Freshwater Shrimp Species Research Articles

Description of a new species of freshwater shrimp (Decapoda: Caridea: Atyidae) from Mount Danxia, Guangdong, China, based on morphological and molecular evidence.

A new atyid species, Caridina danxiaensis sp. nov., is discovered from Danxia Mountain National Nature Reserve in Guangdong Province. Morphological investigations show obvious differences from any known Caridina species. It can be easily distinguished from its congeners based on distinct characteristics of the rostrum, stylocerite, and uropodal diaeresis. Genetic analysis of Caridina based on 16S rRNA gene sequences also supports the distinctiveness of the new species from all other morphologically similar species. The sequence divergence (Kimura 2-parameter model) based on this gene between the new species and its closest congener, C. clinata, was 5.7%.

Caridina ngankeeae sp. nov., a new species of freshwater shrimp (Decapoda: Caridea: Atyidae) from Hong Kong.

A new species of freshwater atyid shrimp, Caridina ngankeeae sp. nov., is described from Hong Kong, southern China. The dorsally armed rostrum, the large number of spiniform setae on the uropodal diaeresis, the relatively long stylocerite and the distally deeply excavated pereiopod 1 carpus indicate a close relationship with the C. serrata Stimpson, 1860 species group and allied species primarily distributed in southern China and northern to central Vietnam. The new species can be distinguished from congeners by characteristics of the rostrum, pereiopods, and male first and second pleopods.

Histological analysis of Macrobrachium rosenbergii (de Man) eggs incubated in different salinities

Macrobrachium rosenbergii is the freshwater shrimp species of greatest economic interest, and its reproduction has been studied for commercial purposes. This study aimed to evaluate the effect of different salinities (0, 6, and 12 mg L-1) on the embryogenesis of this species. The females were observed daily according to their reproductive behavior. Upon the first sign of spawning, when their eggs were attached to the abdomen, they were collected for egg collection and transferred to the incubators at the respectively tested salinities. The eggs were collected every five days for up to 23 days, separated according to their stage of development, histologically processed, and stained for visualization of structural changes during embryogenesis using an optical microscope. From the egg's histological images at different embryonic development stages, the egg hatching time was evaluated, the changes that occurred in the eggs during embryogenesis, the total area of the eggs, the vacuole area, and the ratio between the vacuole area and the total area of the eggs. Differences were observed in hatching time, egg size, and vacuole area and area ratio. The 6 g L-1 of salinity treatment was statistically different from the other in all parameters analyzed. Therefore, it was concluded that 6 g L-1 of salinity positively influenced embryogenesis, as it presented hatches from the 15th day of embryogenesis, demonstrating that there was a greater speed of migration of vitellogenin for the formation of the embryo, accelerating embryogenesis and hatching of M. rosenbergii.

INVASI UDANG AIR TAWAR Macrobrachium lanchesteri DI DANAU BOLANO TOGA, TOLI-TOLI, SULAWESI TENGAH

Sulawesi Island has long been known as one of the regions in Indonesia that holds a wealth of freshwater shrimp species in both lentic and lotic waters. One of the lentic waters in Sulawesi is Lake Bolano Tago which is located in Toli-Toli Regency, Central Sulawesi. This research aims to reveal the population and abundance of freshwater shrimp in the lake. Sampling was carried out in April 2022 along the lake's littoral zone which was divided into 7 stations using purposive sampling and sweep methods. Sampling effort at each station was carried out for 4 hours. Environmental physicochemical factors measured include water temperature, brightness, dissolved oxygen levels, and water acidity levels. Specimen identification was carried out at the Animal Biosystematics and Evolution Laboratory, Biology Department, FMIPA, Tadulako University. Identification was carried out based on morphological characters by following the identification key of Wowor et al (2004). The results of this research revealed that of the freshwater shrimp collected as many as 1,165 individuals in the lake, all consisted of one species, namely Macrobrachium lanchesteri. This species belonging to the Palaemonidae family is not native to Indonesia but comes from the Oriental region. Macrobrachium lanchesteri was first described based on a type specimen originating from Thailand. Its presence in Lake Bolano Toga is quite worrying because of its invasive nature. With the abundant presence of the M. lanchesteri species at all stations, it can be confirmed that the Macrobrachium lanchesteri species has invaded Lake Bolano Toga

New record of Macrobrachium equidens shrimp (Dana, 1852) (Crustacea: Decapoda: ‎Palamonidae) as invasive species in Al- Mashaab River, East of Al- Hammar marsh, ‎Southern Iraq

A species of freshwater shrimp belonging to Macrobrachium Genus was recently recorded from Iraqi water. Morphological features accompanied by COI gene nucleotides sequencing identified that the shrimp species is Macrobrachum equidens, four forms of rostrum were observed. The total length of M. equidens recorded in this study was ranged from 40.38 - 55.33 mm for females and from 45.51 to 58.72 mm for males, while weight for females and males were 0.36 to 5.44g and 0.53 - 6.01 g respectively.

