Search Results (117)

Zoological collections are essential for preserving regional biodiversity but often lack taxonomic updates, risking data loss. This work supposes the continuation of a review of the African marine crabs housed at the Crustacean collection of the Museo Nacional de Ciencias Naturales (MNCN) in Madrid. Part I, Heterotremata, revealed that only 21.9% of the specimens were correctly identified. In this new study focused on Thoracotremata species, 197 specimens (59 records) were reviewed, and this new study reveals similar results to Part I: 22.9% of the reviewed specimens were previously correctly identified (less than 29% when considering records), meaning that around 77.2% of the African Thoracotremata specimens housed in the MNCN were either misidentified or not identified at all. This highlights the importance of the taxonomic reviews made by specialists of specimens housed in both historical and non-historical scientific collections. This time we have used DNA barcodes (16S and COI) to confirm identifications or to add new molecular data to species without previous DNA sequences known. DNA sequences (16S and/or COI) were obtained for seven species. It has been a challenge to obtain sequences from specimens preserved 60 to 200 years ago. Full article

The order Decapoda, comprising over 17,000 extant marine species, has maintained a significant association with human societies since ancient times. This prolonged interaction initially centered on their role as a food source, subsequently expanding to encompass a broader spectrum of interests aimed at understanding their unique biological characteristics and diversity. To examine the evolution of the research focus on decapods in Spain, a bibliometric analysis was conducted. The dataset analyzed encompasses literature from various databases, culminating in a total of 913 references pertaining to decapods in Spain without temporal limitations. This analysis facilitated the creation of network maps illustrating the interconnections among primary keywords and authors as well as the progression of scientific output since the earliest recorded study in 1788. The clusters identified in the analysis delineated the principal research topics concerning Spanish decapods, highlighting the predominant areas of study, the most influential authors and institutions, and principal partner-countries establishing collaborative networks. The findings also underscore the prominence of specific journals in the development of the discipline, as well as the weight that commercially significant species have in the scientific literature. Finally, it analyzes the evolution of the research trends and emphasizes the necessity of broadening scientific enquiry to encompass other domains and lesser-known species. Full article

The mitochondrial genome and 5S rDNA are powerful tools for exploring and confirming species identity and understanding evolutionary trajectories. In addition, evaluating the nutritional value of Cambaroides dauricus by determining and analyzing the nutritional components of its muscles could provide essential data for relevant artificial breeding and food processing. In this study, for the first time, we characterized the mitochondrial genome of Cambaroides dauricus using Illumina sequencing technology. The results showed that the mitochondrial genome was a circular genome of 16,215 bp in length. The average sequencing depth of the mitochondrial genome was 100X. The nucleotide composition of the mitochondrial genome was 33.4% A, 39.1% T, 11.0% C and 16.5% G. Phylogenetic analyses showed that Cambaroides dauricus has a very close relationship with Cambaroides wladiwostokiensis. The results of 5S rDNA showed that the genetic relationship between Procambarus clarkii and Cambaroides dauricus is quite close. After determining the nutritional components of Cambaroides dauricus’ muscles with normal analysis methods, the results revealed that it has a crude protein content of 18.47 ± 0.87 per 100 milligrams, a crude fat content of 0.83 ± 0.12 per 100 milligrams, a crude ash content of 0.63 ± 0.06 per 100 milligrams and a moisture content of 79.8 ± 0.72 per 100 milligrams. There are eight essential amino acids in its protein, accounting for 41.59% of the total amino acids, and the proportion of umami amino acids is 36.27%. This study will provide a valuable basis for further studies of taxonomy, phylogenetic analyses and artificial breeding in Cambaroides dauricus. Full article

The Maghreb region of North Africa, located at the intersection of the Palaearctic and Afrotropical zones, is a biodiversity hotspot for terrestrial and freshwater taxa, including the freshwater crab of genus Potamon Savigny, 1816. Recent molecular studies have suggested the presence of two distinct Potamon species in the region: Potamon algeriense Bott, 1967, and an as-yet undescribed taxon, Potamon sp. However, comprehensive data on their distribution, genetic structure, and conservation status are still lacking. In the present study, we integrate new field collections from Algeria and Morocco (2021–2023) with molecular analyses of mitochondrial (COI, ND1) and nuclear (28S rDNA) markers to assess species boundaries and genetic diversity within Potamon across the Maghreb. Phylogenetic reconstructions based on Maximum Likelihood and Bayesian Inference consistently support the presence of two well-differentiated Potamon lineages in the region, corresponding to P. algeriense in western and central Maghreb, and Potamon sp. in eastern Algeria and Tunisia. While Potamon sp. exhibits low intra-specific genetic variation, P. algeriense displays a deeply structured mitochondrial lineage composition, forming four geographically coherent subclades, each corresponding to distinct hydrological regions. In light of this, it would be advisable to revise the IUCN assessment to include both species and updated information on their distribution. Full article

