In many animals in which females store sperm, males may detect female mating status and, in order to outcompete rival sperm, increase ejaculate size when copulating with non-virgin females. Although most studies have been restricted to organisms with separate sexes, theoretical models suggest that sperm competition should also be an important selective agent shaping life-history traits in simultaneous hermaphrodites. Nevertheless, the empirical support for ejaculate adjustment in a mating opportunity is scarce in hermaphrodites. In the present study, we performed a double-mating experiment to determine whether earthworms (Eisenia andrei ) detect the mating status of their partners and whether they respond by adjusting their ejaculate. We found that earthworms triplicated the donated sperm when mating with a non-virgin mate. Moreover, such increases were greater when the worms were mated with larger (more fecund) partners, indicating that earthworms perform a fine-tune control of ejaculate volume. The results of the present study suggest that, under high intensity of sperm competition, partner evaluation is subject to intense selection in hermaphrodite animals, and donors are selective about to whom they donate how much sperm.
The Iberian hare (Lepus granatensis Rosenhauer, 1856) has the western distribution limit in the south of the dorsal galega. This work provides new data on the status of the species over 16 years of sampling. Indices of relative abundance of Iberian hare were determined in the dorsal galega through night censuses carried out in each season. During the years 2006-2020, a total of 2,500 km was gone down along forest tracks in the Suido and Faro de Avión mountain ranges, spread over 196 days. The relative abundance for the hare ranged between 0.07 and 0.30 ind/km for the Faro de Avión with an average of 0.18 ± 0.06 ind/km, and between 0.02 and 0.22 ind/km for the Suido, with an average of 0.07 ± 0.06 ind/km. The monitoring along the years of the studied population supports scientific decision-making for conservation and hunting management purposes.
Dytiscids prey on a variety of items including other invertebrates but also larger prey such as frogs and fish. However, there have been no reports concerning predation on caudata adults by larvae of dytiscids. In this paper, we describe a predation event by a larva of diving beetles of the species Dytiscus marginalis Linnaeus, 1758 on an adult Iberian newt Lissotriton boscai (Lataste, 1879). This report represents the first observation of hunting behavior of larvae of diving beetles preying on a living post-metamorphic newt.
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