22. The development of Mazocraes Hermann 

 Just as all of the subsequent genera, the genus Mazocraes 



is characterized by the presence of special clamps on the attaching disc 

 which serve for the attachnnent of the animals. As has been indicated, 

 these clamps have a connplex structure because of the presence of a 

 large number of chitinous parts of systematic significance. The genus 

 Mazocraes (Fig. 24) is directly diagnosed as Mazocraeidae which have 

 4 pairs of clamps, 2 large middle hooks and 2 pairs of smaller hooks 



of different sizes on the 

 attaching disc. The basic difference 

 of this genus from the one closest 

 to it is the special structure of the 

 chitinous parts of the male copu- 

 latory organ. 



During our work on the 

 Caspian (Island of Sara, 1932 and 

 1955) and Black (Sebastapol, 1955) 

 Seas we often obtained early stages 

 of the development of M. alosae 

 Hermann- -typical parasite of 

 herring -type fishes. The free- 

 swimming larvae emerge from the 

 eggs on the fourth to the sixth day 

 They are strongly elongated in 

 length, cigar -shaped with a weakly 

 delineated attaching disc. Their 

 length is about 0, 2 mm their 

 width is about 0. 08 mm. The 

 ciliary covering is distributed along 

 the sides of the body extending onto 

 the dorsal eind ventral surfaces. It 

 Mazocraes alosae Hermann extends from within a short distance 



of the anterior end of the body to the 

 anterior edge of the attaching disc 

 and then is located on a cone-shaped 

 growth beyond the disc. The lateral 



p. 195 



01 KM 



Fig. 222. 



free -swimming larva in ventral (on 

 the left) and dorsal (on the right) 

 views. 



zones of the ciliary epithelium are divided into five cells on each side of 

 the body. Between the cells there are some small but clearly visible 

 sections which are free of ciliary epithelium. The posterior zone is 

 divided into two groups between which lies a relatively large section 

 which forms the rovmded apex of the posterior cone which is free of cilia. 

 The anterior end of the larva is slightly rounded and behind it is located 

 a glandular depression slightly divided into two halves. On each side of 

 it (the depression, nobis) and somewhat behind are two pairs of offering 

 ducts of the head glands. Approximately between the first and second 



212 



