penaeus. Overstreet (1973) discussed the 

 prevalence and morphology of N. penaeus and 

 pointed out that syzygy is multiple with up to 

 seven trophozoites in line attached to one another 

 reaching a length of over 0.5 mm. Characters for 

 distinguishing A^. penaeus andN. duorari are size 

 of gymnospore and number of different molluscan 

 intermediate hosts. No pathogenesis is associated 

 with this form. 



Nematopsis duorari Kruse 1966 



This gregarine is restricted to the gut of pink 

 shrimp. Kruse (1966) attempted to transmit it to 

 brown and white shrimp, but could not. Figure 12a 

 shows an immature association of a trophozoite of 

 Nematopsis sp. in syzygy. Since two of the known 

 Nematopsis species of penaeids appear identical in 

 their trophozoite stages, no attempt will be made 

 here to identify the specimens in Figure 12 to 

 species. 



Nematopsis sp. Kruse 1966 



Kruse (1966) described, but did not name, this 

 species from concurrent infections ■w'lih.N. duorari 

 in pink shrimp in Florida. This form had smaller 

 gymnospores than did A^. duorari. 



Nematopsis brasiliensis Feigenbaum 1975 



This is a recently described species oi Nematop- 

 sis in a penaeid shrimp. Found in the intestine of 

 Penaeus brasiliensis, this species consists of both 

 individual trophozoites and syzygies of biassocia- 

 tions (two trophs). It has been described from Bis- 

 cayne Bay only. Hutton (1964) reported N. 

 penaeus from P. brasiliensis. However, Feigen- 

 baum (1973) believes that the species Hutton re- 

 ported asN. penaeus may have been N. brasilien- 

 sis. 



Subphylum Cnidospora Doflein 1901 

 Class Microsporea Corliss and Levine 1963 

 Order Microsporida Balbiani 1882 



Microsporida are highly pathogenic to shrimps 



