Girish S, Saidapur S K
Department of Zoology, Karnatak University, Dharwad 580 003, India.
J Biosci. 2003 Jun;28(4):489-96. doi: 10.1007/BF02705123.
Effects of density and kinship on growth and metamorphosis in tadpoles of Rana temporalis were studied in a 2 4 factorial experiment. Fifteen egg masses were collected from streams in the Western Ghat region of south India. The tadpoles were raised as siblings or in groups of non-siblings at increasing density levels, viz. 15, 30, 60 and 120/5 l water. With an increase in density level from 15 to 120 tadpoles/5 l water, duration of the larval stage increased and fewer individuals metamorphosed irrespective of whether they belonged to sibling or non-sibling groups by day 100 when the experiments were terminated. The size of individuals at metamorphosis declined significantly with increase in the density of rearing. However, at higher densities (60 and 120 tadpoles/5 l water) sibling group tadpoles performed better compared to mixed groups and took significantly less time to metamorphose. Also, more individuals of sibling groups metamorphosed compared to non-sibling groups at a given density. Mixed rearing retarded growth rates, prolonged larval duration resulting in a wider spectrum of size classes, and lowered the number of individuals recruited to terrestrial life. The study shows that interference competition occurred more strongly in cohorts of mixed relatedness than in sibling groups.
在一项2×4析因实验中，研究了密度和亲缘关系对颞蛙蝌蚪生长和变态的影响。从印度南部西高止山脉地区的溪流中收集了15团卵块。蝌蚪以同胞或非同胞群体的形式饲养，密度逐渐增加，即每5升水15、30、60和120只。随着密度水平从每5升水15只蝌蚪增加到120只，幼虫阶段的持续时间增加，到实验结束的第100天时，无论属于同胞组还是非同胞组，变态的个体都减少了。变态时个体的大小随着饲养密度的增加而显著下降。然而，在较高密度下（每5升水60和120只蝌蚪），同胞组蝌蚪的表现优于混合组，变态所需的时间明显更短。此外，在给定密度下，同胞组变态的个体比非同胞组更多。混合饲养会减缓生长速度，延长幼虫期，导致体型类别范围更广，并减少进入陆地生活的个体数量。该研究表明，与同胞组相比，混合亲缘关系的群体中干扰竞争更为强烈。