Seven new species of the genus Cherax from the western region of Western New Guinea, Indonesia, are described and illustrated. All new species—Cherax veritas n. sp. from the southeastern part of Misool Island of Raja Ampat Regency, Southwest Papua; Cherax arguni n. sp. and Cherax kaimana n. sp. from the northern part of Kaimana Regency, West Papua; Cherax nigli n. sp. from the southeastern part of Kaimana Regency, West Papua; Cherax bomberai n. sp. from the northeastern part of the Fakfak Regency, West Papua; Cherax farhadii n. sp. and Cherax doberai n. sp. from the Teluk Bintuni Regency, West Papua—belong to the northern group of Cherax. The new species are compared with their closest relatives, from which they can all be easily distinguished by morphological characters, such as the shape of the chelae, rostrum, body, and by their coloration. A molecular phylogeny based on a mitochondrial gene fragment, 16S, supports the morphology-based description of the seven new species, which can also be clearly distinguished by sequence differences. Full article

Feeding habits of the four-spotted megrim, Lepidorhombus boscii, from the eastern Adriatic Sea were examined. A total of 1070 individuals collected using a bottom trawl net between July 2020 and June 2021 were analyzed. A high percentage of empty stomachs (63.27%) was recorded. The food composition proved that L. boscii is a carnivorous species. The identified prey of L. boscii was divided into seven groups: Teleostei, Bivalvia, Gastropoda, Cephalopoda, Isopoda, Mysida, and Decapoda. Decapods were the most important prey (%IRI = 58.18), followed by cephalopods (%IRI = 10.93). At the species level, the most important prey were the decapods Parapeneus longirostris (%IRI = 11.48) and Goneplax rhomboides (%IRI = 5.92). Statistically significant seasonal variations in diet were recorded; decapods dominated in spring, summer, and winter, whereas cephalopods prevailed in autumn. There were no statistically significant differences in the food composition between the three size categories. Decapods were the most important prey in all size categories (%IRI > 50). The lowest feeding intensity, as well as the highest percentage of empty stomachs, was recorded in winter, which is also the main spawning season of this species in the Adriatic Sea. Full article

The taxonomy of the genus Metopograpsus is still a matter of debate because its species have limited morphological differences. Mitochondrial genomes, which are highly informative and easily accessible genetic markers, have been widely used to study molecular evolution and clarify relationships among species. This study aims to investigate the mitochondrial genome of Metopograpsus quadridentatus, a species with unique ecological and evolutionary significance. By analyzing the mitochondrial genome, we seek to address taxonomic uncertainties and provide insights into the evolutionary history of this species. In this study, we sequenced and analyzed the mitochondrial genome of M. quadridentatus to investigate its gene rearrangement patterns and its place within Brachyura. We compared the gene order of M. quadridentatus with that of 40 other Brachyuran species and created phylogenetic trees based on the nucleotide and amino acid sequences of 13 protein-coding genes (PCGs). We found that the mitochondrial gene arrangement of M. quadridentatus is mostly unchanged, similar to the original crustacean pattern, except for the movement of the trnH gene. Notably, the gene orders of several families, such as Eriphiidae, Grapsidae, Camptandriidae, Dotillidae, Plagusiidae, Ocypodidae, and Gecarcinidae, are the same. Phylogenetic analyses consistently placed M. quadridentatus within the genus Metopograpsus and the family Grapsidae, confirming its current taxonomic classification. These results offer important insights into evolutionary relationships and gene order conservation within Brachyura. Our study highlights the significance of mitochondrial genomes in resolving taxonomic uncertainties within the genus Metopograpsus. Full article