Effect of two diets on the fecundity of ablated and non-ablated female of Macrobrachium amazonicum

Macrobrachium amazonicum is a species of freshwater shrimp of great importance for aquaculture and to know its reproductive potential, through the study of its fertility is necessary. Therefore, this study aimed to evaluate the effect of two different diets on the reproductive performance of the species, whether or not adopting the ablation procedure. The experiment was carried out in a completely randomized design in a 2 x 2 factorial arrangement, with two types of feed (inert and fresh) and two conditions (ablated and non-ablated females), using six replicates per treatment. After 10 days of spawning, the eggs were removed and counted in their entirety. For each female, three spawns were obtained, totaling 72 samples. The fertility rate, the interval between spawning and the weight gain of the females were analyzed. There was no interaction between the studied factors, except for weight gain, in which ablated females that received fresh feed gained up to three times more weight than non-ablated females. Females that received fresh feed obtained higher fertility (1,373.9 eggs) than those that received only inert feed (1,084.1 eggs). The interval between spawns was 1.6 days shorter in ablated females.

A matter of size: Does habitat use depend on body size in Amazonian small-stream shrimp species?

ABSTRACT Natural selection is a key driver of organism size and shape, so resource use often depends on individual size. Among populations and assemblages there is overwhelming evidence that size- or stage-specific effects on niche occur mainly in habitat and food dimensions. A 2019 study by E. P. Silva and others, “Habitat segregation among freshwater shrimp species in an Amazonian rainforest stream system,” showed that Amazonian small-stream shrimp species show only slight habitat segregation at the scale of 50 m stream reaches, but that study did not take into account possible effects of intraspecific and interspecific differences in body size on habitat selection. We investigated through nighttime observations if conspecific shrimp of different sizes overlap in habitat use and whether heterospecific individuals of similar sizes differ in habitat use. Generalized linear mixed models were used to test possible relationships between body size and habitat features, and multivariate linear analysis and latent-variable model-based ordination were used to test for intraspecific and interspecific differences in habitat use. Mean frequency of use of habitat features differed among shrimp of different sizes and species, but use of habitat components strongly overlapped. Interspecific habitat overlap was greater among small individuals than large individuals. Our results indicate that size is not a major driver of habitat segregation in shrimp populations and assemblages, although it provides evidence of subtle ontogenetic shifts in habitat use by conspecifics of different sizes as well as differences between individuals of different species with similar sizes.

New insights into the regulation mechanism of red claw crayfish (Cherax quadricarinatus) hepatopancreas under air exposure using transcriptome analysis

Red claw crayfish (Cherax quadricarinatus) is an important freshwater shrimp species worldwide with enormous economic value. Waterless transportation is an inherent feature of red claw crayfish transportation. However, the high mortality of red claw crayfish is a severe problem in the aquaculture of crayfish after waterless transportation. In this study, we investigated the responses of the hepatopancreas from the red claw crayfish undergoing air exposure stress and normal conditions on transcriptome levels. We used Illumina-based RNA sequencing (RNA-Seq) to perform a transcriptome analysis from the hepatopancreas of red claw crayfish challenged by air exposure. An average of 57,148,800 clean reads per library was obtained, and 33,567 unigenes could be predicted and classified according to their homology with matches in the National Center for Biotechnology Information (NCBI) non-redundant protein sequences (Nr), Gene Ontology (GO), a manually annotated and reviewed protein sequence database (Swiss-Prot), protein families (Pfam), Clusters of Orthologous Groups (COG) of proteins, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. 690 and 3407 differentially expressed genes (DEGs) were identified between the two stress stages of the red claw crayfish. More DEGs were identified in 12 h, indicating that gene expressions were largely changed at 12 h. Some immune-related pathways and genes were identified according to KEGG and GO enrichment analysis. A total of 12 DEGs involved in immune response and trehalose mechanism were verified by quantitative real-time-polymerase chain reaction (qRT-PCR). The results indicated that the red claw crayfish might counteract the stress of air exposure at the transcriptomic level by increasing expression levels of antioxidant-, immune-, and trehalose metabolism-related genes. These transcriptome results from the hepatopancreas provide significant insights into the influence mechanism of air exposure to the trehalose mechanism and immune response in the red claw crayfish.

