Description of Trichodina hippoglossi n. sp. from farmed Atlantic halibut larvae Hippoglossus hippoglossus

Abstract

A new species of Trichodina, T hippoglossi n. sp., collected from skin and fins of farmed Atlantic halibut Hippoglossus hippoglossus (L.), is described. Heavy infections were first evident after a temperature rise from 12 to 18C. The most infected specimens were easy to detect due to increased mucus production, which gave the larvae a greyish skin colour. 7 hippoglossi is relatively large, 78.5 r 6.9 pm (mean t SD; range 65.9 to 89.6 pm), with a denticle ring compris~ng 28 (mode; range 26 to 30) denticles and wlth a denticle span of 17.6 r 1.1 pm (mean t SD, range 15 7 to 19.2 pm). In silver-impregnated fully grown specimens, a prominent clear central disc 1s present KEY M'ORDS. Atlantlc halibut Trichodina hippoglossi . New species . Descl