Background/Objectives: Freshwater shrimps of the family Atyidae, particularly the hyperdiverse genus Caridina, are keystone decomposers in tropical aquatic ecosystems and valuable aquaculture resources. However, their evolutionary relationships remain unresolved due to conflicting morphological and molecular evidence. Here, we sequenced and characterized the complete mitochondrial genome of Caridina mariae (Tiger Shrimp), aiming to (1) elucidate its genomic architecture, and (2) reconstruct a robust phylogeny of Caridea using 155 decapod species to address long-standing taxonomic uncertainties. Methods: Muscle tissue from wild-caught C. mariae (voucher ID: KIZ-2023-001, Guangdong, China) was subjected to Illumina NovaSeq 6000 sequencing (150 bp paired-end). The mitogenome was assembled using MITObim v1.9, annotated via MITOS2, and validated by PCR. Phylogenetic analyses employed 13 protein-coding genes under Bayesian inference (MrBayes v3.2.7; 10⁶ generations, ESS > 200) and maximum likelihood (RAxML v8.2.12; 1000 bootstraps), with Harpiosquilla harpax as the outgroup. The best-fit substitution model (MtZoa + F + I + G4) was selected via jModelTest v2.1.10. Results: The 15,581 bp circular mitogenome encodes 37 genes (13 PCGs, 22 tRNAs, and 2 rRNAs) and an A + T-rich control region (86.7%). Notably, trnS1 lacks the dihydrouracil arm—a rare structural deviation in Decapoda. The 13 PCGs exhibit moderate nucleotide skew (AT = 0.030; GC = −0.214), while nad5, nad4, and nad6 show significant GC-skew. Phylogenomic analyses strongly support (PP = 1.0; BS = 95) a novel sister-group relationship between Halocaridinidae and Typhlatyinae, contradicting prior morphology-based classifications. The monophyly of Penaeoidea, Astacidea, and Caridea was confirmed, but Eryonoidea and Crangonoidea formed an unexpected clade. Conclusions: This study provides the first mitogenomic framework for C. mariae, revealing both conserved features (e.g., PCG content) and lineage-specific innovations (e.g., tRNA truncation). The resolved phylogeny challenges traditional Caridea classifications and highlights convergent adaptation in freshwater lineages. These findings offer molecular tools for the conservation prioritization of threatened Caridina species and underscore the utility of mitogenomics in decapod systematics. Full article

This study aims to elucidate the characteristics of the mitogenome of Lysmata lipkei and investigate its phylogenetic relationships. Using both the Illumina NovaSeq 6000 (Illumina, Inc., San Diego, CA, USA) and PacBio Sequel II (Pacific Biosciences of California, Inc., Menlo Park, CA, USA) platforms, the complete mitogenome sequence of L. lipkei was determined. The mitogenome of L. lipkei was annotated, measuring 17,497 bp in length and comprising 13 protein-coding genes (PCGs), 2 ribosomal RNA genes (rRNAs), and 22 transfer RNA genes (tRNAs). The nucleotide composition of the genome exhibited an AT bias of 63.4%. Among the PCGs, the most frequently used codon was UUA. All tRNAs, except for trnD, which lacks the TψC loop, were capable of forming the typical cloverleaf structure. Phylogenetic trees for Caridea were constructed using Bayesian Inference (BI) and Maximum Likelihood (ML) methods based on the nucleotide sequences of the 13 PCGs. Both methods yielded consistent topological structures, with L. lipkei showing the closest phylogenetic relationship to L. kuekenthali. Additionally, Lysmatidae, Thoridae, and Hippolytidae formed a monophyletic clade. This research not only filled the gap in mitogenome data for Lysmatidae but also provided novel molecular insights into Caridean phylogenetics. Full article

The habitat characteristics preferred by Penaeus shrimp inhabiting positive (freshwater-dominated) estuaries in North America have been scarcely investigated. Identifying the main environmental factors within the estuary that affect shrimp abundance is relevant to understanding habitat utilization within this particular nursery habitat. This study aimed to evaluate the distribution of penaeid shrimp species along the Soto La Marina River estuary (Northeastern Mexico), analyzing the influence of abiotic factors (water temperature, salinity, and dissolved oxygen) and submerged aquatic vegetation biomass on shrimp populations. A total of 1069 shrimp belonging to four penaeid species (Penaeus aztecus, P. duorarum, P. brasiliensis, and P. setiferus) were collected. Except for P. setiferus, the highest shrimp abundance was near the mouth of the estuary, where the highest salinity and seagrass biomass (Halodule wrightii) were recorded. Salinity and seagrass biomass were the main factors influencing penaeids’ spatial preferences along the estuary, showing significant positive relationships with shrimp abundance in most of the cases examined. Penaeus setiferus was the only species exhibiting peak abundance in an estuarine area devoid of aquatic vegetation (without seagrass or macroalgae) and with a significantly lower salinity level (ca. 22 ppt) than the levels recorded near the river mouth (ca. 28–32 ppt). Differences in osmotic capacity between the species, the protective function of seagrasses against currents, and their role as feeding and refuge habitats could explain the observed spatial distribution in the estuary. Full article

