Sex identification and sex-specific behaviour are fundamental to fish reproductive ecology, yet their spatial variation along environmental gradients remains insufficiently understood. Adult brown trout (Salmo trutta) were sampled during the spawning period at 43 stream sites, each with at least three adult trout. We investigated sex ratios and morphometric characteristics (length, weight, and relative head length) of brown trout in relation to altitude, Strahler stream order, stream depth range, and mean stream depth across the Bohemian Forest (Central Europe). In total, 311 individuals were sexed. Males were significantly larger and had relatively longer heads than females. The proportion of males increased significantly with altitude, indicating a male-biased sex ratio in higher-elevation streams. Fish weight decreased with altitude along upstream-downstream gradients, suggesting that environmental conditions at higher elevations may constrain growth and body size. Measured temperature, Strahler stream order, and depth range had no detectable effect on brown trout sex ratios and morphometric characteristics. These results indicate sex-specific spatial segregation during the spawning period, likely driven by differences in migratory behaviour, competition, and energetic constraints, highlighting the role of natural environmental gradients in shaping salmonid population structure.
In the sand goby, Pomatoschistus minutus, males build nests and provide sole care for the eggs until hatching. We examined whether male and female courtship before spawning were associated with subsequent filial cannibalism by the male. Full and partial brood cannibalism showed distinct patterns. Broods that were later completely cannibalised were smaller, and spawning occurred later than in broods of males that received continued care. In contrast, brood size was not correlated with the extent of partial brood cannibalism. Instead, female courtship was negatively associated with partial brood cannibalism, whereas no similar relationship was found for male courtship. These results are consistent with full and partial brood cannibalism reflecting different biological mechanisms. Female courtship may provide information about future male care, influence subsequent male behaviour, or covary with brood or egg quality.
Ophidiomyces ophidiicola (Oo) is a snake fungal pathogen that causes ophidiomycosis. The disease manifests as dermatomycosis and/or systemic mycosis, and can be fatal. It occurs in free-ranging snakes in Asia, Europe and the USA and has also been demonstrated in captive snakes. We tested for the presence of Oo in free-ranging snake populations in the Czech and Slovak Republics (n = 420) between 2019 and 2022, focusing mainly on grass snakes (Natrix natrix) and dice snakes (Natrix tessellata), as well as various captive exotic species (n = 207). After collecting skin swabs, we tested for Oo using the qPCR method. We confirmed fragmented occurrence of Oo in the Czech Republic (total prevalence 15%) and recorded Oo in the Slovak Republic for the first time (total prevalence 33.9%). The highest prevalence was observed in N. tessellata (20.2%), which appears to be the most susceptible species. The pathogen was not detected in captive snakes.
A cryptic loach species of the genus Misgurnus (Cypriniformes: Cobitidae) has been reported as Misgurnus sp. Type I sensu Okada et al. (2017) (hereafter called Type I loach) from the Japanese Archipelago, in addition to the common nominal species, M. anguillicaudatus (hereafter called Type II loach). Although both species co-exist in the Naka-ikemi Wetland, Fukui Prefecture, their mechanism of reproductive isolation is unknown. Differences in sexual dimorphism might reflect differences in reproductive behaviour that contribute to reproductive isolation between the two species. We investigated the morphological characteristics of the two loach species at two sympatric sites and observed several morphological differences. Type I differ from Type II loaches in the following morphological traits and sexual dimorphisms: in males, generally less developed lamina circularis, shorter anal fins, and lack of a pair of raised ridges in the anterior portion of the body side; in females, lack of spawning scars on the body side. These morphological differences between the two sympatric loaches may reflect differences in their spawning behaviour. Furthermore, it may represent one of the factors responsible for reproductive isolation between the two species.
Spermatozoa are the most variable cells across animal taxa. Phylogeny, speciation and postcopulatory sexual selection are typical factors that explain the sperm morphology variation in animals, and now these differences can also be explored on the level of genomic and proteomic differentiation. However, in non-model organisms, it is often difficult to employ these techniques because genomes are not yet available for most animal species, particularly for free-living songbirds (Passeriformes). Here, we employed label-free proteomics to generate proteomes in the zebra finch, a songbird species with an annotated genome and five wild-living songbirds representing five families within the Passerida clade, all with poorly known genomes. The results show that protein mapping of the new passerine proteomes to the zebra finch genome was successful, thus yielding highly similar protein identifications and a sufficient number of unique peptides in all the studied proteomes. Interestingly, while passerine sperm proteomes only partially reflect phylogenetic relationships between passerine families, midpiece length correlates with at least 59 proteins enriched in mitochondrial metabolism. Similar sperm proteomes seem to have evolved convergently across passerine lineages, potentially due to varying levels of sperm competition and marked variation in sperm sizes.
