The Differentiation of Coenurus species by Hook Measurements

Extract

Hook dimensions of Multiceps glomeratus show that the hooks are capable of reaching full adult size in the coenurus stage.

The available material showed that M. serialis hooks were slightly larger than those of M. glomeratus in the adult stage; in the coenurus stage the differences were not significant.

Statistically, the dimensions measuring the length of the blade of the hook are the most satisfactory.

There are significantly large variances in most cystic hook dimensions from one cyst to another, and from one scolex to another within a single cyst, but not from one group of scolices to another. It follows that in biometric work it is important to sample several scolices from each cyst, and several cysts of any one species, but that groups can be disregarded.

The variability of most hook measurements is in the region of 5%; i.e. the standard deviation is about 5% of the mean dimension.

The danger of extensive generalisation from limited data should be guarded against. Thus, while the species variance was significantly larger than the cyst variance in the case of adult hooks in the material available, it is quite possible that this would no longer have been the case if material from other sources had been available.