The palaemonid shrimp genus Pseudopalaemon Sollaud, 1911, is endemic to South America, comprising seven freshwater and low salinity species. This study aimed to compile an overview of the genus, including an illustrated identification key for species and updated distributional data. Diagnostic morphological characters of the species were analyzed using specimens from several museums and other scientific collections. Current knowledge about the genus reveals significant knowledge gaps, particularly in species ecology. The data and insights from this study support future research and highlight a need for further studies on this group. Full article

Freshwater shrimps of the family Atyidae of New Guinea, including those from the Indonesian province of Papua, the Aru Islands, and the country of Papua New Guinea, are reviewed. A taxonomic synopsis is given to the 35 species identified so far, including two new species, namely Caridina iriana and C. yapenensis. Six species are recorded for the first time from New Guinea, namely Caridina mertoni, C. neglecta, C. brevicarpalis, C. endehensis, C. appendiculata, and C. cf. sikipozo. Seven landlocked species are found to be endemic to New Guinea, namely C. demani, C. cognata, C. fecunda, C. rouxi, C. buergersi C. elisabethae, and Parisia holthuisi. Biogeographically, apart from 11 species endemic to New Guinea, the majority of the amphidromous atyid shrimp species are found to be either restricted to the Island Chain of West Pacific (8 species) or restricted to the Indo-Australian Archipelago region, with New Guinea/Solomon Islands being the eastern and India/Sri Lanka being the western limits of their ranges (8 species), and five are restricted to the West Pacific, with Sulawesi/Philippines their western limit. Only three species are widely distributed in the Indo-West Pacific region. Descriptions/diagnoses for the new, taxonomically important or poorly known species, taxonomic discussions, habitat and distribution information for all species are presented. Full article

Two new species of the genus Cherax are described and illustrated. Cherax rayko n. sp., endemic to the Bian River drainage basin in the Muting District, in the northern part of the Merauke Regency, South Papua, Indonesia, is described, figured, and compared with its closest relatives, Cherax alyciae, Lukhaup, Eprilurahman & von Rintelen, 2018, and Cherax peknyi Lukhaup & Herbert, 2008. The new species may be easily distinguished from both by the shape of the rostrum, the shape of the chelae, the shape of the scaphocerite, and the coloration. Cherax phing n. sp., endemic to the Kali Ombak River drainage basin in the western part of the Kepala Burung (Vogelkop) Peninsula, Southwest Papua, Indonesia, is described, figured, and compared with its closest relatives, Cherax pulcher Lukhaup, 2015a, Cherax boesemani Lukhaup & Pekny, 2008, Cherax wagenknechtae Lukhaup and Eprilurahman, 2022, and Cherax gherardii Patoka, Bláha & Kouba, 2015. The new species may be easily distinguished from the latter species by the shape of the chelae, rostrum, and body and by the coloration. A molecular phylogeny based on a mitochondrial gene fragment, 16S, supports the morphology-based description of the two new species, which can also be clearly distinguished by sequence differences. Full article

Leptochela Stimpson (1860) is a shallow-water, benthopelagic genus within the predominantly pelagic superfamily Pasiphaeoidea. We inventoried a global fauna of 17 currently valid species of Leptochela and identified a newly discovered eighteenth species. Our analysis combined both morphological and molecular data, using 13 characters (including two multistate characters) and 5 gene markers, respectively. The results revealed incongruence between the molecular and morphological datasets. However, our phylogenetic conclusions were based on a consensus approach, integrating morphological, molecular, and total evidence trees, which revealed three robust clades. We discuss the evolutionary development of quantitative and qualitative morphological traits in Leptochela and explore the potential causes of the incongruence between morphological and molecular signals, particularly in the context of pelagic eucarids transitioning from pelagic to benthopelagic habitats. Additionally, we describe the new species from Madagascar and provide a key to all known species of Leptochela. Full article

The best practice for killing decapod crustaceans lacking a centralized ganglion has been debated for a century. Currently, there is a movement away from live boiling towards electrocution and mechanical splitting or spiking, which are efficient in the large commercial setting but may be unavailable and impractical for small decapods such as shrimp and prawn in the small-scale setting of, e.g., the household. Here, using carcasses of varying sizes of prawn, crayfish, lobster and green and brown crab, we used micro-CT imaging to measure surface area and sphericity in relation to body mass. Then, we measured heating profiles at the anterior ganglion and in the core of carcasses of the same species when exposed to standardized boiling regimes. We found a relationship with positive allometry between surface area and body mass for all species and a decrease in sphericity with mass. Heating times until proposed stunning (26 °C) and killing (44 °C) varied with body size and starting temperature and exceeded minutes for larger species. For a small species like prawn, times to stunning and killing by boiling are comparable to electrocution times and within the acceptable range compared to recreational killing of other sentient beings such as game mammals. Full article