Tench

Body thickset, heavy, and laterally compressed, the caudal peduncle characteristically deep and short. Skin thickened, slimy; the scales small, embedded. Overall coloration olive-green, at times dark green or almost black, with golden reflections on ventral surface. Head triangular, eye orange-red, small; snout relatively long; interorbital broad; mouth terminal, small in size with thick lips and a pair of well-developed barbels, one at each corner of the mouth. Caudal fin with 19 rays (Ref. 2196). Diagnosed from other cyprinid species in Europe by the following characters: body golden greenish brown; one pair of barbel (maxillary); lateral line with 96-115 scales, small and deeply embedded; dorsal fin with 8-9½ branched rays; and anal fin with 6-9½ branched rays (Ref. 59043).

Tench Reovirus Infection. Viral diseases

Pseudocapillaria Infestation 1. Parasitic infestations (protozoa, worms, etc.)

Males reproduce at 2-3 years and females at 3-7 years. Spawning happens, depending on latitude, between May and September, at temperatures of 19 20°C. Lays numerous sticky green eggs on plants or on the botton every 1 5 days for 2 months. Incubation at 20°C lasts 3 days. Larvae remain attached to the plants for several days until the vitellus is used up. Egg size 0.8-1.0 mm, larval length at hatching 4-5 mm.

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.

Dorsal spines (total): 4; Dorsal soft rays (total): 8 - 9; Anal spines: 3 - 4; Analsoft rays: 6 - 8; Vertebrae: 39 - 41

Inhabits warm lakes and pools with weed and mud bottom. Tolerant of low oxygen saturations (Ref. 30578, 44894). Occurs in still or slow-flowing waters, often among dense vegetation (Ref. 44894). In winter, it stays in the mud without feeding itself (Ref. 30578). Omnivorous. Feeds on bottom invertebrates and aquatic insect larvae. Young also feed on algae (Ref. 1998, 44894). Breeds in shallow water among dense vegetation, laying numerous sticky green eggs. After hatching the larvae remain attached to the plants for several days. Used as a fodder fish for bass (Ref. 7248).

Typically found in shallow, densely vegetated lakes and backwaters. Often overwinters buried in mud. Larvae and juveniles confined to dense vegetation (Ref. 59043). Adults inhabit warm lakes and pools with weed and mud bottom. Tolerates low oxygen saturations (Ref. 30578, 44894). Feeds on detritus, benthic animals and plant materials. Adult often prey mainly on molluscs. Spawns among dense vegetation in still water (Ref. 59043). Used as a fodder fish for bass (Ref. 7248). Utilized fresh and frozen; eaten pan-fried, broiled, and baked (Ref. 9988). Popular with amateur sport fishers. Its flesh is highly esteemed (Ref. 30578). Locally under threat due to river engineering (Ref. 59043). Reported to reach a maximum length of 84 cm TL (Ref. 5723).

fisheries: commercial; aquaculture: commercial; gamefish: yes; aquarium: public aquariums