Exceptional preservation of internal organs in a new fossil species of freshwater shrimp (Caridea: Palaemonoidea) from the Eocene of Messel (Germany)

A new species of extinct freshwater shrimp was discovered in the Eocene deposit of the Messel Pit Konservat-Lagerstätte. This rare find is represented by only a few specimens, one of which showing exceptionally preserved soft tissues and other internal parts like the stomach with possibly gastric ossicles in place, branchiae, the ovary, and the left mandible, never described in a fossil shrimp. The new species Bechleja brevirostris n. sp. is characterized by a short rostrum bearing 6–8 dorsal spines and one ventral tooth, and long second pereiopods with strong chelae. One additional specimen shows a slightly different morphology and might belong to a different species. The systematic position of the species among the superfamily Palaemonoidea is discussed, as well as implications for the knowledge of the paleoenvironment of Lake Messel and the paleobiogeography of the Eocene.

Macrobrachium irwini sp. nov., a new species of freshwater shrimp from Western Ghats, India (Caridea: Palaemonidae)

A new species of the freshwater shrimp of the genus Macrobrachium irwini sp. nov., is described from the Nandhini River near Kateel, Karnataka region of Western Ghats, India. 11 specimens of Macrobrachium irwini sp. nov. were collected from Nandhini river running through a secondary forest with heavily vegetated banks. The morphological analyses revealed that the new species can be clearly distinguished from the closely related species, M. snpurii and M. scabriculum based on the shape and dentition on rostrum, antennular peduncle, segmental ratios of first pereiopod, tubercles along the cutting edges of immovable and movable fingers of second major pereiopod and telson. Additionally, we provided the striking colour patterns on the new species which could be distinguish this species from congeneric species.

Diversity, distribution and new records of freshwater and estuarine shrimp in the state of Amap, eastern Brazilian Amazon region.

This study presents the freshwater and estuarine shrimp species that occur in the state of Amap, in the eastern region of the Brazilian Amazon. The data were obtained through information contained in the Brazilian crustacean collections of the Institute of Scientific and Technological Research of the State of Amap (IEPA) and the National Institute for Research in the Amazon (INPA) and the detailed examination of the listed specimens. All information contained in the log book and specimen labels were noted for the identification and mapping of occurrence areas in the region. A survey in the literature of the species previously recorded for Amap was carried out. The diversity of freshwater and estuarine shrimp was composed of 21 species distributed in the following families: Alpheidae (Alpheus nuttingi), Euryrhynchidae (Euryrhynchus amazoniensis, Euryrhynchus burchelli, Euryrhynchus tomasi and Euryrhynchus wrzesniowskii), Lysmatidae (Exhippolysmata oplophoroides), Palaemonidae (Macrobrachium acanthurus, Macrobrachium amazonicum, Macrobrachium brasiliense, Macrobrachium carcinus, Macrobrachium jelskii, Macrobrachium inpa, Macrobrachium olfersii, Macrobrachium surinamicum, Nematopalemon schmitti, Palaemon carteri, Pseudopalaemon amazoniensis, Pseudopalaemon chryseus, Leander tenuicornis), Penaeidae (Xiphopenaeus kroyeri and Sergestidae) (Acetes marinus and Acetes paraguayensis). Alpheus nuttingi and L. tenuicornis were new records for the state of Amap. This study contributes to the knowledge of the diversity and geographic distribution of decapod crustaceans in Amap and highlights areas where there are gaps in collection, thus contributing to a better understanding of these invertebrates in the region.

A synopsis ofMacrobrachiumSpence Bate, 1868 (Decapoda: Caridea: Palaemonidae) from Hong Kong, with description of a new species

AbstractOnly four freshwater shrimp species from the genus MacrobrachiumSpence Bate, 1868 are known previously from Hong Kong, namely M. formosenseSpence Bate, 1868, M. hainanense (Parisi, 1919), M. meridionaleLiang & Yan, 1983, and M. nipponense (De Haan, 1849). This is likely an underestimate as a result of insufficient sampling, given that recent efforts revealed several new records in their counterpart family Atyidae, and the presence of many more Macrobrachium species from the region (i.e., Guangdong Province, China). We report the occurrence of three more species in Hong Kong: M. equidens (Dana, 1852), M. lar (Fabricius, 1798), M. venustum (Parisi, 1919), and a new species being described, M. lantausp. nov. The new species is erected from the highly variable M. equidens species complex, distinctive in live colouration and genetics. Decisive morphological differences from M. equidens sensu lato could not be confidently elucidated until the species complex is fully resolved. Molecular analysis shows that ‘M. hainanense’ reported from Hong Kong actually refers to M. laevisZheng, Chen & Guo, 2019. Morphological (and molecular) evidence suggest that M. inflatumLiang & Yan, 1985 and M. superbum (Heller, 1862) are possibly morphotypes and thus synonyms of M. nipponense. Macrobrachium hainanense and M. heterorhynchosGuo & He, 2008 are also likely synonyms of M. formosense and M. equidens, respectively. These species are, nevertheless, maintained as valid until examination of the type specimens concurs. The importance of an integrative approach and the associated matters needing attention in systematic studies of Macrobrachium are discussed.

