Prey use a variety of anti-predator behavior, including alarm calling and approaching predators, and may adjust these behaviors by evaluating their benefits and costs. However, it remains unclear how prey expresses anti-predator behavior across seasons, when both breeding status or predator diet may influence perceived risk. We conducted nine-minute playback surveys (six-minute quiet period and subsequent three-minute playback) using calls of Collared Owlet (Glaucidium brodiei), a diurnal owl that preys on passerines, at 93 sites during breeding season and non-breeding season in Taiwan. We quantified whether the small passerine birds approach and make alarm call or not to quantify mobbing response. We found that probability of making alarm calls did not differ between seasons (30.88% and 29.15% in breeding and non-breeding season, respectively), whereas probability of approaching was higher in breeding (25.63%) than in non-breeding season (13.28%). To verify that responses were specific to predator cues rather than to loud vocalizations in general, we conducted supplementary playbacks using calls of a non-predatory species, Taiwan Barbet (Psilopogon nuchalis), which elicited markedly lower mobbing responses. Together, these results indicate that small passerine birds mob in both seasons but reduce the use of higher-risk behaviors against predators during the non-breeding season, consistent with seasonal variation in predation risk.
Four species of tardigrades have been found in the meiofauna communities of the seagrass meadows and adjacent areas off the coast of Vietnam. For two of them, Batillipes binhdinhicus sp. nov. and Batillipes ampullus sp. nov., integrative descriptions are presented. Batillipes binhdinhicus sp. nov. belongs to the B1 subgroup of species by having toe 3 shorter than toe 4 on legs IV, while Batillipes ampullus sp. nov. with toes 3 and 4 on legs IV of equal length belongs to the A group of species. Batillipes binhdinhicus sp. nov. can be distinguished from all previously described species by a set of features: very long cephalic cirri and leg sensory spines, both with swollen tips, presence of a single pair of conical lateral body projections between all pairs of legs and simple triangular caudal appendage. The distinctive features for Batillipes ampullus sp. nov. are short sensory organs on the fourth pair of legs, which consists of two parts and have swollen tips with a tuft of additional sensory filaments that are structurally similar to those found on the cephalic appendages. In addition, Batillipes ampullus sp. nov. does not have noticeable lateral body projections between the legs, and the body ends in a semi-circular tail appendage. Based on the obtained data on the nucleotide sequences of 18S rDNA and 28S rDNA, the distinction between the new species was confirmed.
Louse flies (Hippoboscidae) are ectoparasitic dipterans found on the body of birds and mammals. They have been reported from a wide geographic range, and eight species from four genera have been recorded from the Nansei Islands, a stretch of islands lying between Southwestern Japan and Taiwan. However, due to difficulties in obtaining samples, we are yet to have a complete understanding of the fauna and our knowledge on their distribution remains limited. Here, we collected louse fly samples from two scops owl species (Otus elegans and O. semitorques) from three islands within the Nansei Islands, and identified them based on their morphological characteristics. Three species, Ornithoica exilis, Ornithomya avicularia and Icosta amamiensis, were reported with different appearance of species on each island. This is the first record of Om. avicularia for Okinawajima, and the first record of this family for Haterumajima (Oc. exilis and Om. avicularia) and Minami-Daitojima (Om. avicularia). We also sequenced mitochondrial COI gene to estimate their phylogenetic positions, and also to understand the inter-insular population structure of Oc. exilis and Om. avicularia, which were collected from multiple islands. We found no inter-insular genetic differentiation between the populations, despite the host owls having low dispersal ability, indicating low host specificity and host switch of these species. We provide a complete list of all 422 specimens examined and identified in this study, along with records of phoresy by mites and chewing lice. We also present an updated key to bird-parasitising Hippoboscidae species reported from the Nansei Islands and unreported potential species.
