LIFE-HISTORY VARIATION OF POLYMORPHIC ARCTIC CHARR (SALVELINUS-ALPINUS) IN THINGVALLAVATN, ICELAND
LIFE-HISTORY VARIATION OF POLYMORPHIC ARCTIC CHARR (SALVELINUS-ALPINUS) IN THINGVALLAVATN, ICELAND
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DOI：
10.1139/f88-182
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发表时间：
1988-09-01
影响因子：
2.4
通讯作者：
LINDEM, T
中科院分区：
文献类型：
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作者：
JONSSON, B;SKULASON, S;LINDEM, T
冰岛Thingvalavatn的北极炭(Salvelinus Alpinus)表现出四种形态。小型底栖炭生长缓慢，渐近长度为13厘米，2-4年龄成熟。大型食水炭随年龄增长较快，且几乎呈直线增长。它们在3-11岁时成熟。食浮游生物和食鱼性木炭的初始生长速率更高，但食浮游生物木炭在20 cm处停止生长，食鱼性木炭在叉长30 cm时停止生长。它们分别在3-5岁和5-10岁成熟。与体节相比，食浮性和食鱼性的性腺指数和性腺能量的年分配均高于底栖类。结果表明，食鱼性和食浮游性字符属于同一个基因库；食鱼性字符可能是从生长最快的食浮游生物中招募而来的，开始以23厘米长的鱼为食。由于几个生活史变量以及遗传、产卵时间和取食栖息地的显著差异，底栖类变种可能属于不同的种群。这四种形态似乎是通过营养辐射在湖泊中区分出来的，但应该被认为是同种的。
The Arctic charr (Salvelinus alpinus) in Thingvallavatn, Iceland, exhibits four morphs. Small benthivorous charr grow slowly, have an asymptotic length of 13 cm, and mature at an age of 2-4 yr. Large benthivorous charr grow faster and almost rectilinearly with age. They mature at an age of 3-11 yr. Planktivorous and piscivorous charr have even higher initial growth rate, but planktivorous charr cease growing at 20 cm and piscivorous charr at a fork length of 30 cm. They mature at 3-5 yr and 5-10 yr of age, respectively. The gonadosomatic index and the annual allocation of energy into gonads relative to soma were higher for planktivorous and piscivorous than for benthiovorous charr. The results indicate that piscivorous and planktivorous charr belong to the same gene pool; piscivorous charr are probably recruited from the most fast-growing planktivorous individuals and start feeding on fish at a length of 23 cm. The benthivorous morphs may belong to different stocks due to significant differences in several life history variables as well as genetics, spawning time, and feeding habitat. The four morphs seem to be differentiated within the lake through trophic radiation, but should be considered as conspecifics.