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Abstract. A test of the niche width variation hypothesis was conducted in the three Mediterranean littoral species of the family Trochidae: Monodonta turbinata, M. turbiformis and Gibbula richardi. Allozymic variation encoded by 26 gene loci was analyzed, and the levels of polymorphism (P), heterozygosity (H) and allele diversity per locus (A) were estimated and appear to support the niche-width variation hypothesis. The broad-niche species, M. turbiformis and G. richardi are more polymorphic and heterozygous than the relatively narrow-niche M. turbinata (P = 0.571; 0.731 and 0.417; H = 0.108; 0.116 and 0.078; A = 2.025; 2.489 and 1.965, respectively). 相似文献
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Genetic Relationships Among One Non-Endemic and Two Endemic Mediterranean Triplefin Blennies (Pisces, Blennioidei) 总被引：1，自引：0，他引：1
Gerard J. Geertjes Albert Kamping Wilke van Delden & John J. Videler 《Marine Ecology》2001,22(3):255-265
Abstract. Three triplefin blennies occur sympatrically in the Mediterranean Sea; Tripterygion tripteronotus and T. melanurus are endemic, whereas T. delaisi is also found in the Eastern Atlantic. Although very similar in morphology, ecology and behaviour, some striking differences exist among reproductive strategies. Several authors proposed hypotheses on the evolution of these species. In order to enhance insight into the genetic structure of this genus, an enzyme electrophoretic survey was performed. Samples of 40 to 45 specimens of each species were collected near Calvi (Corsica, France). Twenty-four enzyme loci were analysed, of which 17 appeared polymorphic. T. delaisi showed a high level of average observed heterozygosity (Ho ) of 0.140, as opposed to very low levels of 0.009 and 0.021 in T. tripteronotus and T. melanurus , respectively. Nei's genetic distance was 0.21 between T. delaisi and T. tripteronotus , 0.35 between T. delaisi and T. melanurus and 0.45 between T. tripteronotus and T. melanurus . We hypothesise that divergence of these species started before the Pleistocene and that the endemic species survived the Pleistocene glaciations in refugia within the Mediterranean. The possibility that T. tripteronotus and T. delaisi diverged through sympatric speciation is discussed. 相似文献
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Specimens of blue moki Latridopsis ciliaris (Forster in Bloch & Schneider, 1801) from New Zealand were shown to differ from specimens of copper moki Latridopsis forsteri (Castelnau, 1872) using two genetic methods—allozymes and muscle proteins. Allozyme techniques revealed fixed differences between blue and copper moki at 4 out of 15 loci. There was a genetic distance of 0.31–0.34 between population samples of the two colour morphs. The two morphs were also distinguished by iso‐electric focusing of muscle proteins. Meristic characters, counted in the specimens studied with genetic markers, revealed diagnostic markers in tubed lateral line scales and scales in the lower transverse series. It is concluded that specimens of blue moki from New Zealand and copper moki from New Zealand and Tasmania are valid species. 相似文献
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Penelope A. Luckens 《新西兰海洋与淡水研究杂志》2013,47(4):637-654
When grazing animals are excluded from any intertidal area algae grow unchecked. In screened frames on the shore where predation experiments are in progress such growth is undesirable. A number of shore herbivores were tested for their ability to remove such algal growth and prevent its reformation without interfering with the main experiments. Only the browsing species Lunella smaragda and Melagraphia aethiops were capable of removing large algal growths, and these species were acceptable food for some of the predatory species. The complex inter‐relationship between grazing species and shore zonation at several places near Auckland is discussed. 相似文献
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Previous genetic studies on perch (Perca fluviatilis L.) in northern and southern regions of Europe have shown low heterozygosity. No such investigation has been conducted in the central part of Europe. The genetic variability ofP. fluviatilis in four Swiss lakes (Lake Constance, Lake Zürich, Lake Geneva and Lake Maggiore) was investigated. These four lakes belong to three different drainage systems (Rhine, Rhone and Po) without connections. A total of 136 fish were analysed electrophoretically. Only one locus (SOD
*) was highly polymorphic in Lake Constance among the 27 loci studied. The expected heterozygosities for each population and for the total population were higher than in the previous studies but low (H
S= 0.38–2.7%;H
T=1.22%) and Nei's genetic distances were small (0.000–0.003). However, the jack-knifed mean of the Wright'sF
STwas calculated as 0.142, which indicates modest genetic differentiation among the perch populations in Switzerland, due to the differentiated population in Lake Constance. 相似文献
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应用聚丙烯酰胺凝胶电泳技术分析了孤雌生殖卤虫产生的罕见雄体、两性卤虫及其杂交后代 (F1)的酯酶 (EST)、超氧物歧化酶 (SOD)、过氧化物酶 (PRX)、碱性磷酸酶 (AL P)、四唑氧化酶(TO)和乳酸脱氢酶 (L DH)的同工酶酶谱表型。对编码 5种酶的 19个位点、35个等位基因的表达进行了遗传分析。结果表明 ,在 EST、PRX和 TO酶谱中既有共显性等位基因 ,又有沉默等位基因的表达 ;卤虫 PRX、AL P和 SOD为单体酶 ,在 EST和 TO酶谱中还存在着二聚体同工酶 ;除 LDH为单态外 ,其余 5种同工酶为多态酶。 相似文献
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