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.

Atlantic seabob shrimp as biomonitor of Cu and Zn near port activities: is it really a suitable choice?

The trace elements concentration in the muscle of the Atlantic seabob shrimp (Xiphopenaeus kroyeri) caught in coastal fishing highlighted copper (Cu) and zinc (Zn), both related to antifouling systems, as the main elements related to the intensity of port activities of southeast Brazil (~20—to 22ºS). The aim of this study is to analyze if the behavior of Cu and Zn in the muscle of this shrimp species is constant among different sampling sites, verifying if the species is suitable as biomonitor for these elements. The shrimps came from fisheries done in 2017 in Vitória, Anchieta, and Farol de São Tomé, southeast Brazil. After sampling, each individual was categorized for gender and maturity stage, measured, and weighted. Bulk muscle samples were freeze-dried for determination of Cu, Zn, and ratios of stable isotopes of carbon (δ13C) and nitrogen (δ15N). The data analysis verified if the concentration of Cu and Zn in male and female shrimps vary among maturity stages and sampling sites, and how the concentration of Cu and Zn is related to shrimps foraging area and/or trophic position. Both bioaccumulation and growth dilution occurred, but not in the same way for genders and sampling sites, with Cu showing more variability. Relationships between elements and shrimps foraging area and trophic position did not show a clear trend among the sampling sites. Regression models indicated moderate relationships, explaining 51% (Cu) and 60% (Zn) of the association with the foraging area in Anchieta, but up to 8% in Vitória and Farol de São Thomé. For the trophic position, the models explained 33% (Cu) and 34% (Zn) in Anchieta and up to 14% in Vitória and Farol de São Thomé. The results showed that the utilization of this shrimp species as biomonitor of marine coastal environments near port activities to monitoring the levels of Cu and Zn is not a suitable choice, at least in the spatial scale considered by this study.

Comparing size selectivity and exploitation pattern of diamond-mesh codends for Southern velvet shrimp (Metapenaeopsis palmensis) in shrimp trawl fishery of the South China Sea

In this study, size selectivity and exploitation pattern of six diamond-mesh codends with different mesh sizes, ranging from 25 to 54 mm, for Southern velvet shrimp (Metapenaeopsis palmensis) were tested and compared in a shrimp trawl fishery of the South China Sea (SCS). We used a codend with a mesh size of 25 mm (D25) as a starting point, which is the minimum mesh size (MMS) currently regulated in the studied area. Four different fishing population scenarios were applied to quantify and compare how mesh sizes of codends used would impact the size selectivity and exploitation pattern for the target shrimp species. The results demonstrated that the D25 codend was not proper for protecting juvenile shrimp at the studied area. By applying this legal codend, L50 (50% retention length) of the target shrimp species was below its minimum conservation reference size (MCRS, 7.0 cm total length), the retention probability of shrimp with a length of MCRS was above 95% CI [91–99] and more than 43% of undersized shrimp was retained. To mitigate the bycatch issue of undersized shrimp, increasing the mesh size in the diamond mesh codend is a simple and effective option. However, the loss of catch efficiency for marketable shrimp is a major concern while increasing the mesh size. A good compromise between releasing undersized shrimp and maintaining the legal individuals is manifested by using the codend with 35 mm mesh size (D35). Our study will be beneficial for the management of shrimp trawl fisheries in the SCS.

Isolation and genomic amplification of fish and shrimps from mangrove ecosystems in North Sumatra

Mangrove is a very typical ecosystem with a high level of diversity of flora and fauna. However, mangrove ecosystems are also one of the most vulnerable locations to extinction due to the high disturbances that occur. Some of the species that are susceptible to such disturbances are fish and shrimp. The use of barcode DNA is considered a fairly effective way to evaluate the condition of fish and shrimp populations in North Sumatra. Therefore, this study aims to obtain information on the success of kit methods and amplification patterns of barcoding marks 16S for fish and shrimp in mangrove ecosystems North Sumatra. The results showed that the kit extraction method produced a pattern of band that varied thick, thin and even smear. PCR amplification results with the 16S gene showed a good band pattern and indicated that the 16S primer used can detect fish and shrimp species that are visualized in the form of DNA bands.

