The family Didemnidae includes 20% of all known ascidians with six genera in the Atlantic. Here, we describe five new species in the Didemnidae from central coastal Brazil. Four species are in the genus Didemnum and were found in Bahia (D. aurantium, D. flammacolor, D. lambertae, D. longigaster), while one Diplosoma (D. citrinum) was found both in Bahia and Espírito Santo.

The process of allorecognition consists of an ability to discriminate self from non-self. This discrimination is used either to identify non-self cells and reject them ("non-self histocompatibility") or to identify self cells and reject them (as in the avoidance of self-fertilization by hermaphrodites ("self incompatibility"). The molecular basis governing these two distinct systems has been st...

The solitary ascidian Microcosmus exasperatus is globally distributed in tropical and sub-tropical waters. In the Mediterranean it is considered an invasive species introduced through the Suez Canal, with a restricted distribution in the eastern basin. In order to understand the potential of this species to establish sustainable communities at additional sites in the Mediterranean, we studied i...

The undamaged test of a range of aplousobranch ascidian species is shown to be chemically neutral. Acid is generated by surface test cells following cell lysis and is rapidly neutralised in the presence of calcareous test inclusions and/or sea water. Neither the capacity to produce acid nor the presence of vanadium prevents predation on ascidian species in the field.

Little is known about the ascidian fauna of Pacific Panama. Ascidian surveys were conducted in the southern Gulf of Chiriquí on the Pacific coast of Panama in January 2008 and 2009. Surveys along linear transects at 2-3 m depth (snorkel, 2008) and 5 and 12 m depth (SCUBA, 2009) were conducted at multiple sites within a chain of islands extending out from the mainland. Twelve different ascidian ...