March 12, 2004
From: Bill Rudman
While preparing Marina's messages [12391, #12392] I tried, without success, to find a good illustration or photo of Elysia catulus to compare with E. serca.
I have included here a copy of the painting in Gould's description of E. catulus alongside on of Marina Pod specimens for E. serca from the Bahamas. The whitish markings on E. catulus seem to be identical to the markings on some of Marina's animals even though the background colour is very variable. Other authors have suggested that there is more melanin in northern populations of 'E. catulus' but some of Marina's animals show plenty of melanin in the Bahamas. I would strongly agree with Kathe Jensen's suggestion that E. serca and E. catulus are the same species.
PHOTO: Left: Placobranchus catulus 'East Boston specimen'. Gould, 1870. Pl. 17, fig. 249. Right: Great Exuma, Bahamas, Western Atlantic. Depth: 1m. Length: 4mm. February 03, 2004. Photo: Marina Poddubetskaia
• Gould, A.A. (1870). Report on the Invertebrata of Massachesetts. Wright and Potter: Boston. 524pp. Pl. 17, fig. 249.
• Marcus, Ev. (1972) Notes on some opisthobranch gastropods from the Chesapeake Bay. Chesapeake Science, 13(4): 300-317.