Benefit-Risk Assessment of Fish And Shrimp Consumption From A Large Eutrophic Freshwater Lake, Southeastern China

Obtaining beneficial nutrients meanwhile ingesting hazardous contaminants through freshwater fish consumption remains a concern for inland residents in China. In this study, contents of fatty acids, essential trace elements (Fe, I, Zn, Se, Cu, Mo, Cr) and non-essential trace elements (As, Cd, Hg, Ni, Pb) were quantified in nine fish and two shrimp species from large eutrophic Chaohu Lake, southeastern China. Benefit-risk assessment for fish and shrimp consumption was conducted on basis of nutrients and contaminants. Total fat acids in the samples were 104.2-2405.2 mg/100g, included which DHA+EPA were 29.0-238.6 mg/100g. Mean content of essential trace elements (μg/g) in fish and shrimp species followed the order of Fe (10.3)>Cu (9.9)>Zn (7.7)> >Cr (1.42)>Se (0.337)>Mo (0.285)>I (0.023). The As, Cd, Hg, Ni, Pb content in the samples were nd-218, 14-97, 3-47, 4200-11300 and 144-1127 μg/kg, respectively, which was below the national maximum limit with the exception of Pb content in several samples. Though no obvious bioaccumulation pattern was found among species, species living in the demersal layers or with higher trophic levels tend to accumulate more trace elements. To achieve the recommended 250 mg of DHA+EPA daily intake, results of benefit-risk assessment indicated that fish and shrimp consumption can be major source of Se, Cu, Mo and Cr intake, whereas fish consumption was potential non-carcinogenic risk exposure for Ni and microcystins. Benefit-risk assessment contributed to the identification of main benefits and hazards of freshwater fish and shrimp consumption for inland populations around the large eutrophic lake.

First record of ghost shrimp Corallianassa coutierei (Nobili, 1904) (Decapoda: Axiidea: Callichiridae) from Indian waters

A Callichiridae ghost shrimp species Corallianassa coutierei (Nobili, 1904) is recorded and described here for the first time from the Indian waters. Formerly, five species under the family Callichiridae were recorded from different coastal waters of India. In addition, C. coutierei was infested with several copepods. Additional description of C. coutierei with key characters and distribution status is given for this species. A comprehensive checklist of the infraorder Axiidea is prepared based on previous records from Indian waters.

The Use of Chemical Cues by Sargassum Shrimps Latreutes fucorum and Leander tenuicornis in Establishing and Maintaining a Symbiosis with the Host Sargassum Algae

A mutualistic symbiosis exists between the alga Sargassum spp. and two shrimp species, Latreutes fucorum and Leander tenuicornis. However, little is known about how these shrimp locate and establish their host alga. Both visual and chemical cues are potentially available. A previous study has looked at both cue variables with results that are mixed. Specifically, these same shrimp species used chemical cues only when visible cues were available simultaneously. Visual cues would be presumably restricted at night, but chemical cues are potentially available continuously. This current research elaborates on the previous study to fully understand Sargassum shrimp chemoreception. Increases in sample sizes and both a 4-chambered and Y-maze apparatus were used to test whether the shrimp could detect Sargassum cues, dimethylsulfoniopropionate (DMSP) (a chemical excreted by some marine algae), and conspecific cues. Neither shrimp species showed a strong directional response to any of the chemical cues, but the Sargassum and DMSP cues did cause more shrimp to exhibit searching behavior. Additionally, several differences in responses between male and female shrimp were found for each cue. A lowered dilution of DMSP was also tested to determine sensitivity of L. fucorum shrimp to the chemical cue; although searching behavior was triggered, conclusions about quantifying the sensitivity could not be made. Overall, these results show the shrimp can detect chemical cues—in the absence of visual cues—that could affect initiating and maintaining this shrimp/algal symbiosis.

DNA barcoding and phylogenetic relationship of shrimps (Crustacea: Decapoda) of Bangladesh

We adopted DNA barcoding technique using a 658-bp fragment of the mitochondrial cytochrome c oxidase I (COI) gene to identify shrimp species collected from the different areas of Bangladesh. A total of 24 sequences were generated belonging to 14 species including four new records- Macrobrachium nipponense, Macrobrachium kistnense, Exopalaemon carinicauda and Alpheus malleator. Genetic distance measured with Kimura 2 parameter showed that genetic divergence increased with higher taxonomic rank. The mean genetic divergence was evaluated and found to be 0.935%, 22.67% and 30.92% within species, genus and family, respectively. In addition to the barcode-based species identification system, phylogenetic relationships were established where individuals belonging to the same species were grouped under the same clade. Maximum likelihood (ML) was preferred as the statistical method and as expected, the phylogenetic tree complemented and ensured the conventional taxonomy. The present study evidently showed that DNA barcoding can be served as an effective tool to discriminate the shrimp species and this will enhance the understanding on evolution and conservation biology. Bioresearch Commu. 7(1): 941-946, 2021 (January)