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2. Mate choice and reproductive success of two morphs of the seven spotted ladybird, Coccinella septempunctata (Coleoptera: Coccinellidae)
- Creator:
- Srivastava, Shefali and OMKAR
- Type:
- article, model:article, and TEXT
- Subject:
- Ladybird, Coccinella septempunctata, melanic, typical, mate choice, reproductive success, and age specific fecundity
- Language:
- English
- Description:
- Mate choice, reproductive success and fecundity of typical and melanic morphs of C. septempunctata were studied. Melanic as well as typical individuals preferred to mate with melanic males and females. Mate choice was mainly determined by females and to a lesser degree by males. Mating duration, oviposition period, and lifetime fecundity were highest (51.20 ± 2.82 min, 47.00 ± 2.79 days and 705.40 ± 69.85 eggs) when a melanic female mated with a melanic male and lowest (38.94 ± 1.68 min, 26.10 ± 2.54 days, 395.9 ± 36.25 eggs) when a typical female mated with a typical male. Longevity of both sexes of melanics was higher than of typicals. The fecundity function of both morphs was triangular but the daily oviposition was irregular. In melanic and typical females the peak oviposition (66.40 eggs/day and 48.30 eggs/day) occurred on the 23rd and 14th day of the oviposition period, respectively. Oviposition peaked earlier in typical females, but peak oviposition was higher and the oviposition period longer in melanic females. The higher reproductive success of melanics may favour this morph over typicals.
- Rights:
- http://creativecommons.org/publicdomain/mark/1.0/ and policy:public
3. Preference of female rats for the odours of non-parasitised males: the smell of good genes?
- Creator:
- Willis, Charlene and Poulin, Robert
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Hymenolepis diminuta, mate choice, urine, testosterone, and Y-maze
- Language:
- English
- Description:
- Many animals obtain reliable information about potential mates, including whether they are parasitised or not, mostly from olfactory cues in urine. Previous experiments with rodents have shown that females can detect parasites in males that arc potentially transmissible during copulation, so that females can directly avoid infection by discriminating against parasitised males. Here, using choice tests, we examine whether female rats can distinguish males infected with the tapeworm Hymenolepis diminuta Rudolphi, 1819, a parasite with a complex life cycle and thus not directly transmissible among rats. Female rats tended to spend more time investigating the urine of non-parasitised males than that of parasitised males. The magnitude of the parasite burden in the infected males had no effect on the females' preference for the non-parasitised males. We also found that parasitised males had lower testosterone levels in their blood than non-parasitised males, fliese results suggest that females use cues in male urine reflecting cither the presence of the parasite and/or lower testosterone levels to avoid parasitised males and possibly secure resistance genes for their offspring.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4. To mate or not to mate? Mate preference and fidelity in monogamous Ansell’s mole-rats, Fukomys anselli, Bathyergidae
- Creator:
- Bappert, Marie-Therese, Burda, Hynek, and Begall, Sabine
- Type:
- article, model:article, and TEXT
- Subject:
- monogamy, eusociality, extra-pair copulation, fidelity, mate choice, and African mole-rats
- Language:
- English
- Description:
- According to a hypothesis addressing the evolution of eusociality in mole-rats, the female (queen) is not able to raise her (first) offspring without a mate and thus to found a family. Therefore, we predict that the reproductive male (king) has to be socially faithful. In this study we tested this prediction and addressed the related question whether or not the presentation of a new female provokes enhanced sexual interest in male Ansell’s mole-rats (Fukomys anselli). We performed behavioral partner preference tests in Ansell’s mole-rats where two animals of choice were presented to a subject without allowing direct access. The kings spent significantly more time sniffing an unfamiliar queen or female than their own mate. If given the choice between an unfamiliar queen and her respective non-reproductive daughter, however, the tested kings significantly preferred the queen. In contrast, queens did not show a preference for either their own mate, an unrelated unfamiliar king, or a non-reproductive male. In a second experiment, we allowed the males to access the compartment of an unfamiliar female while their respective family stayed in an adjacent compartment. Only the non-reproductive adult males seized their chances to copulate with the unfamiliar female whereas the kings remained faithful. When reversing the test condition (i.e. females were given access to an unfamiliar male), aggressiveness of the males impeded sexual encounters in most cases. We recorded only three copulations, all of them between queens and non-reproductive males. We conclude that the reproductive status is crucial for reproductive decisions. Furthermore, the presence of family members influences the kings’ behavior. Since in Ansell’s mole-rats, repeated copulations over a longer period of cohabitation are necessary for ovulation and fertilization, the kings’ sexual fidelity could have been expected. We postulate that the maintenance of Ansell’s mole-rats’ families depends on the kings’ faithfulness.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public