Fireflies (Coleoptera: Lampyridae) serve as bioindicators due to their sensitivity to environmental changes; however, their ecological distribution remains insufficiently documented. The Tacaná Volcano in Chiapas, Mexico, represents a biodiversity hotspot with diverse altitudinal ecosystems. This study investigates the altitudinal distribution of fireflies in this region through systematic sampling at four sites ranging from 278 to 2181 m a.s.l. between July and November 2023, employing both aerial nets and Malaise traps. A total of 226 specimens, representing 20 species across seven genera and five tribes, were identified. The greatest species richness was observed at mid-elevations (740-1191 m a.s.l.), particularly in shade-grown coffee plantations, where humidity and canopy cover emerged as significant environmental variables. Species richness was quantified using Hill numbers, while the Jaccard index assessed compositional similarities among sites. Generalized linear models (GLMs) and canonical correspondence analysis (CCA) evaluated the relationships between firefly abundance, species richness, and environmental parameters. Firefly abundance demonstrated positive correlations with temperature, humidity, and canopy cover, while precipitation exhibited a negative correlation. Nevertheless, no single environmental variable was identified as a definitive determinant of species richness. New distributional records reinforce the conservation significance of the Tacaná Volcano. Malaise traps proved to be an effective complement to traditional sampling techniques, facilitating the capture of diurnal and non-bioluminescent species. The highest species diversity and abundance were recorded in shaded coffee plantations, which provide stable microclimatic conditions conducive to firefly populations. Conversely, lower diversity was documented at the lowest and highest elevations, likely attributable to habitat constraints. This study highlights the importance of continued research to elucidate the ecological drivers influencing firefly distribution and to inform conservation strategies. Given the identification of novel species and new distributional records, the Tacaná Volcano should be recognized as a priority site for biodiversity conservation and entomological studies.
Heart urchins of the genus Faorina are now endemic to the Indo-West Pacific, but their fossils were previously known from the Miocene of Mediterranean, indicating a wider geographic distribution in the past. Here we describe Faorina mizoramensis sp. nov. from the Lower to Middle Miocene Bhuban Formation (Surma Group) in northeastern India, identified by their meridoplacous plating in interambulacrum 1 adorally. These fossils demonstrate that the distribution of Faorina had reached the eastern Indian Ocean (or Ceno-Tethys) by the Early to Middle Miocene. This study shows that Faorina likely expanded widely, extending into the Mediterranean during the Miocene. Following the closure of the Tethyan Seaway, they experienced local extinction. Today, they are restricted to Taiwan, southern China, Vietnam, Australia, Sulu Sea, Burma, and the Andaman Islands. We therefore hypothesize that Faorina may have originated in the Mediterranean, with the Indo-West Pacific later becoming a refugium for this genus and some of the tropical to subtropical Ceno-Tethyan echinoid faunas.
Seven late juvenile stages or young males, two late juvenile stages or males fixed in the process of moulting, three stage-1 and seven stage-2 females, and 17 juvenile specimens of Campyloderes cf. vanhoeffeni Zelinka, 1913 from various locations as well as a late juvenile or male and a juvenile specimen of Ryuguderes casarrubiosi Cepeda et al., 2022 were studied by light microscopy. The investigation yielded important insights into the life history of mainly the former species, viz, (1) establishment of clear distinctive characters between late juvenile and female as well as more maturated male life history stages, (2) the principal developmental series of juvenile stages, (3) development of spines via anlagen and modified spines, and (4) dissolution of septa in the primary spinoscalids of the head during moulting.
The present paper provides first data on the fauna of Holothuroidea of the Emperor Seamount Chain (ESC, northwestern Pacific). Samples were collected using ROV Comanche 18 from four guyots, Kinmei, Koko, Nintoku and Ojin, in 2019 and 2021 at depths from 750 to 2240 m during two cruises of RV Akademik M.A. Lavrentyev. Sixteen species were recognized. Orders Elasipodida and Synallactida were the most diverse. Here we provide morphological descriptions and molecular data on COI and 16S rRNA for nine species belonging to eight genera and also for three taxa identified to the family level. One genus and two species are described as new: Parvathuria dautovae gen. et sp. nov. and Peniagone koko sp. nov. Two representatives were assigned to the genus Hansenothuria; we discuss the phylogenetic position of this genus based on molecular data. Only one of the recorded taxa is known outside the Pacific Ocean. More than a half of the examined species has the closest genetic affinity to holothuroids from the Pacific, indicating predominantly local origin of the ESC holothuroid fauna.
