Comparisons of D. lamillai with other related species have been made, yet a proper comparison with the morphologically similar Zearaja brevicaudata, the most abundant longnose skate in the Southwest Atlantic, was not conducted. Morphological and molecular analyses were employed to ascertain the species identity of these organisms. Principal Component Analysis was applied to evaluate linear morphometric variables in both the holotype and paratypes of D. lamillai and 69 specimens of Z. brevicaudata. Furthermore, the comparative analysis encompassed thorn patterns, denticle distributions, color variations, and clasper morphologies. The study of body proportions and any other singular trait did not reveal any distinctions between D. lamillai and Z. brevicaudata. The molecular comparison of Cytochrome oxidase subunit I (COI) and NADH dehydrogenase subunit 2 (ND2) sequences was conducted. The Maximum Likelihood (ML) method for each marker revealed that *D. lamillai* sequences clustered with *Z. brevicaudata* sequences, demonstrating a Kimura two-parameter molecular distance that was less than expected for unrelated species. HIV phylogenetics The Automatic Barcode Gap Discovery method and the Bayesian Poisson tree process model were employed on COI sequences to explore species delimitation, and their findings were consistent with the results of maximum likelihood analyses. Conclusively, the examination of the results signifies that there were no observable morphological or molecular differences among these named species of the valid genus Zearaja, thus reinforcing the idea of their conspecificity. Henceforth, Z. brevicaudata will be recognized as the senior synonym of D. lamillai.

*Stolephorus taurus* sp., the Bengal Spined Anchovy, holds a significant ecological role. The northern Bay of Bengal provided 21 specimens used to characterize November. Stolephorus dubiosus Wongratana, 1983, which has been subject to taxonomic redescription, demonstrates a close affinity with the newly discovered species. In both species, a predorsal scute, a spine on the pelvic scute, a maxilla reaching close to or barely missing the posterior opercle, at least 25 gill rakers on the lower portion of the first gill arch, and a double black line formation on the dorsum behind the dorsal fin are present. Differing from S. dubiosus, the new species demonstrates a distinct characteristic: a longer pelvic fin, its posterior edge situated past the vertical line running through the origin of the dorsal fin. The dorsal fin's origin does not usually extend vertically, complemented by a greater length in the pectoral fin, and particularly noticeable second and third dorsal fin rays, alongside the second and third anal fin rays, and a notably broader interorbital width. Stolephorus taurus, a species, was illicitly removed. Nov. shares a close evolutionary relationship with Stolephorus baganensis Delsman, 1931 and S. dubiosus, despite exhibiting at least a 2% mean p-distance divergence in their mitochondrial cytochrome c oxidase subunit I (COI) gene sequences. A phylogenetic study of the prepelvic scutes in Stolephorus implies that the initial condition likely involved six scutes, eventually decreasing to either five or four. Amongst the recent evolutionary changes, there's been a decrease in the lineage of Stolephorus taurus sp. Each sentence in this JSON schema's list is rewritten, with a novel structure, compared to the original.

Widespread throughout the tropical Indo-West Pacific region, Oxyurichthys is a genus of goby. Oxyurichthys species predominantly inhabit estuarine and coastal marine environments. Fish, commonly commercial species, are collected via trawling to meet the demands of the market within Southeast Asia. Fish mitogenomes offer substantial insights into species relationships and historical development; nonetheless, the mitogenome of Oxyurichthys species continues to elude researchers. Characterizing and comparing the mitogenomes of the Oxyurichthys gobies, O. ophthalmonema and O. microlepis, is the focus of this research. For O. ophthalmonema, the mitogenome size was 16504 base pairs; correspondingly, O. microlepis's mitogenome size was 16506 base pairs. The mitogenomes from these two species presented a similar gene complement and architectural arrangement. Both subjects displayed 37 genes and a regulatory zone. Safe biomedical applications Previous documentation of goby mitogenomes reveals similar gene features and base composition to the two Oxyurichthys mitogenomes. BMS-232632 The control regions of both species were found to contain the conserved blocks CSB-1, CSB-2, CSB-3, and CSB-D, which are typical features. The phylogenetic analysis, employing a concatenation method on 13 protein-coding genes and 2 rRNA sequences, indicated that the two Oxyurichthys species are closely related and sister taxa to species from the Sicydium, Sicyopterus, and Stiphodon genera. Previous evolutionary studies of gobies, utilizing alternative molecular markers, are substantiated by the findings of the present investigation.

