Commensal and parasitic copepods (Arthropoda: Crustacea: Copepoda) of two common species of sea squirts, Phallusia mamillata and Ciona intestinalis have been investigated in the sea of Taranto (southern Italy).
A total of 2590 specimens of copepods were collected (five families, eight genera and 13 species). The sex ratio on 2582 specimens was 1228 males (47·56%) to 1354 females (52·44%).
The species were identified by the hosts in which they were found, their sex ratio host by host, and the specific variability and affinity analysis by means of the Sørensen index and the diversity index by means of the Shannon application.
Some species of copepods have been found for the first time as in Ciona intestinalis (Hermannella rostrata) and in Phallusia mamillata (Notodelphys canui, Doropygus pulex, Pachypygus gibber, Notopterophorus auritus, Lichomolgus albens, Hersiliodes latericia). The association Notodelphys canui–Doropygus pulex—Notopterophorus auritu–Lichomolgus albens is noted for the first time in the Mediterranean Sea.