9. THE CLASS CRUSTACEA
293
Pathology. Odlaug (1946) has demonstrated that Olympia oysters,
Ostrea lurida, when infected with M . orientalis, have a lower condition
index (a measurement of fatness) than uninfected ones. Similarly,
Chew et al. (1964) have shown that M . orientalis reduces the condition
index in Crassostrea gigas."
I n the area of histopathology, Sparks (1962) has shown that metaplasia occurs in the gut of Crassostrea gigas when parasitized by this
copepod (see Chapter 4, Section 11, A, 6).
2
FIGS. 190-193. Mytilicola spp. (190) Adult female M . orientalis, ventral view; (191)
adult male M . orientalis, ventral view (redrawn after Mori, 1935); (192) adult
female M . porrecta, ventral view; (193) adult male M . porrecta ventral view
(redrawn after Humes, 1954b).
3. Mytilicola porrecta Humes, 1954. (Figs. 192 and 193)
(Order Cyclopoida; family Clausidiidae)
The third species of Mytilicola, M . porrecta, is also known to be a
It was described by
parasite of commercially important molluscs.
* See note on p. 390.