Pseudocypretta amor, an intriguing species, continues to be a focus of scientific inquiry. A list of sentences, each rewritten with a distinct grammatical structure and vocabulary, is provided in this JSON schema. The species, distinguished by carapace spots resembling the word 'Love,' is documented here from all-female populations inhabiting the four major Brazilian floodplains. The new species is evaluated in contrast with the already documented two other species within the genus P. maculata Klie (1932), the type specimen, and P. lineata Ma and Yu (2020). The two species, until recently restricted to Southeast Asia and China respectively, have extended their range to include South America, highlighting a considerable geographic expansion for the genus. This genus and species are explored concerning several morphological traits, prominently the existence of marginal septa in the valves, the candonid type T3 featuring separated third and fourth segments, and the caudal ramus' reduction to a flagellum or complete absence. Recognizing the close evolutionary link to Cyprettadopsis Savatenalinton, 2020, the taxonomic placement of Pseudocypretta is revised, transferring it from the Cyprettinae to the Cyprettadopsini tribe within the Cypridopsinae. The presence of candonid type T3, typically exhibiting a pincer-shaped terminus due to the fusion of its 3rd and 4th segments, within the Cyprididae and Notodromadidae is examined further.

Male morphotypes within a crustacean population are sometimes associated with the emergence of social dominance hierarchies. The decapod crustacean genus Macrobrachium currently features the highest number of species on record that demonstrate hierarchical development. Male social dominance is reflected in the morphological characteristics observed within Macrobrachium olfersii populations. This study investigated the hypothesis of male morphotypes in M. olfersii, utilizing morphometric and morphological examination of the chelipeds. Sampling efforts, conducted at seven points along the Jequitinhonha River in Northeast Brazil, spanned the time period beginning in March 2018 and concluding in October 2021. From the collection, 264 male specimens were extracted, with carapace lengths (CL) falling within the range of 401 mm to 2370 mm. Morphological sexual maturity was determined to be associated with a size of 895 mm, as measured by the standard length (CL). The morphometric and morphological data collectively demonstrated the presence of three adult male morphotypes, which were labelled M1, M2, and M3. The different morphotypes were primarily defined by the differences in size, shape, and morphology of the largest cheliped belonging to the second pair of pereopods. The morphometric relationships of the three morphotypes displayed substantial variation (p < 0.001), particularly when comparing morphotype M3 with morphotypes M1 and M2. The shape of the propodus exhibited significant variation. A significant disparity (p < 0.001) existed between morphotypes regarding spine traits and their angulation, where the propodus of morphotype M3 demonstrated greater robustness and a higher density of spines than the other morphotypes. Competition for resources favors dominant individuals whose heightened social standing is complemented by a highly developed cheliped. These individuals, possessing this specific morphological characteristic, often exhibit an advantage during conflicts, ensuring access to the best resources, encompassing shelter, food, and mates. The biology of *M. olfersii*, along with that of the Macrobrachium genus, is advanced by our research, especially concerning the behavior of social dominance within the group. Correspondingly, by providing a comprehensive account of these morphotypes, employing a collection of complementary morphological and morphometrical methodologies, one can access the diverse morphologies of M. olfersii males, and subsequently validate a life history attribute common among various Macrobrachium species.

The world's biggest water masses serve as the natural habitat for the globally distributed fin whale. Malaysia and its tropical Southeast Asian counterparts suffer from a shortage of fin whale literature, thus creating uncertainty about their regional distribution. To determine species identity, possible dietary components, and trace element levels, the fresh skin and blubber samples of a deceased fin whale stranded on the coast of Sabah (Borneo, Malaysia) in the South China Sea were analyzed in this study. Upon examination of the DNA profile, the whale was identified as belonging to the species Balaenoptera physalus. A detailed investigation into the cytochrome b gene sequence showed a close evolutionary relationship to the southern fin whale (Balaenoptera physalus quoyi). The data indicates that fin whales do, indeed, migrate to the warm tropical waters, and their uninterrupted global distribution stretches into the equatorial region. Pelagic plankton formed a significant part of the whale's diet during its migration in the tropical South China Sea, as evidenced by the predominant fatty acid profiles, including C18:0, C16:1, C18:1n9t, and C16:0. The pelagic feeding habits of whales necessitate their offshore presence, explaining their infrequent sightings in shallow coastal areas during migration in these waters. Concentrations of potassium, calcium, scandium, magnesium, and aluminum varied between 0.45 and 7.80 grams per gram, contrasted with chromium, cadmium, arsenic, and lead, which were either present in minute quantities or not detectable.