Extra-capsular yolk bodies
February 27, 2000
From: Scott Johnson
Hi Bill,
In response to your request for photos of the extra-capsular yolk bodies of some Chromodoris species, I went through all my nudibranch photos with no real success. I thought I had some, but perhaps I did not. I did most of my looking at egg masses at Enewetak in the early 80s, and the way I collected eggs for examination, in plastic tubs floating in flow-through sea tables, did not really lend itself to my low tech, Nikonos extension tube photography. I'll try to get some more and do a better job. In the meantime, here's a photo of the closest I have, an old and deteriorating egg mass of Chromodoris albopunctata. The orange blobs in the gelatinous matrix are yolk bodies left over after the larvae had left. C. albopunctata is unusual in its yolk, however. While other Chromodoris species that possess extra-capsular yolk have it distributed as a small orange cap next to each ovum, in C. albopunctata it forms larger but variably sized orange chunks scattered intermittently throughout the egg mass.
Boucher (1983) has drawings of both the "standard" cap-like yolk bodies and the scattered blobs of C. albopunctata.
Reference:
•Boucher, L.M. 1983. Extra-capsular yolk bodies in the egg masses of some tropical Opisthobranchia. Journal of Molluscan Studies, 49(3): 232-241.
Scott
johnson@kmr.ll.mit.edu
Johnson, S., 2000 (Feb 27) Extra-capsular yolk bodies. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1972Thanks Scott,
I thought it would be useful for others to make observations if they knew what to look for. If you do see some photogenic egg masses in the future I'm sure you'll keep the Forum in mind.
Bill Rudman.
