Zoological Studies最新文献

Despite the severe decline that arthropod communities are experiencing worldwide, there are still basic scientific knowledge deficits that are preventing policymakers from implementing optimal decisions for their conservation. Chorological maps, fundamental conservation tools, are not available for most species or are not updated periodically in an agile way. Limited funding or an unaffordable workforce are some of the impediments to surveying species distribution. To address these challenges in the near term, several solutions have been proposed. One option involves engaging citizens in the collection of data, a method not commonly employed for studying spiders. Here, the distribution of the only spider species protected by EU legislation, the elusive Iberian endemism Macrothele calpeiana Walckenaer, 1805 (Macrothelidae) is updated by using traditional sources, but mostly citizen records, both in its native range and for the whole European continent, given that the species has frequently been unintentionally exported to various countries. The native range has been slightly expanded and currently occupies 156 UTM 10 × 10 grid cells, which means ca. 2.7% of the total area of the Iberian Peninsula. Citizen collaboration proved decisive, especially to generate recent information in a short period of time: over just the last 10 years, data from third parties covered 35 grid cells, 17 of them new to science. On the other hand, M. calpeiana has been reported as non-native in eight different countries. In some of them, such as France and Italy, the reports are recurrent. The outcomes of the methodology used in the study were highly encouraging, showcasing its potential for implementation by budget-constrained administrations to effectively monitor this species of conservation concern.

Climate change and biological invasions have had significant impacts on ecosystems and biodiversity. To assess how environmental changes affect two key invasive snails-Pomacea canaliculata and Pomacea maculata-in East Asia, we built species distribution models (SDMs) and ecological niche models. These apple snails (Gastropoda: Ampullariidae) have negatively impacted ecosystems and human health. Understanding their distribution is crucial for containing invasions under current and future climates. Our findings indicate that these two species occur primarily in China and Japan but occupy different suitable habitats, and the highly overlapping niches suggest interspecific competition. P. canaliculata is more adaptable extreme environments. The projections show that the sustainable development pathway (SSP126) best limits these invaders by suppressing reproduction and dispersal. This study provides predictive information that can be utilized to reduce the invasiveness and spread of these two Pomacea species. To prevent further increases in suitable habitat, control measures should be taken as early as possible.

Opoptera Aurivillius, 1882 belongs to the tribe Brassolini and comprises 10 species. The white belt owlet butterfly Opoptera fruhstorferi (Röber, 1896) is endemic to the Atlantic Forest, occurring in the southeast and south regions of Brazil. Morphological studies, including detailed descriptions of immatures and aspects of the natural history of Opoptera, remain poorly documented. This study aims to 1) describe for the first time the morphology of the immature stages of O. fruhstorferi; 2) provide a complete view of its life cycle; 3) report tritrophic plant-host-parasitoid interactions; 4) compile records of Brassolini parasitoids from the literature. These data expand the understanding of the natural history of Opoptera, a genus that still has several gaps to be filled. This study also contributes to the systematics of Neotropical butterflies.

Scylla olivacea is a commercially important species in the Indo-Pacific region, currently facing growing pressures from anthropogenic stressors. This study compares populations from the Indian Ocean (Andaman Sea) and the Pacific Ocean (Gulf of Thailand) to assess how different oceanic region and seasonal conditions influence key reproductive traits. By examining parameters such as sex ratio, size at first maturity, fecundity, and gonadosomatic index (GSI), the study aims to identify the differences that can inform targeted and sustainable management strategies. Crab samples were collected monthly from five sampling sites along the coast of the Indian Ocean (Ranong, Satun and Trang provinces) and the Pacific Ocean (Pattani and Surat Thani provinces) using traditional crab traps by local fishermen from April 2022 to May 2023 and subsequently analyzed in the laboratory. Results indicated that crabs from Ranong province, the Indian Ocean, exhibited smaller body sizes and values of most reproductive parameters (p < 0.01). The fecundities were 1.03 × 106 and 1.49 × 106 for crabs from Ranong and Pattani provinces, respectively. Positive relationships were found between internal carapace width (ICW), carapace length (CL), abdomen width (AW), and body weight (BW) with ovary weight (OW). Mature females, based on gonad development stages III and IV, were present year-round at both oceanic coasts. Peak abundances were found in November at both sites. High GSI levels were recorded in April and June for Ranong province (3.05 ± 1.97 to 10.97 ± 1.96) and February and June for Pattani province (3.19 ± 1.72 to 10.52 ± 1.71). The estimated sizes at maturity (M50) for female/male of S. olivacea varied across locations with smaller sizes observed from the Indian Ocean viz., 78.0/83.1 mm, 64.0/79.2 mm and 81.9/80.6 mm in the provinces of Ranong, Satun and Trang, respectively and 92.3/93.2 mm and 96.9/96.8 mm in Pattani and Suratthani, respectively. The sex ratio also indicated variations across region, with male:female ratios of 1:0.92, 1:0.78, 1:0.77 and 1:1 in the provinces of Pattani, Ranong, Satun and Trang. It is thus concluded that the oceanic region affects reproductive characteristics of S. olivacea and these findings can be applied to highlight the importance of localized management strategy for a sustainable use of mud crab resources.

