Biology subjects

Niida, T.

Publications and source records attributed to Niida, T..

4 recordsLinked to original sources

bioRxiv2025

Synchronous Hatching of 2-Day Delayed Intruders in Reproductive Competition in the Burying Beetle

Appropriate hatching time is important for successful brood parasitism in some bird and insect groups. Parental burying beetles typically rear their larvae on carcasses buried in nests; however, they occasionally raise brood-parasitic larvae from eggs dumped by other females. Parasitic larvae must hatch synchronously with host larvae because the host parents indiscriminately accept any larvae during that period. However, parasites in burying beetles are assumed to have more severe restrictions on synchronous hatching than those in birds because of less predictability of reproductive sites, the necessity for ovarian development at the site, and difficulty in adjusting by oviposition. Is the hatching of parasitic larvae synchronized with that of host larvae, even if the reproductive behavior of the parasites lags behind that of the host owing to restrictions? In the burying beetle Nicrophorus quadripunctatus Kraatz, we observed the hatching of host and parasite offspring under experimental conditions in which female parasites (intruders) encountered carcasses that had been secured by female hosts (residents) two days earlier. In 14 of the 40 replicates, defeated intruders dumped eggs, residents laid 36 eggs, and intruders laid six eggs on average. The hatching of intruder offspring was synchronized with that of the resident offspring despite the two-day lag. Egg dumping is regarded as brood parasitism. Notably, the period from contact with carcasses to hatching was significantly shorter for intruders than for residents. Advances in hatching time may contribute to the success of brood parasitism.

animal behavior and cognition↗

bioRxiv2023

Photoreceptor genes in a trechine beetle, Trechiama kuznetsovi, living in the upper hypogean zone

To address how organisms adapt to a new environment, subterranean organisms whose ancestors colonized subterranean habitats from surface habitats have been studied. Photoreception abilities have been shown to have degenerated in organisms living in caves and calcrete aquifers. Meanwhile, the organisms living in a shallow subterranean environment, which are inferred to reflect an intermediate stage in an evolutionary pathway to colonization of a deeper subterranean environment, have not been studied well. In the present study, we examined the photoreception ability in a trechine beetle, Trechiama kuznetsovi, which inhabits the upper hypogean zone and has a vestigial compound eye. By de novo assembly of genome and transcript sequences, we were able to identify photoreceptor genes and phototransduction genes. Specifically, we focused on opsin genes, where one long wavelength opsin gene and one ultraviolet opsin gene were identified. The encoded amino acid sequences had neither a premature stop codon nor a frameshift mutation, and appeared to be subject to purifying selection. Subsequently, we examined the internal structure of the compound eye and nerve tissue in the adult head, and found potential photoreceptor cells in the compound eye and nerve bundle connected to the brain. The present findings suggest that T. kuznetsovi has retained the ability of photoreception. This species represents a transitional stage of vision, in which the compound eye regresses, but it may retains the ability of photoreception using the vestigial eye.

zoology↗

bioRxiv2023

The detection of brood parasitism and quasi-parasitism in the burying beetle Nicrophorus quadripunctatus under natural conditions

Intraspecific brood parasitism (IBP), where a parasitic female lays eggs in the nest of another female of the same species, occurs in insects and birds. Also, quasi-parasitism (QP), where a parasitic female copulates with a host male at his nest and lays eggs that are fertilized by the male, has been documented in a few monogamous birds, but QP has not been observed in any insects. Burying beetles, genus Nicrophorus, use small vertebrate carcasses for reproducing and providing biparental care for their offspring. IBP has been observed in one burying beetle by laboratory experiments, but has not been well reported under natural conditions. IBP and QP may occur under natural conditions in burying beetles. Here we focused on a burying beetle, Nicrophorus quadripunctatus. Ten broods, consisting of larvae and their parental female and male, were collected from a deciduous forest. To investigate the kin relationship between parents and larvae, eight microsatellite DNA loci were used. We detected three types of parasitic larvae: 1) larva not related to either its parental female or male, 2) larva not related to its parental female, but unknown regarding its parental male, and 3) larva not related to its parental female, but related to its parental male. These results suggested that IBP and QP can occur with certain frequencies in the reproduction of N. quadripunctatus under natural conditions. QP is thought to have a benefit for a parental male to enhance his paternity within one brood in this species.

animal behavior and cognition↗

bioRxiv2020

Sexually monomorphic wing pigmentation pattern does not contribute to mate choice in Drosophila guttifera

In many animal groups, sexually dimorphic ornaments are thought to be evolved by intraspecific competition or mate choice. Some researchers pointed out that sexually monomorphic ornaments could also be evolved by mate choice by both sexes or either sex. Many species of fruit fly have sexually monomorphic wing pigmentation. However, involvement of their sexually monomorphic ornaments in mate choice has not been tested. We aimed to examine whether the sexually monomorphic polka-dotted pattern on wings of Drosophila guttifera contributes to mate choice. Because D. guttifera does not mate in the dark condition at all and courtship sound was not observed, some visual information is likely to be used in mating behaviour. We compared the number of mates between individuals with and without wings, and found that presence of wings influenced mate choice in both sexes. We then compared the number of mates between individuals bearing replaced wings, one group for conspecific D. guttifera wings and another group for heterospecific D. melanogaster wings with no pigmentation pattern. The effect of conspecific/heterospecific wings was only detected in mate choice by females. By comparison between wild-type and black-painted wings, we found no evidence of contribution of wing pigmentation pattern to mate choice in either sex.

animal behavior and cognition↗