In order to gain insight into the field of embryonic developmental biology, the study of scute patterning in green turtles (Chelonia mydas) has been a subject of considerable attention. Numerous factors, including genetic, environmental, and physiological are known to affect the formation of scute patterns. The aim of this study was to investigate the relationship between estimated clutch mass (ECM), volume of the sand at the top of the eggs (sand volume), and nest depth (ND) with the number of individuals exhibiting non- modal scute patterns (NMSP) at Alata beach in the eastern Mediterranean during the 2009 nesting season. We also conducted an investigation into the prevalence of NMSP frequencies. Using generalized additive mixed model (GAMM) analyses, we evaluated 5 covariates, including ECM, sand volume, ND, distance from sea and vegetation, that could affect NMSP. A total of 1,064 hatchlings from 33 nests were examined, and 801 exhibited the modal scute pattern, while 263 exhibited NMSP. The prevalence of NMSP was found to be 24.8%. The GAMM model showed a significant relationship between ECM and the frequency of NMSP, which was supported by correlation. ECM was found to account for 26% of the observed variation in the model, while ND and sand volume were found to account for less. The limited effect of ND and sand volume on NMSP, when considered alongside the modest proportion of ECM alone in explaining NMSP frequency, suggests that ECM may play a role in NMSP frequency with other environmental factors. This is the initial study to provide preliminary information into the association between ECM and NMSP frequency. In future studies, experimental studies involving ECM and environmental factors will be crucial in terms of revealing the contribution and joint role of ECM on NMSP frequency.
The taxonomy and systematic position of the Eastern Asian wolf spider Lycosa coelestis L. Koch, 1878 are revised using an integrative approach. Our study highlights distinctive morphological and molecular differences that separate this species from the generotypes of Lycosa Sundevall,1833 and Hogna Simon, 1885, to which L. coelestis was previously assigned. Based on these findings, we establish a new monotypic genus, Erranticosa gen. nov., to accommodate this species, namely E. coelestis comb. nov. We also discuss the results of a preliminary molecular phylogenetic analysis of the subfamily Lycosinae, including Erranticosa gen. nov. Additionally, based on morphological examination of the type material, we reject the synonymy of Lycosa subcoelestis Fox, 1935 with E. coelestis comb. nov., transferring it to Trochosa C.L. Koch, 1847 as a valid full species, and we establish the new combination, i.e., T. subcoelestis (Fox, 1935) comb. nov. At the same time, we synonymize Foxicosa Roewer, 1960 (type species: Lycosa subcoelestis Fox, 1935), previously considered a junior synonym of Lycosa, with Trochosa. Our findings highlight the need for an integrative taxonomic and systematic revision of Asian lycosid taxa, as many may be overlooked or misclassified.
After ca. 150 years of faunistic and taxonomic research, the branchiopods (Crustacea: Branchiopoda) of Central Asia still remain one of the poorly studied groups, despite their importance for freshwater ecosystems. Within the region, the most actively investigated country is Uzbekistan, containing a large diversity of water bodies. However, to date a large body of published literature devoted to the local branchiopod fauna lacks critical reviews. Here, we aim to summarize the existing knowledge of Uzbek Branchiopoda based on previous studies and original samples collected in twelve regions of Uzbekistan. Of 47 branchiopod taxa collected in this study, two species-Camptocercus uncinatus Smirnov, 1971 and Ilyocryptus spinifer Herrick, 1882 (Cladocera: Anomopoda)-are new records for the local fauna. Also, we confirm the presence of four more rare taxa in Uzbekistan and provide a list of branchiopod records for each province of the country. With the new records, the list of Branchiopoda in Uzbekistan contains 107 species, which are unequally distributed within the country: Karakalpakstan has the richest fauna (82 species), followed by provinces of northeast Uzbekistan (40 or more taxa), while local faunas of Kashkadarya, Khorezm, Navoiy and Syrdarya Provinces include fewer than 25 taxa each. Such inequality might be due to several reasons, of which research effort seems to be the most significant. Faunistic compositions of the species-rich provinces appear to be uniform and are similar to those of West and South Tajikistan, comprising high proportions of cosmopolitan, boreal and thermophilic south temperate/ tropical taxa. The best studied cladoceran local faunas of the Karakalpakstan and the Fergana valley resemble that of Tajikistan and, to a lesser extent, those of the Mediterranean countries. Thus, these local faunas together form West Eurasian cluster, which fits the biogeographic pattern observed in the northern Palearctic. However, final conclusions about Uzbek Branchiopoda and similarity of the local faunas should not be made to date, as our study highlights a lack of research in several regions, taxonomic groups (Anostraca, Notostraca, Spinicaudata) and particular water body types (temporary pools, montane water bodies). Also, faunistic composition might be distorted by cryptic endemism or extinction of some branchiopod species due to environmental changes. We hope that the presented checklist will encourage further faunistic, taxonomic and phylogeographic research in Uzbekistan.
