Resumen de Edad, crecimiento y reproducción de la Boga de Río (Chondrostoma polylepis polylepis Stein, 1865) en el embalse de Pinilla (Río Lozoya): N.º 317

Javier Lobón Cerviá, Benigno Elvira Payán

• The authors deal with some aspects of the biology of the Iberian Nase-Carp (Chondrostoma polylepis polylepis Stein.) from "Pinilla" reservoir (Lozoya River, Tagus basin). Scales of 284 specimens were used for age determinations. Females grow faster than males and they live two years more. Spawning occured during last May and June thought some specimens may spawn in July. Elaboration of gonads occured between September and May. The condition of mature specimens is affected by gonads cycle. The fecundity id represented by the formulas:

  Log N.º E = - 3,5743 + 3,1112 Log L_t (GM regression) .

  Log N.º E = - 1,2596 + 2,1374 Log L_t (least square) .

  Approximately half of population attains sexual maturity at 3 + age class. Minimum harvestable size is 215 mm (145g). Algae is the main item of food.