Abstract. This review updates the information on the actual status and distribution of freshwater gobies in Bosnia and Herzegovina. The available literature has been critically reviewed to provide more complete and up-to-date information. Consequently four species are proposed for removal from the national checklist, given the lack of any data to support their presence: Knipowitschia panizzae, Pomatoschistus microps, Proterorhinus marmoratus and Zosterisessor ophiocephalus. Therefore, the freshwater gobiid fauna is confirmed to include seven species from six genera. The Adriatic Sea basin (Neretva River catchment) is inhabited by three endemic species: Knipowitschia radovici, Orsinigobius croaticus and Ninnigobius canestrinii, while the Black Sea basin (Danube River catchment) is inhabited by the invasive species: Babka gymnotrachelus, Neogobius fluviatilis, Neogobius melanostomus and Ponticola kessleri. However, due to the possibility of misidentify the finding of B. gymnotrachelus is questionable and needs confirmation. Distribution of both endemic Knipowitschia and Orsinogobius species is restricted to small areas in the lower Neretva River catchment on both sides of the Croatia-Bosnia and Herzegovina border. The vulnerability of these species is discussed, and the IUCN conservation and units meriting conservation attention were identified. The invasive character of other species is highlighted. This review indicates that the knowledge on the Bosnia-Herzegovinian freshwater gobiid fauna is still far from complete, hence this up-to-date checklist can serve as a basis for further ecological and zoogeographical studies. For better species inventory, finer scale distribution surveys are needed, followed by detailed morphological, molecular phylogenetic and ecological studies.
A study on the effects of prescribed burning on rodent community ecology was conducted in Serengeti National Park, Tanzania. The study aimed at generating ecological knowledge about the changes in rodent communities when areas of the park are intentionally burned to regulate grasslands or reduce undergrowth that can lead to uncontrolled forest fires. A completely randomized design (CRD) factorial layout with two treatments (burned and unburned) and two replications was applied. A total of 148 animals comprising six species of rodent and one insectivore were captured over 2,940 trap nights. Among the trapped individuals, 41.9% were adults, 16.1% juveniles and 41.9% sub-adults. Males and females were at parity between treatments. Species abundance was estimated using the minimum number alive (MNA) method for different rodent species and was found to vary with treatment where Mastomys natalensis declined in burned plots whilst Arvicanthis niloticus increased. However, species diversity did not differ across treatments (F-1,F-10 = 0.15, p = 0.70). Differences in the reproductive condition of female M. natalensis (z = 4.408, df = 15, p < 0.001) and A. niloticus (z = 2.381, df = 15, p = 0.017) were observed between treatments showing that higher numbers of reproductively active females were observed in burned plots in March, whilst in unburned plots more were observed from November to February. Conservation strategies involving periodic habitat burning should, therefore, consider small mammal reproductive periods to ensure that species potentially at risk are not adversely affected and able to rapidly recover from the effects of burning in temporarily lowering food resources and longer term impacts of increased predation caused by reduced cover.
The global environment is faced with growing threats from anthropogenic disturbance, propelling the Earth into a 6th mass extinction. For the world's mammals, this is reflected in the fact that 25% of species are threatened with some risk of extinction. During this time of species loss and environmental alteration, the world's natural history museums (NHMs) are uniquely poised to provide novel insight into many aspects of conservation. This review seeks to provide evidence of the importance of NHMs to mammal conservation, how arguments against continued collecting of physical voucher specimens is counterproductive to these efforts, and to identify additional threats to collecting with a particular focus on small mammals across Africa. NHMs contribute unique data for assessing mammal species conservation status through the International Union for Conservation of Nature's (IUCN) Red List of Threatened species. However, NHMs' contributions to mammal conservation go well beyond supporting the IUCN Red List, with studies addressing topics such as human impacts, climate change, genetic diversity, disease, physiology, and biodiversity education. Increasing and diverse challenges, both domestic and international, highlight the growing threats facing NHMs, especially in regards to the issue of lethally sampling individuals for the purpose of creating voucher specimens. Such arguments are counterproductive to conservation efforts and tend to reflect the moral opposition of individual researchers than a true threat to conservation. The need for continued collecting of holistic specimens of all taxa across space and time could not be more urgent, especially for underexplored biodiversity hotspots facing extreme threats such as the Afrotropics.
