Copepods associated with Phallusia mamillata and Ciona intestinalis (Tunicata) in the area of Taranto (Ionian Sea, southern Italy)

Commensal and parasitic copepods (Arthropoda: Crustacea: Copepoda) of two c ommon species of sea squirts, Phallusia mamillata and Ciona intestinalis ha ve 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 se x ratio host by host, and the specific variability and affinity analysis by means of the Sorensen index and the diversity index by means of the Shanno n application. Some species of copepods have been found for the first time as in Ciona int estinalis (Hermannella rostrata) and in Phallusia mamillata (Notodelphys ca nui, Doropygus pulex, Pachypygus gibber, Notopterophorus auritus, Lichomolg us albens, Hersiliodes latericia). The association Notodelphys canui Doropy gus pulex. Notopterophorus auritu Lichomolgus albens is noted for the first time in the Mediterranean Sea.