The family Scalpellidae is a large family of barnacles containing ca. 200+ nominal species. These barnacles inhabit a wide range of depths, although most species live in the deep sea. These species are dioecious (with large females and dwarf males) or androdioecious (with large hermaphrodites and dwarf males), with one or more dwarf males settling in a specific location (the receptacle) in the larger individuals. We studied the reproductive ecology of six dioecious scalpellid barnacle species in the deep sea, which differ in size and habitat depth. Intraspecific analyses revealed that there was a positive relationship between female size and egg number in all the species, but no significant relationship existed between female size and egg size. No trade-off was detected between the size and number of eggs in a brood. Moreover, there was a positive relationship between female size and the number of dwarf males in three species that possess receptacles that carry more than one male. On the other hand, interspecific analyses suggested that female size was positively related to egg size, egg number, and the number of dwarf males. Considering the large variety of reproductive traits and the many species in this group, further research is needed to elucidate how reproductive traits have evolved in scalpellids.
Based on recent studies using both field surveys and laboratory experiments, we review a number of central reproductive traits of the androdioecious barnacle Scalpellum scalpellum. For the first time in any scalpellid species, development has been followed from cypris settlement until a mature dwarf male and compared with the early ontogeny of hermaphrodites. Cyprids settled in preformed receptacles on mature hermaphrodites started to deviate structurally from hermaphrodites almost immediately after attachment. After 14 days they had matured into adult dwarf males that do not resemble any stage in hermaphrodite ontogeny. Therefore, S. scalpellum males are not hermaphrodites arrested in development but the result of a much more profound evolutionary history. Settlement experiments showed that all cyprids are capable of settling and developing into hermaphrodites. Development into males happens only in cyprids attached in receptacles on adult hermaphrodites and must therefore be governed by environmental sex determination (ESD), presumably induced by some chemical factor(s) present only in the receptacle area. We observed mating between hermaphrodites and between a hermaphrodite and its dwarf males. Hermaphrodite to hermaphrodite mating resembles that seen in balanomorphan barnacles, except that adjacent specimens often check their environment with their cirri for the presence of a mating partner. Dwarf male mating is by means of a unique penis structure, made almost exclusively of cuticle and extending from inside the male and bending down into the brood chamber of its partner. This male penis is much larger (relatively to body size) than the structurally very different penis of the hermaphrodite individuals. The hermaphrodite recognizes when the dwarf male extends its penis and arrests its cirral motion so as not to damage or disturb its tiny partner. For the adult hermaphrodites we showed that their allocation of resources to male and female functions is in agreement with predictions from sex allocation theory. As predicted, solitary hermaphrodites allocated fewer resources to male function than those settled gregariously, where one or several hermaphrodite partners are within mating distance. The solitary individuals had both a shorter penis and less developed testes than the gregarious ones. As also predicted, solitary hermaphrodites were more likely to carry males than the gregarious ones.