Hosts of obligate avian brood parasites can reduce the costs of raising parasitic offspring by rejecting foreign eggs from their nests. Rejecter hosts use various visual and tactile cues to discriminate between own and foreign eggs. The blunt pole hypothesis specifically states that avian-perceivable visual information at and around the broader pole of the eggshell contains more salient recognition cues than does the sharp pole of the same egg. The directional prediction is, therefore, that eggs painted non-mimetically on their blunt pole should more likely be rejected relative to those similarly painted on their sharp pole. This hypothesis had been experimentally tested and its predictions supported solely in mimetic avian host-parasite systems, with hosts producing denser and more variable eggshell maculation patterns at the blunt pole, and in one species with immaculate eggs but still with distinctly discernible blunt-pole specific colouration. Here we aimed to expand upon these previous works and assessed whether the blunt pole of model eggs contains more salient egg rejection cues, relative to the sharp pole, for the American robin (Turdus migratorius), a robust rejecter of non-mimetic brown-headed cowbird (Molothrus ater) eggs. In this system host eggs are uniformly immaculate whereas the brood parasitic shell is maculated. We painted model cowbird-sized eggs on either the blunt or the sharp half to mimic the immaculate robin egg colours and the other half to resemble non-mimetic egg colours and patterns. There was no statistical support for the predicted outcomes of the blunt pole hypothesis in our trials as rejection rates were similar regardless of whether eggs were painted with non-mimetic colours on the blunt or sharp poles. Future work should test the role of asymmetrical signalling content for anti-parasitic rejection of eggs in additional host species, especially those with both immaculate own and mimetic parasitic eggs.
Rails (family Rallidae) are adapted to wetland habitats, nesting in emergent vegetation where flooding is one of the main factors that contributes to nesting failure rates. We conducted an experiment to test the capacity of water rail and Japanese quail embryos to survive flooding. During the experiment, 52 water rail and 60 quail eggs were divided into three groups. One control group was artificially incubated in standard conditions and the other two groups were submerged during artificial incubation for 2 hours and 3 hours, respectively, in the third week of the incubation period in water at 21 degrees C. A total of 88.2% of water rail eggs hatched in the control group, 83.3% in the 2 h flooded group and 29.4% in the 3 h flooded group. For the quail eggs, 75% hatched in the control group, 10% in the 2 h flooded group and 5% in the 3 h flooded group. Water rail embryos were five times more resistant to 2 h flooding conditions, and approximately twice as resistant to a 3 h immersion compared to quail embryos. The elevated survival rate of water rail embryos may be related to their capacity to enter torpor.
Although rapid growth in the extent of urbanized habitats across the globe represents a major threat to biodiversity, there is growing evidence that urban ecosystems can represent suitable habitats for many taxa, including birds. Exploring aspects of bird ecology across the urban-rural gradient, including determinants of habitat associations, are crucial to understanding responses to urbanisation. Here, we examined factors affecting nest-site selection of Eurasian magpies across an urban-rural gradient, contrasting urban and non-urban habitats. The presence and density of Eurasian magpie nests was positively associated with the proportion of green urban areas, and negatively with forests, arable land and buildings, despite habitat associations differing across the urban-rural gradient. We also found a negative relationship between nest height and distance from city edge. The highest nests were found in city centre residential areas, whereas the lowest nests were in the new residential areas. We conclude that Eurasian magpies can successfully exploit urban environments, partially due to adaptation of their nesting behaviour. In particular, they construct their nests higher in urban areas to avoid the negative impacts of human disturbance and predation.
This study investigated the browning plasticity of white adipose tissue (WAT) in Tupaia belangeri during cold acclimation and rewarming in order to demonstrate the adaptation mechanism of tree shrews to environmental change. The experimental group was transferred to a cold temperature, 5 +/- 1 degrees C, acclimated for 28 d, and then returned to 25 +/- 1 degrees C for 28 d, while the control group was maintained at the acclimation temperature, 25 +/- 1 degrees C, for 56 d. Body mass, food intake, resting metabolic rate (RMR), WAT mass, morphology and related gene expression in male T. belangeri were measured. The results showed that body mass, food intake and RMR increased significantly under cold acclimation. There was also a significant increase in WAT mass and expression of peroxisome proliferation receptor alpha (PPAR alpha), peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1 alpha), cyclooxygenaseII (COXII), bone morphogenetic protein 7 (BMP7) and the PR domain containing 16 (PRDM16), all of which decreased to control levels after rewarming. Further, WAT cells showed more multilocule adipocytes during cold acclimation, which returned to control levels after rewarming. These results suggest that browning may appear in the WAT of T. belangeri during cold acclimation. The return to control levels of WAT cell characteristics and expression of the genes involved in WAT browning after rewarming demonstrates strong browning plasticity.
