Search results for "Zoology"

Putting Parasemia in its phylogenetic place: a molecular analysis of the subtribe Arctiina (Lepidoptera)

2016

Despite being popular among amateur and professional lepidopterologists and posing great opportunities for evolutionary research, the phylogenetic relationships of tiger moths (Erebidae: Arctiinae) are not well resolved. Here we provide the first phylogenetic hypothesis for the subtribe Arctiina with the basic aim of clarifying the phylogenetic position of the Wood Tiger Moth Parasemia plantaginis Hübner, a model species in evolutionary ecology. We sampled 89 species in 52 genera within Arctiina s.l., 11 species of Callimorphina and two outgroup species. We sequenced up to seven nuclear genes (CAD, GAPDH, IDH, MDH, Ef1𝛼, RpS5, Wingless) and one mitochondrial gene (COI) including the barcod…

Divergent parasite infections in sympatric cichlid species in Lake Victoria

2018

Parasitism has been proposed as a factor in host speciation, as an agent affecting coexistence of host species in species-rich communities and as a driver of post-speciation diversification. Young adaptive radiations of closely related host species of varying ecological and genomic differentiation provide interesting opportunities to explore interactions between patterns of parasitism, divergence and coexistence of sympatric host species. Here, we explored patterns in ectoparasitism in a community of 16 fully sympatric cichlid species at Makobe Island in Lake Victoria, a model system of vertebrate adaptive radiation. We asked whether host niche, host abundance or host genetic differentiatio…

No Evidence for Enforced Alloparental Care in a Cooperatively Breeding Parrot

2016

In cooperatively breeding species, in which non-breeding helpers assist in rearing the offspring of breeding individuals, conflicts of interest commonly occur between breeders and helpers over their respective contributions to offspring care. During such conflicts, breeders might use aggressive behavior to enforce contributions of helpers to offspring care, especially if helpers are not related to the breeders and their offspring and thus do not stand to gain indirect fitness benefits by helping. Using a combination of behavioral and genetic data, we investigated in the cooperatively breeding El Oro parakeet Pyrrhura orcesi (i) whether breeders are commonly dominant over helpers, (ii) wheth…

2021

Predator-induced plasticity in life-history and antipredator traits during the larval period has been extensively studied in organisms with complex life-histories. However, it is unclear whether different levels of predation could induce warning signals in aposematic organisms. Here, we investigated whether predator-simulated handling affects warning coloration and life-history traits in the aposematic wood tiger moth larva, Arctia plantaginis. As juveniles, a larger orange patch on an otherwise black body signifies a more efficient warning signal against predators but this comes at the costs of conspicuousness and thermoregulation. Given this, one would expect that an increase in predation…

Private information alone can trigger trapping of ant colonies in local feeding optima.

2015

Ant colonies are famous for using trail pheromones to make collective decisions. Trail pheromone systems are characterised by positive feedback, which results in rapid collective decision making. However, in an iconic experiment, ants were shown to become 'trapped' in exploiting a poor food source, if it was discovered earlier. This has conventionally been explained by the established pheromone trail becoming too strong for new trails to compete. However, many social insects have a well-developed memory, and private information often overrules conflicting social information. Thus, route memory could also explain this collective 'trapping' effect. Here, we disentangled the effects of social …

First extensive characterization of the venom gland from an egg parasitoid: structure, transcriptome and functional role.

2018

The venom gland is a ubiquitous organ in Hymenoptera. In insect parasitoids, the venom gland has been shown to have multiple functions including regulation of host immune response, host paralysis, host castration and developmental alteration. However, the role played by the venom gland has been mainly studied in parasitoids developing in larval or pupal hosts while little is known for parasitoids developing in insect eggs. We conducted the first extensive characterization of the venom of the endoparasitoid Ooencyrtus telenomicida (Vassiliev), a species that develops in eggs of the stink bug Nezara viridula (L.). In particular we investigated the structure of the venom apparatus, its functio…

Extended winters entail long-term costs for insect offspring reared in an overwinter burrow

2018

International audience; Winter imposes an ecological challenge to animals living in colder climates, especially if these adverse conditions coincide with reproduction and offspring rearing. To overcome this challenge, some insects burrow in the soil to protect adults, larvae, or eggs from negative effects of winter. However, whether this protection is effective against any long-term consequences of changes in winter duration is unclear. Here, we investigated the long-term effects of winter length variation on eggs of the European earwig Forficula auricularia. In this insect, females construct and maintain a burrow between late autumn and spring, in which they provide extensive forms of care…

Evolution of the Dentition in Holocephalans (Chondrichthyes) Through Tissue Disparity

2020

Abstract The Holocephali is a major group of chondrichthyan fishes, the sister taxon to the sharks and rays (Elasmobranchii). However, the dentition of extant holocephalans is very different from that of the elasmobranchs, lacking individual tooth renewal, but comprising dental plates made entirely of self-renewing dentine. This renewal of all tissues occurs at the postero-lingual plate surface, as a function of their statodont condition. The fossil record of the holocephalans illuminates multiple different trends in the dentition, including shark-like teeth through to those with dentitions completely lacking individual teeth. Different taxa illustrate developmental retention of teeth but w…

Invasive parasites are detectable by their abundance-occupancy relationships: the case of helminths from Liza haematocheilus (Teleostei: Mugilidae)

2018

Abstract The biogeographic patterns of abundance and prevalence of helminths from Liza haematocheilus were studied across its native (Sea of Japan) and introduced (Sea of Azov) distribution ranges. Abundance-occupancy relationships (AORs) were tested for the core-satellite and enemy release (ERH) species hypotheses in eight and 14 host samples from the native and introduced host ranges, respectively. The AOR model fitted parasite data extremely well, irrespective of whether the host or the parasite species were native or invasive. Except for co-introduced monogeneans, species were less abundant and prevalent in the introduced host population than in the native one, which agrees well with th…

Love at first sniff: a spermatophore-associated pheromone mediates partner attraction in a collembolan species

2017

Mate choice is essential in most animals, as a good choice of mating partner largely determines reproductive success. Much evidence shows that olfactory cues play an important role in mate choice. However, the integration of chemical, visual and acoustic cues, often used when both partners meet, makes it hard to test whether olfaction alone can mediate reproductive decisions. Interestingly, several invertebrates have adopted a mating system where males deposit their sperm (packed in spermatophores) in the environment for females to pick up with no visual contact between the sexes. In this case the male cue is conveyed by the spermatophore only. Earlier studies on a species with indirect spe…