Re: Calliopaea bellula - Ercolania cf. viridis & eggs

April 2, 2009
From: Kathe Rose Jensen

Concerning message #22386:

Dear Bill,

Sorry I missed the egg mass question. However, egg masses of Ercolania nigra are highly variable. Sometimes they will produce 2-3 small egg masses per day shaped like those in Marina's pictures [#22366]. Sometimes one large egg mass every second day, shaped like the one in Alexander's picture from the Black Sea [message #8300 ].

I have never noticed orange tips of the cerata, so I think that must be a photographic illusion. White tips are sometimes present as are the tiny white dots (dermal mucus glands?).

At one time Kerry Clark also thought that there were two species of "Ercolania funerea" in Florida - also with different egg masses, and I know there are two species of "Ercolania boodleae"/ "E. emarginata " in Hong Kong - one with white tips and one with orange or white tips of the cerata. I tried to do fertility experiments in the lab. and one specimen didn't want to copulate with any others until I got a partner that matched. But since I couldn't tell them apart externally, I don't know which of the preserved specimens are which species. So maybe Marina and others should try to observe copulation between green and dark specimens. It would certainly help if we could just separate them on coloration.

Best wishes,
Kathe

krjensen@snm.ku.dk

Jensen, K.R., 2009 (Apr 2) Re: Calliopaea bellula - Ercolania cf. viridis & eggs. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22387

Dear Kathe,

I know there is evidence that some species change development types, but these two egg masses are so different that I find it difficult to believe they are produced by the same species. It's not whether the black and green animals are the same species - if the egg masses do reflect two species then both species have a green and black form. Certainly the series of photos Marina has sent us show that the species laying the sausage-shaped egg masses ranges from black to green. I remember looking at the old literature when Alexander sent his Black Sea photos and I am happy with the identification of that animal as Costa's E. viridis [=E. funerea]. If Marina's is a different species, there seem to be about 6 names for Ercolania and Ercolania-looking species which have been named from the Mediterranean and nearby waters. Perhaps one of those will need to be resurrected. Clearly stage 1 would be to see if Marina's animals ever lay Alexander-type eggs.

I think I will keep Marina's animals on an Ercolania cf viridis page so that the two 'forms' don't get even more confused

Best wishes,
Bill Rudman

Rudman, W.B., 2009 (Apr 2). Comment on Re: Calliopaea bellula - Ercolania cf. viridis & eggs by Kathe Rose Jensen. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/22387

Factsheet

Ercolania cf viridis

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