Semen promotes oocyte development in Sebastesschlegelii elucidating ovarian development dynamics in live-bearing fish.

In some vertebrates and invertebrates, semen release factors affecting female physiology and behavior. Here, we report that semen delivered to females is potentially beneficial for promoting oocyte development in a viviparous teleost, Sebastes schlegelii. 88% of mated ovaries develop normally and give birth to larval fish, whereas 61% of non-mated ovaries are arrested in the previtellogenic stage. Semen's significant role (p < 0.0001) in promoting oocyte development may involve remodeling follicular cells and regulating the expression of the extracellular matrix, which facilitates cell communication. Furthermore, the ovarian response to semen may influence the brain, affecting hormone release, follicular cell development and steroid production, and crucial for oocyte growth. This mechanism, which could potentially delay maternal investment in offspring until male genetic input occurs to avoid energy wastage, has not been previously described in teleosts. These findings enhance our understanding of ovarian development in viviparous fish, with broader implications for reproductive biology.

Spider webs capture environmental DNA from terrestrial vertebrates.

Environmental DNA holds significant promise as a non-invasive tool for tracking terrestrial biodiversity. However, in non-homogenous terrestrial environments, the continual exploration of new substrates is crucial. Here we test the hypothesis that spider webs can act as passive biofilters, capturing eDNA from vertebrates present in the local environment. Using a metabarcoding approach, we detected vertebrate eDNA from all analyzed spider webs (N = 49). Spider webs obtained from an Australian woodland locality yielded vertebrate eDNA from 32 different species, including native mammals and birds. In contrast, webs from Perth Zoo, less than 50 km away, yielded eDNA from 61 different vertebrates and produced a highly distinct species composition, largely reflecting exotic species hosted in the zoo. We show that higher animal biomass and proximity to animal enclosures increased eDNA detection probability in the zoo. Our results indicate a tremendous potential for using spider webs as a cost-effective means to monitor terrestrial vertebrates.

Lethal combats in the forest among wild western gorillas.

Lethal intergroup encounters occur in many species because of sexual selection. While documented in mountain gorillas, they are absent in western gorillas as, instead, it is predicted by their higher feeding (frugivory) and mate competition (single-vs. multi-male groups). We investigate whether the injuries on three dead silverbacks and one adult female from four groups of western gorillas in the Central African Republic, resulted from interactions with gorillas or leopards. We identified two distinct injury patterns caused by gorillas (isolated lacerations, round wounds) and leopards (punctures clustered on head/neck) by analyzing injuries caused by mountain gorillas and leopards to gorillas and non-gorilla species, respectively. The western gorilla injury pattern is similar to that of mountain gorillas suggesting that lethal encounters occur, albeit infrequently, as predicted by sexual selection in a one-male society. While sexual dimorphism and polygynous sociality favored the evolution of violent encounters, multiple males in groups may influence their frequency.

A pulse check for trends in sea turtle numbers across the globe.

Population declines of vertebrates are common, but rebuilding marine life may be possible. We assessed trends in sea turtle numbers globally, building 61 time series of abundance extending beyond 2015, representing monitoring in >1200 years. Increases were widespread with significant upward trends, no significant change, and significant downward trends in 28, 28, and 5 time series, respectively. For example, annual nest numbers increased between 1980 and 2018 from around 4,000 to 16,000 for green turtles at Aldabra (Seychelles, Indian Ocean) and between 2008 and 2020 from around 500 to 35,000 for loggerhead turtles in Sal (Cape Verde, north Atlantic). However, conservation concerns remain. Major populations may experience declines, such as loggerhead turtles in Oman, while previous upward trends can be reversed, as with green turtles nesting at Tortuguero (Costa Rica, Caribbean). Further, decreases in abundance were evident in several leatherback turtle time series. These concerns show there is no room for complacency for sea turtle conservation.

Doppler detection triggers instantaneous escape behavior in scanning bats.

Animals must instantaneously escape from predators for survival, which requires quick detection of approaching threats. Although the neural mechanisms underlying the perception of looming objects have been extensively studied in the visual system, little is known about their auditory counterparts. Echolocating bats use their auditory senses to perceive not only the soundscape, but also the physical environment through active sensing. Although object movement induces both echo delay changes and Doppler shifts, the actual information required to perceive movement has been unclear. Herein, we addressed this question by playing back phantom echoes mimicking an approaching target to horseshoe bats and found that they relied only on Doppler shifts. This suggests that the bats do not perceive object motion in the spatiotemporal dimension (i.e., positional variation), as in vision, but rather take advantage of acoustic sensing by directly detecting velocity, thereby enabling them to respond instantaneously to approaching threats.

Proteome-metabolome profiling of wax gland complex reveals functional changes in honeybee, Apis mellifera L.

Wax gland complex (WGC) serves as the primary generator of beeswax; however, the dynamic biological function in wax secretion remains unclear. To elucidate the developmental mechanism of WGC, we conducted a comprehensive analysis to reveal the variations in proteins and metabolites among the newly emerged bee (NEB), wax-secreting bee (WSB), and overaged bee (OAB). We identified 3,295 proteins and 159 metabolites in WGC. Specifically, NEB elevated the expression of ribosomal proteins for preparing the glandular organ. While WSB promoted the size of epidermal cells and oenocytes, the enrichment of fatty acids and energy metabolism in WSB suggested a strong ability in wax synthesis. In OAB, disorganized wax tubules, and up-regulated cysteine proteases reflected the gland degeneration. These findings highlight the dynamic changes in the level of molecule and morphological structure in WGC, offering valuable insights into the development and mechanism of wax secretion in honeybees and other wax insects.

Behavioral, physiological, and genetic drivers of coping in a non-human primate.

Animals experience stressful situations, from predation to social conflicts, but mostly deal with them successfully. This adaptive mechanism, coping, reduces the adverse effects of stressors, and its failure may result in reduced fitness. Substantial inter-individual variation in coping is observed, yet little is known about how behavioral, physiological and genetic drivers regulate coping holistically and contribute to such variations. We assessed behavioral coping styles (n=30), emotional arousal (n=12), and personalities (n=32) of long-tailed macaques (Macaca fascicularis) and also investigated the association of coping with a valine/methionine polymorphism encoded by a critical human stress regulatory gene, catechol-O-methyltransferase (COMT) (n=26). Personality and the human equivalent COMT Val/Met polymorphism were associated with "nonaggression-based" and "aggression-based" coping styles. Compared to nonaggression-based, aggression-based copers maintained higher average facial temperatures, indicating potentially lower emotional arousal, as measured using infrared thermography. These findings demonstrate a complex interplay of various proximate mechanisms governing coping in a non-human primate.