Redescription of \(\textit{Caridina cucphuongensis Dang}\), 1980 (Crustacea: Decapoda: Atyidae) from Cuc Phuong National Park, Northern Vietnam

The freshwater shrimp species Caridina cucphuongensis (family Atyidae) was poorly described by Dang (1980). Moreover, the taxonomic status of this species is hard to verify as the types have been lost. This study provides a redescription of the species and designation of a neotype specimen. The Caridina cucphuongensis Dang, 1980 is characterized by short rostrum with large teeth on the dorsal margin, long stylocerite, subrectangular endopod of male first pleopod, and short appendix interna of the male second pleopod.

Species diversity of freshwater shrimp in Henan Province, China, based on morphological characters and COI mitochondrial gene.

Freshwater shrimp are a rich species group, with a long and problematic taxonomic history attributed to their wide distribution and similar morphological characteristics. Shrimp diversity and species identification are important cornerstones for fisheries management. However, identification based on morphological characteristics is a difficult task for a nonspecialist. Abundant freshwater shrimp species are distributed in the waters of Henan Province, but investigations of freshwater shrimp are limited in this region, especially concerning molecular features. Here, we combined morphology and DNA barcodes to reveal the species diversity of freshwater shrimp in Henan province. A total of 1,200 freshwater shrimp samples were collected from 46 sampling sites, and 222 samples were chosen for further microscopic examination and molecular delimitation. We used tree‐based methods (NJ, ML, and bPTP) and distance‐based methods (estimation of the paired genetic distances and ABGD) to delimit species. The results showed that there were nine morphospecies based on morphological characteristics; all could effectively be defined by molecular methods, among which bPTP and ABGD defined 13 and 8 MOTUs, respectively. The estimation of the paired genetic distances of K2P and the p‐distances had similar results. Mean K2P distances and p‐distances within species were both equal to 1.2%. The maximum intraspecific genetic distances of all species were less than 2%, with the exception of Palaemon modestus and M. maculatum. Various analyses have shown that P. modestus and M. maculatum have a large genetic differentiation, which may indicate the existence of cryptic species. By contrast, DNA barcoding could unambiguously discriminate 13 species and detect cryptic diversity. Our results demonstrate the high efficiency of DNA barcoding to delimit freshwater shrimp diversity and detect the presence of cryptic species.

Description of one new species of freshwater shrimp of the genus Caridina (Crustacea: Decapoda: Atyidae) from two karst caves of Northern Vietnam.

A new species of atyid freshwater shrimp is described from two caves of Bac Kan Province, Northeast Vietnam, namely Caridina namdat sp. nov. This species can be distinguished from its congeners by a suite of morphological characters such as reduced eyes with short eyestalk, very short and unarmed rostrum, slender second pereiopod, elongated endopod of male first pleopod, and long appendix interna of the male second pleopod. Molecular phylogenetic data from the mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA genes also support the distinctiveness of the new species from all other examined species.

Transcriptome analysis of five ovarian stages reveals gonad maturation in female Macrobrachium nipponense

BackgroundMacrobrachium nipponense is an economically important species of freshwater shrimp in China. Unlike other marine shrimps, the ovaries in adult female M. nipponense can mature rapidly and periodically during the reproductive period, but the resulting high stocking densities and environmental deterioration can negatively impact the harvest yield and economic benefits. To better understand ovary development in female M. nipponense, we performed systematic transcriptome sequencing of five different stages of ovarian maturation.ResultsWe obtained 255,966 Gb of high quality transcriptome data from 15 samples. Of the 105,082 unigenes that were selected, 30,878 were successfully annotated. From these unigenes, we identified 17 differentially expressed genes and identified three distinct gene expression patterns related to different biological processes. We found that cathepins, legumains, and cystatin were enriched in the lysosome pathway, and they are related to vitellogenin hydrolysis. Additionally, we found that myosin heavy chain 67 participated in oocyte excretion.ConclusionsWe provide the first detailed transcriptome data relating to the ovarian maturation cycle in M. nipponense. Our results provide important reference information about the genomics, molecular biology, physiology, and population genetics of M. nipponense and other crustaceans. It is conducive to further solve the problem of M. nipponense rapid ovarian maturation from the aspects of energy supply and cell division.

