PMC

Evolutionary patterns in photosynthetic activity and host use in the Sacoglossa. Information on host algae was taken from Händeler & Wägele [], Händeler et al. (unpublished data), Teugels et al. [], Trowbridge []; Krug et al. [] and authors' data. Empty square: no-functional chloroplast retention, blue square: functional short-term chloroplast retention, green star: functional long-term chloroplast retention.

Representative sacoglossans on their host algae. Approximation of length is given. (A) Costasiella cf. kuroshimae on Avrainvillea erecta (Lizard Island, Great Barrier Reef; 1 cm), (B) Elysia spec. 5 found affiliated with Chlorodesmis fastigiata (Lizard Island, Great Barrier Reef; 1 cm), (C) Ercolania kencolesi inside of Boergesenia cf. forbesii (Lizard Island, Great Barrier Reef; 0.5 cm), (D) Lobiger viridis on Caulerpa spec. (Lizard Island, Great Barrier Reef; 0.5 cm), (E) Bosellia mimetica on Halimeda tuna (Mediterranean Sea; 1 cm).

Phylogeny of Sacoglossa. A Bayesian analysis was performed on concatenated partial gene sequences of the nuclear 28S, the mitochondrial 16S, and the mitochondrial coxI (1^st and 2^nd positions only) loci. Shown is a 50% majority-rule consensus tree generated from the post-burn-in tree sample. Numbers above branches are posterior probability support, black dot: posterior probability = 100, black triangle: posterior probability = 95 - 99.

Yield values (PAM measurements) of Costasiella cf. kuroshimae compared to Plakobranchus ocellatus. Y is the yield value of chloroplasts' photosynthesis that has been measured every day after capture of animal. Y is plotted against the days of starvation. Trendlines are calculated in Excel. In every figure the species with the longest measured ability of chloroplasts' function, Plakobranchus ocellatus, is shown as reference. Black trendline indicates no functional retention. Trendlines of species with long-term retention are green. Standard deviation and mean values are given.

Yield values (PAM measurements) of the genera Bosellia and Thuridilla compared to Plakobranchus ocellatus. Y is the yield value of chloroplasts' photosynthesis that has been measured every day after capture of animal. Y is plotted against the days of starvation. Trendlines are calculated in Excel. In every figure the species with the longest measured ability of chloroplasts' function, Plakobranchus ocellatus, is shown as reference. Trendlines of species that had short-term retention are blue. Trendlines of species with long-term retention are green. For better clarity standard deviation and mean values are not included.

Yield values (PAM measurements) of the genus Elysia compared to Plakobranchus ocellatus. Y is the yield value of chloroplasts' photosynthesis that has been measured every day after capture of animal. Y is plotted against the days of starvation. Trendlines are calculated in Excel. In every figure the species with the longest measured ability of chloroplasts' function, Plakobranchus ocellatus, is shown as reference. Black trendlines indicate no functional retention. Trendlines of species that had short-term retention are blue. Trendlines of species with long-term retention are green. For better clarity standard deviation and mean values are not included.

Representative sacoglossans showing habitus typical of major plakobranchacean clades. Approximation of length is given. (A) Cyerce nigricans on Chlorodesmis fastigiata (Lizard Island, Great Barrier Reef; 4 cm), (B) Polybranchia orientalis (Lizard Island, Great Barrier Reef; 2 cm), (C) Elysia ornata (Lizard Island, Great Barrier Reef; 2 cm), (D) Elysia crispata on sediment (Dominican Republic; 4 cm), (E) Plakobranchus ocellatus (Lizard Island, Great Barrier Reef; 4 cm), (F) Elysia pusilla (Maldives; 1 cm), (G) Elysia tomentosa (Lizard Island, Great Barrier Reef; 1.5 cm) (H) Thuridilla carlsoni (Lizard Island, Great Barrier Reef; 2 cm). (I) Elysia viridis (Mediterranean Sea, animal placed on brown algae; 1,5 cm). (J) Thuridilla hopei (Mediterranean Sea, 2 cm).