First occurrence of the non-indigenous bryozoan Amathia verticillata (della Chiaje, 1882) at the Hab river mouth in Pakistan

Abstract

The bryozoan Amathia verticillata (Delle Chiaje, 1822), previously named Zoobotryon verticillatum, is herein recorded for the first time in Pakistan, extending its northern distribution limit in the Arabian Sea and Indian Ocean. This non-indigenous species was detected on oyster reefs, at the intertidal zone, in the Hab River Delta, Balochistan coast. After the initial detection of the species in March 2018, a more detailed survey at low tide detected several colonies in 48 sites at the Hab River Delta on 4 May, 2018. That area had been frequently monitored, so the presence of this taxon at large densities denotes a large dispersion in a short-time period. Boat traffic is intense around the Hab River Delta, suggesting that A. verticillata was introduced there through boat hulls or fishing nets. As Pakistan has been experiencing an increasingly important role in the global ship traffic, measures to monitor and prevent the transport of marine non-indigenous species should be urgently implemented.