Cherry Shrimp Neocaridina davidi (Bouvier 1904) (Crustacea: Decopoda: Atyidae)

Neocaridina davidi is a species of freshwater ornamental shrimp that belongs to the Atyidae family. Neocaridina davidi originates from Taiwan, but their popularity in the aquarium trade has led to them being available in other countries. This shrimp has different common names based on its color. Wild type shrimp are generally transparent or brown in color, however, generations of selective breeding have produced a variety of colors and patterns.
 Also available on the Featured Creatures website at http://entnemdept.ufl.edu/creatures/MISC/cherry_shrimp.html

Deep into darkness: the first stygobitic species of freshwater shrimp of the genus Caridina (Crustacea: Decapoda: Atyidae) from Northern Vietnam.

The first stygobitic species of atyid freshwater shrimps from Vietnam is described from Cuc Phuong National Park, Northern Vietnam. Caridina thachlam sp. nov. can be distinguished from its congeners by a suite of morphological characters such as strongly reduced eyes without eyestalk, short and almost unarmed rostrum and slender pereiopods. Molecular phylogenetic data from the mitochondrial cytochrome oxidase subunit I (COI) and 16S ribosomal RNA genes also support the distinctiveness of the new species from all other species that we have examined.

Evaluation of the Degradation Level of a Fluvial Basin in the Western Area of Côte d'Ivoire: Case of the Cavally River

The present study is a diagnosis of the level of degradation of Cavally River in Cote d'Ivoire. Several abiotic indicators such as physico-chemical parameters were appreciated. These abiotic indicators were supported by biotic indicators sensitive to some variations in quality of water. That is the use of benthic macro-invertebrates as some species of freshwater shrimps of the genus Macrobrachium. Sampling was made between September 2015 and August 2016 on the upper course of Cavally River and the area on either side of the mining zone Ity. Measures of physico-chemical parameters such as dissolved oxygen, temperature of water, hydrogen potential, electrical conductivity, mercury rate and water transparency were made by season using multi parameters. Shrimps were caught monthly using dip nets and keep nets. The extreme value of physicochemical parameters is for dissolved oxygen value were 4.90 mg/l, temperature of water (25.55°C), hydrogen potential (8.48), electrical conductivity (53.14 μS/cm), mercury rate (5.75.10-3 mg/kg) and water transparency (27.06 cm). In general, the results showed that the extreme values of physico-chemical parameters were recorded in areas with high concentrations of anthropogenic activities. In the mining areas, high levels of mercury have been recorded above those of the WHO guideline for surface water. In total, M. vollenhovenii was the most abundant species with 383 individuals out of 879 specimens caught (43.57%). It is followed by M. dux with 321 individuals (36.51%) and M. macrobrachion with an abundance of 175 individuals (19.90%). Spatially, these species have been more abundant in the upstream and downstream areas which are more or less conserved environments. However, they were less abundant in mining areas. These results show that the upper course of the Cavally River is deteriorating. That constitutes a real threat to aquatic organisms and biodiversity.

Identification and characterization of a Toll-like receptor gene from Macrobrachium nipponense

Outbreaks of infectious disease in shrimp pose a serious threat to shrimp agriculture worldwide. Shrimp lack adaptive immunity and depend only on innate immunity as a defense system against infectious disease. Toll-like receptors (TLR) are reported to play a critical role in the innate immune system. In this study, we identified a Toll-like receptor gene of a species of freshwater shrimp, Macrobrachium nipponense, designated MnToll, for the first time. The sequence of MnToll encoded 935 residues arranged as 10 leucine-rich repeat (LRR) domains, a leucine-rich repeat C-terminal (LRR CT) domain and a Toll/interleukin-1 receptor (TIR) domain and displayed 90% amino acid similarity to previously identified TLRs (Toll 1 and 2) of Macrobrachium rosenbergii. We additionally evaluated mRNA expression of MnToll in various tissues, including heart, gills, stomach, digestive gland, ventral nerve cord, antennal gland and muscle. Following infection with a viral pathogen, white spot syndrome virus (WSSV), MnToll expression was significantly upregulated between 12 and 72 h. Our data collectively suggest that the newly identified MnToll gene belongs to the TLR family in shrimp and is potentially involved in innate host defense, especially against WSSV.