The common cuckoo Cuculus canorus is an obligate brood parasite that lays its eggs in the nests of small passerines. It has long been hypothesized that cuckoo eggs should be structurally stronger than host eggs or those of non-parasitic cuckoos to reduce chances of breakage during laying, to prevent accidental damage during incubation and/or to hinder their rejection through puncture ejection by the host. Therefore, we analysed selected characteristics of a sample of freshly laid eggs of the common cuckoo with two of its major hosts, the reed warbler Acrocephalus scirpaceus and great reed warbler Acrocephalus arundinaceus, and a sample of species with known puncture resistant eggs. We found that in puncture resistance tests cuckoo eggs tolerated on average 231 g. The cuckoo eggs were 3.3 and 2.5 times stronger than those of the reed warbler and great reed warbler, respectively. Greater shell thickness can explain only 17% of the total extra strength of the cuckoo eggs (125.97 g). When we controlled for the confounding effects of egg size (using a sample of eggs of normal strength from bird species of varying size), the common cuckoo eggs were 2.2 times stronger than expected for their size. Our results are consistent with the hypothesis that cuckoo eggs are structurally stronger and this trait probably represents an adaptation for a brood parasitic life style.
We describe two new species of white-toothed shrews from south-western and central Ethiopia, based on recent collections and an application of morphological and genetic methods, Crocidura similiturba sp. nov. and Crocidura makeda sp. nov. Comparisons are provided with other Crocidura species known to occur in the country. Both new species are currently known only from the Ethiopian Highlands. Furthermore, we provide new geographical records and discuss biogeographical patterns in the country. New molecular data, even if based primarily on mitochondrial cytochrome b, suggests substantial divergence within afrotropical Suncus megalura, suggesting that the East African lineage might be considered separated at the species level - Suncus sorella (Thomas, 1897), stat. nov. Molecular data support a monophyly of the Glade, grouping most Crocidura species endemic to Ethiopia (the East African subclade of the Old World Glade), but also indicates additional colonisations of Ethiopian Plateau from East and Central Africa in the past. The remarkable number of endemics shows that Ethiopia is an important centre for the Crocidura radiation, as is the case for other groups of non-flying terrestrial vertebrates.
Abstract. Small rodents are increasingly gaining importance as agricultural pests, with their distribution and abundance known to vary across landscapes. This study aimed at identifying ecological factors in the landscape that may influence small rodent distribution and abundance across agricultural landscapes in Uganda. This information may be used to inform the development of adaptive control measures for small rodent pests. Small rodent trapping surveys were conducted in three agro-ecosystem landscapes: Butaleja, Mayuge and Bulambuli districts in Eastern Uganda between November 2017 to June 2018 covering both dry and wet seasons. Data on small rodent abundance and richness, vegetation characteristics, land use/cover characteristics, farm management practices and soil characteristics were collected from quadrats. Additionally, Geographic Information System and remote sensing were used to determine vegetation characteristics (Normalized Difference Vegetation Index – NDVI) and land use/cover from satellite images. Our results showed that crop field state (including hygiene, crop type and growth stage) is the most important variable with an overall relative importance of 34.4% prediction value for the abundance of Mastomys natalensis across the landscape studied. In terms of number of species encountered (species richness), results showed field crop status scoring highest with an overall relative importance of 39.8% at predicting small rodent species richness. Second in importance for overall rodent abundance was percentage composition soil silt particles with 15.6% and 18.1% for species richness and abundance respectively. Our findings have important implications for small rodent management, where land use characteristics, especially field crop state, is a critical factor as different conditions tend to affect rodent abundances differently. The study thus recommends that control efforts should be planned to consider field crop state; i.e. field hygiene where fields should be kept free of weeds to eliminate potential rodent breeding/habitation sites thus lowering rates of reproduction and population increase.
