BackgroundAs currently defined, the genus Postandrilus Qui and Bouché, 1998, (Lumbricidae) includes six earthworm species, five occurring in Majorca (Baleares Islands, western Mediterranean) and another in Galicia (NW Spain). This disjunct and restricted distribution raises some interesting phylogeographic questions: (1) Is Postandrilus distribution the result of the separation of the Baleares-Kabylies (BK) microplate from the proto-Iberian Peninsula in the Late Oligocene (30–28 Mya) – vicariant hypothesis? (2) Did Postandrilus diversify in Spain and then colonize the Baleares during the Messinian salinity crisis (MSC) 5.96–5.33 Mya – dispersal hypothesis? (3) Is the distribution the result of a two-step process – vicariance with subsequent dispersal?Methodology/Principal FindingsTo answer these questions and assess Postandrilus evolutionary relationships and systematics, we collected all of the six Postandrilus species (46 specimens – 16 locations) and used Aporrectodea morenoe and three Prosellodrilus and two Cataladrilus species as the outgroup. Regions of the nuclear 28S rDNA and mitochondrial 16S rDNA, 12S rDNA, ND1, COII and tRNA genes (4,666 bp) were sequenced and analyzed using maximum likelihood and Bayesian methods of phylogenetic and divergence time estimation. The resulting trees revealed six new Postandrilus species in Majorca that clustered with the other five species already described. This Majorcan clade was sister to an Iberian clade including A. morenoe (outgroup) and Postandrilus bertae. Our phylogeny and divergence time estimates indicated that the split between the Iberian and Majorcan Postandrilus clades took place 30.1 Mya, in concordance with the break of the BK microplate from the proto-Iberian Peninsula, and that the present Majorcan clade diversified 5.7 Mya, during the MSC.Conclusions Postandrilus is highly diverse including multiple cryptic species in Majorca. The genus is not monophyletic and invalid as currently defined. Postandrilus is of vicariant origin and its radiation began in the Late Oligocene.

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Phylogenetic analysis has revealed many potential new earthworm species and has led to changes in current taxonomic classifications. Here, we propose the addition of two new earthworm genera, Galiciandrilus gen. nov. and Compostelandrilus gen. nov., to the family Lumbricidae based on morphological evidence and phylogenetic analysis of nuclear 28S rRNA and mitochondrial 16S rRNA, 12S rRNA, ND1, COII and tRNA gene regions (4680 bp). Galiciandrilus gen. nov. comprises the species originally described as Cernosvitovia bertae and Allolobophora morenoe (later renamed Postandrilus bertae and Aporrectodea morenoe, respectively). Compostelandrilus gen. nov. includes two new earthworm species, Compostelandrilus bercianus sp. nov. and Compostelandrilus menciae sp. nov., which are restricted to a small area of northwestern Spain. Divergence times (14.9-26.5 Mya) and branch lengths (0.7-1.45) in the species included in the Iberian clade are higher than those usually observed in most lumbricid monophyletic genera. The monophyly of these two phylogenetically distinct earthworm genera is not corroborated by any of the external or internal morphological synapomorphies commonly used in earthworm alpha taxonomy. This confirms the anatomical plasticity of the group and the need for extensive revision of the Lumbricidae taxonomy. Given the restricted geographical distribution of the earthworm species under study (< 50 km 2) and their basal phylogenetic position in the Lumbricidae tree, future conservation efforts should be initiated to preserve this unique biological diversity.

In simultaneous hermaphrodites with reciprocal mating, multiple mating may be a male strategy that conflicts with female interests, and therefore an intra‐individual sexual conflict regarding the number of matings may be expected. The evolutionary outcome of this sexual conflict will depend on the costs and benefits that extra mating entails for each sexual function. In the present study, we investigated the costs and benefits of multiple mating on cocoon number, cocoon mass, and cocoon hatching success in the redworm Eisenia andrei, a simultaneous hermaphrodite with reciprocal insemination, by manipulating the number of matings with different partners. We did not detect any reduction in the female reproductive output (number and mass of cocoons) with increasing number of mating partners. However, we found that multiple mating showed benefits for female reproduction that increased the hatching success of the cocoons. This effect may be a result of increased quantity and/or diversity of sperm in the spermathecae of multiple mated earthworms. Further studies are required to clarify the mechanism underlying the increased cocoon hatching success when redworms engage in multiple matings. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ••, ••–••.