Spiders play a pivotal role in ecosystems, serving as predators to regulate populations of small organisms. They commonly exhibit body color polymorphism which could be due to a combination of environmental factors, adaptation, or genetic drift from population subdivision. This polymorphism, in turn, could affect their behavior and prey capture efficiency. Certain morphological traits may be unique to specific subregions, suggesting possible subspecies classification. In this study, we examined morphological polymorphism in the giant wood spider, Nephila pilipes, in Thailand, particularly focusing on leg variation and genetic variation at the cytochrome c oxidase I (COI) gene. We used partial sequence of the COI gene for our samples and constructed a phylogenetic tree by including other species. We explored the relationship between morphological polymorphism, COI genotype, and geographic distribution. Our findings categorized female N. pilipes into seven types based on legs I and IV, with no correlation to geographic region. The N. pilipes specimens formed two clades, each containing all leg types and collection regions, consistent with low genetic differentiation within the species. Trichonephila antipodiana specimens formed three clades while all Argyrodes flavescens specimens were grouped into a monophyletic clade. Additionally, Nephila kuhli, previously suggested to be a melanic morph of N. pilipes, was also included in the N. pilipes cluster, with a low genetic distance. Our results suggest that the leg variants in N. pilipes represent polymorphism within the species rather than distinct biospecies.

A new stygobitic amphipod species of the genus Spelaeogammarus is described from a cave in the municipality of Morro do Chapéu, in Bahia, northeastern Brazil, increasing the total number of species in the genus to eleven. Spelaeogammarus quilombola sp. nov. shares similarities primarily with Spelaeogammarus spinilacertus, S. bahiensis, and S. trajanoae, but can be distinguished from its congeners by specific morphological and morphometric traits. An updated comparative table highlighting the diagnostic characteristics of Spelaeogammarus species are also provided. Additionally, we offer a supplementary description of S. bahiensis da Silva Brum, 1975, the type species of the genus. Finally, we discuss the habitat characteristics and the threats facing both species addressed in this study. Given its high endemism, this new species holds particular significance for biogeographical and conservation studies.

The function of ecdysone in promoting molting is widely known in arthropods. Moreover, in insects, ecdysone synthesis in the ovary is involved in reproduction and development. In crustaceans, some studies conducted in species with the molt linked to mating have shown that ecdysone produced by the Y organ stimulates ovarian maturation, but scarce evidence about the capacity of the ovary itself to synthesize ecdysone is currently available. The present study provides the first evidence of the expression of a putative shadow gene (sad, cytochrome P450 CYP315A1), involved in the ecdysone synthesis pathway, in the ovary of the estuarine crab Neohelice granulata, considered a derived species with the molt not linked to mating. The obtained results provide the first evidence for future studies testing the hypothesis that during the intermolt period, the mature ovary of females synthesizes ecdysone to locally act on the female vulvae to promote its decalcification, allowing mating. These results are discussed considering phylogenetic relationships among Arthropoda.

Caenorhabditis species diversity has been surveyed in several places around the world and tends to be higher in subtropical and tropical regions. Vietnam is a long country with complex topography and a climate largely influenced by the northeast monsoon from the Siberian plateau. Here, we report the first Caenorhabditis survey in Ta Kou Nature Reserve located in south-central Vietnam, where we have found two isolates of a new species, Caenorhabditis sp. 71. Whole genome skimming of one isolate using a combination of the Oxford Nanopore Technologies MinION long read and Illumina short read sequencing platforms allowed us to assemble a complete mitochondrial genome that is 13,654 bp in length. Annotation of the mitochondrial genome revealed 12 protein coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and 1 control region. Phylogenetic analysis, based on the concatenated sequences of the 12 mitochondrial protein coding genes, suggests that Caenorhabditis sp. 71 is the sister species to C. imperialis. Our findings not only contribute to the understanding of Caenorhabditis diversity in Vietnam but also highlight the ecological significance of isolated habitats, such as Ta Kou Mountain. These fragile environments are essential for biodiversity conservation and require dedicated protection to preserve their unique and diverse ecosystems.

We describe the complete larval development of the pedunculated barnacle Capitulum mitella, using both light microscopy and scanning electron microscopy. This includes all six naupliar instars and the final cypris stage. Many previous accounts on the development of barnacle larvae suffer from a shortage in detail and habitually use terminologies that are either inconsistent or hard to compare with those used for other crustaceans. We therefore propose and use a new, completely standardized terminology to enable comparison both within barnacles and with larvae of other crustaceans. Rather than a stage-by-stage description, our account follows changes in specific features during larval development. The morphological, ecological and phylogenetic significance of these characters is discussed. Special attention is paid to the feeding apparatus and how it may have undergone adaptive evolution in response to changes in the availability of food items through geological time. C. mitella is universally agreed to be placed lower in the barnacle phylogeny than acorn barnacles (Balanomorpha), and fossil forms very similar to this species can be traced back to the Upper Jurassic. This makes C. mitella central to understanding the large-scale evolution within barnacles.

In recent decades, taxonomy has been significantly improved by integrating molecular techniques with classical morphological methods, leading to the discovery of cryptic species. On the other hand, molecular datasets by themselves are ineffective in several types of research without basic taxonomic studies, as the ecological and biological roles of a given species cannot be determined without an accurate name. DNA barcoding libraries are widely used as identification tools by non-specialists to overcome the taxonomic impediment, but they fail when basic taxonomic studies are insufficient and faunistic inventories are lacking. South European microlepidoptera are poorly studied, with the exception of a few families such as Depressariidae. We tested the effectiveness of the DNA barcoding library for this family to identify 174 specimens collected in southern Italy, where faunistic studies are very limited. All specimens were successfully barcoded, and 95% of them were assigned to 47 species, 43 of which correspond to a Barcode Index Number (BIN). Four additional species shared a BIN but were still clearly separated into different clusters at within-BIN resolution. Only seven specimens belonging to four BINs remain unnamed, and ad hoc studies are needed to clarify their status. The regional fauna was enriched by 37 species, three of which are new for the Italian mainland and 21 for peninsular Italy, demonstrating the usefulness of the DNA barcoding library in assessing local diversity and overcoming the taxonomic impediment. Improving taxonomic studies is crucial for utilizing molecular datasets to depict ongoing macroecological dynamics, highlight species richness trends, and identify changes in species assemblages.