A study was conducted in Mabira Central Forest Reserve in Uganda to determine rodent species composition, relative abundance, and habitat association. A total of 1,030 rodents belonging to 14 species were captured on 10,584 trap nights. Rodent species recorded include: Lophuromys stanleyi, Hylomyscus stella, Praomys jacksoni, Mastomys natalensis, Lophuromys ansorgei, Lemniscomys striatus, Aethomys hindei, Mus triton, Mus minutoides, Deomys ferrugineus, Gerbilliscus kempi, Rattus rattus, Grammomys kuru, and Hybomys univittatus. Overall, L. stanleyi (23.7%) was the most dominant species followed by H. stella, P. jacksoni, and M. natalensis. Species richness and evenness was highest in the regenerating forest habitat and least in the intact forest habitat. Rodent abundance was significantly affected by habitat type. The regenerating forest habitat had the highest number of animals, while the lowest numbers were observed in the depleted forest habitat. Species diversity was higher in regenerating forest habitat and lowest in the intact forest. The three habitats appeared distinct in terms of rodent species composition and there was a strong association between the two trapping grids in the same habitat type. All ordination plots showed that different rodent species consistently associated with distinct habitats. Habitat type and seasonal changes influenced rodent composition, relative abundance and habitat association. Composition of rodent community reflected the level of habitat degradation and can be used as a proxy for evaluating the biodiversity of lowland tropical forests.
The presence of the parasitic copepod Neoalbionella globosa in the olfactory chamber of a specimen of the catshark Scyliorhinus canicula has been already reported in the literature, but this is the first record from the north-western Mediterranean Sea. Besides confirming this host-parasite association in the Ligurian Sea, the present study aims to describe some effects of the copepod's presence on the olfactory system of S. canicula, thus inferring potential effects of nasal parasites on olfaction. The copepod was accidentally found during a sampling campaign. The copepod, a mature female with well-developed egg sacs, parasitized the right olfactory rosette; the rosette presented visible swelling in some of the olfactory lamellae while, histologically, restricted edema was detectable close to the zone of attachment. The ipsilateral olfactory bulb, which receives the primary olfactory afferences, had a smaller number of cells and smaller neuron density compared to the contralateral bulb and to the average values for non-parasitized specimens of the same size. The results suggest that, although the olfactory rosette does not seem severely damaged, the presence of the parasite could deeply affect the highly efficient water flow within the nasal chamber, potentially causing partial olfactory impairment.
A good knowledge of food resource utilization is essential to understand how most wild ungulates meet their seasonal requirements in order to improve conservation of endangered taxa. Using faecal sampling, the diet of Gazella cuvieri has was investigated in the Djebel Messaad Mountain (M'sila Province, Algeria) from September 2013 to August 2014. A microhistological analysis method revealed that gazelles ate 29 species of plants during the year. The grass Stipa tenacissima and the shrub Artemisia herba alba were the major food items throughout the year. The highest diversity was recorded in spring (17 taxa) despite a large consumption of Helianthemum lippii, the lowest in a dry summer (nine species), including the major consumption of the shrubs Phillyrea media and Thymus algeriensis, together with Artemisia herba alba, Stipa tenacissima and Stipa parviflora. An average relative numerical abundance of 50.5 % of the diet comprised shrubs and trees, mainly including A. herba alba, T. algeriensis and Cistus libanotis. Grasses and forbs accounted for 29.4 % and 20.1 % respectively. Based on this study, this gazelle species can be classified as an intermediate feeder (i.e. browser-grazer).
The red goral is an endangered species with a small population and narrow distribution in China. The only captive population (21 individuals) is held in Shanghai Zoo, China. Demographic and genetic analyses were carried out to assess the status of this captive population and put forward conservation and management proposals. Population status was assessed on the basis of studbook records from 1981 to 2016. The population size grew from seven (three males, four females) to 31 (19 males, 12 females) in 2012 (lambda = 1.06) and 21 (17 males, four females) in 2016 (lambda = 0.91). From 1981 to 2016, a total of 81 births (45 males, 36 females) and 68 deaths (32 males, 32 females, four unknown) occurred. The mean kinship (MK) of the population is 0.2614 and the average inbreeding index is 0.2037. Parturition mainly occurs in May, June and July, and deaths occurred in January, February, July and November. In addition, the genetic diversity of this population was analysed on the basis of nine microsatellite loci. The results revealed that 14 primer-amplified bands were found; nine of them were stable, with four loci highly polymorphic (polymorphic information content, PIC > 0.05), three moderate (0.25 < PIC < 0.5), one low (PIC < 0.25) and one monomorphic (PIC = 0). In total, 34 alleles were detected from eight microsatellite loci, with the number of alleles per locus (A) ranging from 3-6 (<(x)over bar> = 4.250), and the effective number of alleles (Ne) from 1.245 to 3.862 ((x) over bar = 2.529). The observed heterozygosity (H0) varied from 0.143 to 0.857 ((x) over bar = 0.562), and the expected heterozygosity (He) from 0.201 to 0.755 ((x) over bar = 0.550). The polymorphism information content (PIC) varied from 0.188 to 0.705 ((x ) over bar = 0.500). The results indicated a moderate level of genetic diversity among the red goral population in Shanghai Zoo.