Speciation can be conceptualized as evolution across dynamic fitness landscapes, where groups of individuals occupy peaks or plateaus that change across space and time. Within such landscapes, gene flows between species can be expected outcomes, which result in the episodic and temporal permeability of species boundaries. Because species recognition and gene flow both arise from the same underlying fitness landscape dynamics, they are emergent, instead of causally linked, properties. Therefore, despite their frequent correlation, studies in systematics should decouple species recognition from the presence or absence of gene flow.
Cholecystokinin (CCK) is a peptide hormone that plays crucial roles not only in the digestive system but also in the central nervous system as a neurotransmitter. Recent research indicate that it is involved in the reproductive endocrine system, inducing the release of follicle-stimulating hormone (FSH) in medaka, Oryzias latipes. The present study tested whether cck expression is involved in the control of maturation in three-spined stickleback (Gasterosteus aculeatus). To that end, castrated and sham-operated males were exposed to short-day (8L:16D) or long-day (16L:8D) photoperiods for 3 or 30 days. Pituitary fshβ was strongly elevated in castrated fish, particularly under short-day conditions, whereas lhβ increased only in sham-operated fish after 30 days under long-day conditions. Castration increased hypothalamic ccka and cckb expression under short days, but decreased ccka after long-day exposure for 30 days. Photoperiod influenced whole-brain and hypothalamic ccks expression differently. Whole-brain ccks levels were generally higher under short days and lower under stimulatory long days, whereas these photoperiodic effects were largely absent in the hypothalamus. These findings suggest that hypothalamic cck genes may participate in feedback regulation on the BPG axis of the stickleback; however, FSH secretion and photoperiodic reproductive control likely involve additional factors.
The diversity of Calocheiridius Beier & Turk, 1952 in Iran is still thought to be uncommon; with only two species reported recently: C. centralis (Beier, 1952), and C. iranicus Nassirkhani, 2014. The current research is devoted to representatives of the genus Calocheiridius from Iran, and led to the identification and description of two novel species: Calocheiridius rectilineatus sp. nov. and C. persicus sp. nov. The novel species were differentiated from their relatives using molecular and morphological analyses, based mainly unique morphometric features, variations in the number of setae along tergite I and the posterior end of the carapace and, trichobothrial patterns, among others. Furthermore, these species exhibit a mitochondrial DNA COI K2P genetic distance that varies from 12.7% to 14% when compared to the nearest relative, C. centralis. Phylogenetic analyses utilising the mitochondrial COI gene and nuclear 28S rDNA, and molecular species delimitation methods, further support description of these new species as separate taxonomic entities. An updated interactive identification key for all species of the genus Calocheiridius, created using DELTA software and based on various numeric and multistate characters, is also provided.
This study examines subtidal brachyuran crabs collected from the offshore sewage discharge site of the Bali wastewater treatment plant, which serves the great Taipei metropolitan areas in Taiwan. It reports seven taxa of brachyuran crabs from Taiwan: three newly recorded species and four others identified only to genus level as the specimens obtained were either adult but partially damaged or juveniles. These species belong to six families and seven genera, including three new genera recorded for the first time in Taiwan: Ceratocarcinus White, 1847, Mariaplax Rahayu and Ng, 2014, and Xenophthalmus White, 1846. The identified species are: Paradorippe sp. (family Dorippidae H. Milne Edwards, 1837), Mariaplax chenae Rahayu and Ng, 2014 (family Hexapodidae Miers, 1886), Nursia sp. (family Leucosiidae Samouelle, 1819, subfamily Ebaliinae Stimpson, 1871), Seulocia sp. (family Leucosiidae Samouelle, 1819, subfamily Leucosiinae Samouelle, 1819), Pinnotheres sp. (family Pinnotheridae De Haan, 1833), Xenophthalmus pinnotheroides White, 1846 (family Xenophthalmidae Stimpson, 1858), and Ceratocarcinus frontodentata (Shen, Dai and Chen, 1982) (family Pilumnidae Samouelle, 1819). Ceratocarcinus frontodentata, M. chenae, and X. pinnotheroides are reported in Taiwan for the first time.
