ISOLATING MECHANISMS AND MODALITIES OF SPECIATION IN THE JAERA ALBIFRONS SPECIES COMPLEX (CRUSTACEA, ISOPODA)

• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.547.539; http://decapoda.nhm.org/pdfs/22748/22748.pdf

Solignac, M. (Laboratoire de Biologie et Genetique Evolutives, C.N.R.S., 91190 Gif-sur-Yvette, France) 1981. Isolating mechanisms and modalities of speciation in the Jaera albifrons species complex (Crustacea, Isopoda). Syst. Zool., 30:387-405.—Jaera albifrons is a complex of five intertidal species of Crustacea that are abundant on the cold and temperate coasts of the North Atlantic. Two or three species of Jaera albifrons occur frequently on the same strand, partially isolated (approximately 50%) by ecological preferences. In zones of species overlap, hybrids remain scarce (0.6 % average); sexual isolation is due to homogamic tenden-cies of male sexual choice, to specific male displays and especially to female reactivity. Most of the F2 recombinations are inviable; hybrid fitness, estimated from demographic data, is about 0.15. Other isolating mechanisms (e.g. temporal, mechanical and gametic isolation) are missing. The study of variability of isolating mechanisms between pairs of species and pop-ulations and of incipient isolation within species allows formulating a plausible hypothesis on their origins. A geographical mode of speciation with establishment of sexual isolation and hybrid breakdown during geographic isolation is likely. [Modes of speciation; isolating mech-