The reproductive traits of brown trout (Salmo trutta fario L.) from the Yadong River, Tibet

Abstract

Some key aspects of the reproductive strategy of the brown trout (Salmo trutta fario L.) in the Yadong River, Tibet, including spawning season, age at sexual maturity, fecundity and egg size, have been studied. The majority of the samples were less than 215 mm and age ranged from 1 to 4 in both sexes, indicating that the majority of the fish were younger and the pressure by overfishing was high. The spawning periodicity was determined to be between the end of October and January, mainly in November and December. The ratio of male to female brown trout population (1.29:1 with P>0.05) suggested no sex significant differences, although males were significantly more abundant than females in October (P<0.0001) on monthly basis. Age and size of males and females at maturity was different and males matured earlier than females. Fecundity was markedly correlated with their body weight (P< 0.001, r = 0.9255), standard length (P <0.01, r = 0.8879), and gonad weight (P<0.001, r=0.9366).The mean size of mature eggs in the spawning season was: 4.0±0.45 mm and tended to increase along with the female spawners size (P <0.001, r= 0.9641). Further researches about the brown trout population in the Yadong River should be conducted on issues such as artificial reproduction, culture, conservation, management, and restocking.

Effects of dietary protein at two lipid levels on growth, gonadal development, body composition and liver metabolic enzymes of brown trout (Salmo trutta fario) broodstock

“…This species was probably introduced into the Yadong River, Tibet, more than a hundred years ago; however, it was first reported only in 1962 (Zhang & Wang, 1962). Recently, wild populations of this species have decreased owing to river pollution, unauthorized fishing, and destruction of natural spawning sites (Hao et al, 2009). Furthermore, the Yadong River is listed as a protected region for aquatic animals of economic importance (Peng, 1995).…”

Growth and sperm quality in rainbow trout Oncorhynchus mykiss (Teleostei: Salmonidae) during the reproductive season

“…No obstante lo anterior, la producción de semen no se vio afectada, ya que la energía proporcionada por el alimento fue destinada para asegurar la reproducción, tal como se reporta en Wootton (1999) y Hao y Chen (2009), quienes mencionan que la energía adquirida del alimento se reparte entre el crecimiento y supervivencia, y al entrar en etapa reproductiva gran parte de ésta energía se destina a los diversos procesos de maduración sexual.…”

High above the mountains, far across the sea—Aquaculture is helping to eradicate poverty in one of the world's most remote areas

“…of Yadong trout succeeded, boosting the wild resource reservation and farming of this species. 3 In the following years, experts in fish breeding, disease control, nutrition and industrial farming from the Shanghai Ocean University and Yellow Sea Fisheries Research Institute were invited to participate in the large-scale farming of Yadong trout, providing support for technical development and training. 4 Till date, a government-owned industrial park (Figure 1) and 46 farmer-owned riparian ponds have been built.…”