Two new species of freshwater crabs are described from a hillstream in Chixi Town, Taishan City, Guangdong Province, China: Megapleonum taishanense sp. nov. and Cantopotamon chixiense sp. nov. The two new species are sympatric and are similar in size, colour and superficial appearance in the field. Inspection of key morphological characters sets them apart as undescribed species from two different genera. Megapleonum taishanense sp. nov. and Cantopotamon chixiense sp. nov. can immediately be separated from their respective congeners by their unique G1 morphology but also their combination of carapace, maxilliped 3 and male pleon characters. A phylogeny constructed using the mitochondrial COI gene places Cantopotamon chixiense sp. nov. in its own clade as sister to C. yangxiense Huang, Ahyong & Shih 2017 and a previous 16S rRNA gene study has already shown that Megapleonum taishanense sp. nov. represents an independent clade within Megapleonum Huang, Shih & Ahyong 2018, supporting the current taxonomic treatment of both new species.
Two new species of the labeonin cyprinid genus Hongshuia, H. boulobos and H. wangi, are here described from tributaries of the Pearl River Basin, Southwest China. Both share with H. brevibarba the presence of a lower lip with a sector-shaped median lobe (the maximum width positioned at anterior potion of median lobe), distinguishing them from H. microstomata and H. megalophthalmus, which have a roughly rounded median lobe. Hongshuia wangi is distinct from H. brevibarba and H. boulobos in having wider median lobe of lower lip (width 47.8-57.6% of head width vs. 40.5-43.4% in H. brevibarba and 38.5-44.0% in H. boulobos). Hongshuia boulobos further differs from all other congeners in having a lower lip with larger lateral lobes (width more vs. less than one-third of the median lobe width). The study also considers H. paoli as a junior synonym of H. megalophthalmus based on morphological and molecular evidence.
Three new species of freshwater atyid shrimp, namely Caridina chui sp. nov., C. bauhinia sp. nov. and C. argilla sp. nov., are described from Hong Kong, southern China using an integrative taxonomic approach. All three species belong to the C. serrata species group and differ from the other members in characteristics of the rostrum, pereiopods, and male first and second pleopods. Phylogenetic analyses based on mitochondrial COI and 16S rRNA sequences show that the C. serrata species group is polyphyletic and comprises at least four lineages. The validity of the C. serrata species group is discussed and more detailed diagnosis of the species group is proposed. The C. serrata species group sensu stricto is restricted to the nominal lineage containing C. serrata and closely related species, distinguished from other species of the C. serrata species group mainly by having relatively stout carpus of first pereiopod, stout appendix masculina of male second pleopod, and large number of spiniform setae on the uropodal diaeresis.
Trophic interactions between fish and their resources depends on resource availability and interspecific competition. To understand dry-season trophic profiles of a speciose Characiformes assemblage, we performed stomach content analysis to describe diet and determine levels of niche partitioning and morphological adaptations among eight Characiformes species in the dry season in Mata de Itamacaoca, Chapadinha Municipality, State of Maranhão, northeastern Brazil. Insectivory dominated most diets, with Astyanax cf. bimaculatus and Characidium cf. bimaculatum exhibiting the broadest niches. Specialization occurred in Curimatopsis cf. cryptica (85.07% plant material), and there was significant dietary segregation, with indicator species analysis linking Astyanax cf. bimaculatus to piscivory and Knodus guajajara to vermivory. Pianka's index revealed a wide gradient of trophic niche overlap, with the highest overlap observed between Hyphessobrycon piorskii and Knodus guajajara (0.95), and between Holopristis cf. ocellifera and Nannostomus beckfordi (0.96). Morphological PCA associated traits with feeding strategies, including caudal fin length (Astyanax cf. bimaculatus), body depth (Curimatopsis cf. cryptica), and oral gape width (Bario oligolepis). Mixed models confirmed insects and plant material, with a marginally significant effect, as key drivers of dietary variation. Therefore, the assemblage shows high niche overlap combined with diverse trophic profiles. The results demonstrate how dry-season resource scarcity promotes trophic divergence via morphological specialization, with generalists (Astyanax cf. bimaculatus) coexisting with specialists through niche partitioning, which is critical for conservation in this threatened urban-protected area.
