chapter  4
15 Pages

Knowing your way round a fish

WithMark Everard, Jack Perks

The cone cells of the eyes of cyprinid fish are well developed, conferring them elaborate colour vision. Sensitivity to water pressure varies amongst fish species according to their adapted life habits and ecological needs, the day-active perch that hunts substantially by sight having a less developed lateral line than species remaining or predominantly active by night. Proprioceptors, or stretch receptors, are also embedded in the body tissues, both regulating swimming activity as well as governing buoyancy as gas in the swim bladder expands under reduced pressure as the fish rises in the water column. The initially large eyes of young common bream species do not develop at a rapid rate, resulting in adult fish with reduced reliance on vision but enhanced taste systems, suiting them to life browsing on invertebrate prey buried in soft sediments.