Aggregata andresi n. sp. (Apicomplexa: Aggregatidae) from the ommastrephid squid Martialia hyadesi in the SW Atlantic Ocean and some general remarks on Aggregata spp. in cephalopod hosts

Abstract

A new species of coccidian, Aggregata andresi, is described from the digestive tract of the flying squid Martialia hyadesi, an ommastrephid squid that lives in cold subantarctic waters in the Southwest Atlantic. Gamogonic and sporogonic stages were observed in the digestive tract of 96.5% studied hosts. Oöcysts were ovoid to subspheroid in shape, 170–590 μm in length and 200–530 μm in width. Each oöcyst contained approximately 45,000 sporocysts. Sporocysts measured 9.5–10 μm in length and 8–8.5 μm in width. The surface of the sporocyst wall was smooth and the cyst wall thick. Each sporocyst contained three sporozoites measuring 16–20 μm in length and 2–2.5 μm width. A. andresi is the second species of Aggregata to be reported from a nerito-oceanic cephalopod host.