Effects of color variation and physiological state on ascidian microbiomes.

Ascidians, known for their color variation, host species-specific microbial symbiont communities. Some ascidians can also transition into a nonfiltering (resting) physiological state. Recent studies suggest that the microbial symbiont communities may vary across different physiological states and color morphs of the host.

Distinct microbial communities in an ascidian-crustacean symbiosis.

Ascidians are marine invertebrates known to occasionally host symbiotic crustaceans. Although the microbiomes of both ascidians and free-living crustaceans have been characterized, there is no documentation of microbial communities in an ascidian-crustacean symbiosis. Samples of the solitary ascidian Ascidia sydneiensis and ambient seawater were collected in Belize.

Prokaryotic symbiont communities in three ascidian species introduced in both Ireland and New Zealand.

Ascidians or sea squirts are among the marine taxa with the most introduced species worldwide. These animals have a suite of biological characteristics that contribute to their successful establishment, including long reproductive seasons, rapid growth rates, and resistance to pollution. Here, we sequenced a fragment of the 16S ribosomal RNA gene to characterize symbiont diversity and host-specificity in the solitary species Syela clava and Ascidiella aspersa, and the colonial species Didemnum vexillum.

Diversity and abundance of native and non-native ascidians in Puerto Rican harbors and marinas.

Ascidians are an ideal taxon to study invasion processes: they require anthropogenic introduction vectors for long-distance dispersal, are easy to collect and monitor, and are abundant on artificial substrates. In March 2019 we surveyed 11 harbors around Puerto Rico and recorded 47 ascidian species. Eleven of these were only identified to the genus level or above based on morphological or genetic characterization.