条纹短攀鲈的交配习性和筑巢生境

条纹短攀鲈栖息于静止、植被茂密、靠近稻田和池塘边缘的浅水中。本文研究了它在泰国稻田和小池塘两种生境中的繁殖特征。与池塘相比,稻田筑巢地的pH值、溶解氧的含量和温度较高,而电导、溶解的固体物浓度较低,水也较浅。稻田中的种群密度低于池塘。雄性个体的体重和体长均大于雌性个体,且其体重与体长和体宽正相关,但雌性个体的体重仅与体长正相关;泡巢的面积与雄性个体的体长和重量均不相关。繁殖期间,条纹短攀鲈雌、雄个体交尾多次。每次交尾产卵3.74±1.02(Mean±SD)粒,每个繁殖季节交尾84±12.97次;在一个持续178±51.17min的产卵时段里,条纹短攀鲈平均产卵314±109.77粒。鱼苗孵化需30.75±0.55h,2日龄个体的大小平均为3.21±0.29mm。

Mating habits and nesting habitats of the croaking gourami Trichopsis vittata

Croaking gouramis Trichopsis vittata were investigated in the two types of habitats in which they occur in Thailand: rice paddy fields and small ponds. Croaking gouramis inhabit shallow standing water with dense vegetation near the margin of both habitats. Nest sites in rice paddies were higher in pH, dissolved oxygen, and temperature but lower in specific conductance, total dissolved solids and water depth than in small ponds. Population densities of croaking gouramis were lower in rice paddies than in small ponds. Males were heavier and bigger than females. There were positive correlations between male weight and body length and width, whereas female weight was positively correlated only with body length. There was no correlation between the bubble nest area and the male body length and weight. Male and female embraced many times during mating. There were (Mean ± SD) 3.74 ± 1.02 eggs per embracement, 84 ± 12.97 embracement/spawning, and 314 ± 109.77 eggs/spawning with a spawning duration of 178 ± 51.17 min. Fish larvae hatched within 30.75 ±0.55 h and 2-day old fry's sizes were 3.21 ± 0.29 mm.