micro-branchiospine

one of a series of small dermal ossifications, each bearing 5-20 tiny lateral spines, located on the outer face of each gill arch except the first near the base of the gill filaments as in Tilapia (Cichlidae). They may sieve out phytoplankton or protect the gills from abrasion by fine particles. Micro-branchiospine-like structures are found in Centropomidae, Pomadasyidae and Gerreidae due to homoplasy