查看更多>>摘要：The sex determination and differentiation process of economically important crustaceans have been regarded as the focus of aquaculture for a long time, because of the sex-related weight dif-ferences. Neocaridina denticulata sinensis makes a suitable animal model for studying crustaceans because it can reproduce many times under artificial control and has a short reproductive cycle. Male and female sex characteristics of the adult rice shrimp Neocaridina d. sinensis are morphologically obvious, but not in embryos and juvenile stages. At present, sex-specific DNA markers have not yet been developed. To produce a reliable molecular marker for sex in Neocaridina and to investigate molecular sex differentiation, we therefore focused on identifying sex-specific transcriptomic dif-ferences. In this study, we found three sex-specific expression genes, NDM, Sushi, and NDF, after screening a large number of transcriptome data. NDM and Sushi are male-specific expression genes, and NDF is a female-specific expression gene. Semi-quantitative RT-PCR analysis showed that NDM and NDF can act as molecular markers for the sex identification of Neocaridina in different develop-mental stages, especially sex identification for embryos and juveniles with the same morphological characteristics. However, Sushi can only act as a molecular marker for the sex identification of Neo-caridina in adult stages. Furthermore, in situ hybridization showed that a strong positive signal of NDM was detected in the male testis. At the same time, we explored the relationship between these three genes and sex differentiation. The results of RNA interference treatment show that knockdown of nd-IAG (Neocaridina denticulata sinensis insulin-like androgenic gland hormone) can change the expression of NDM and NDF. On the basis of the expression of the male-specific gene NDM and the female-specific gene NDF, we developed a molecular test that for the first time allows the unambigu-ous sex determination of Neocaridina samples lacking external sex-specific features from juvenile stages onward.
查看更多>>摘要：This study aimed to characterize and determine the distribution of proteases in various anatomical parts of Penaeus monodon using mainly electrophoresis on sodium dodecyl sulfate (SDS) polyacry-lamide gels impregnated with casein (casein-SDS-PAGE) and specific protease inhibitors. Twelve caseinolytic bands designated A-L, with estimated molecular masses of 11.4-49.6 kDa were detected by SDS-PAGE, and were most abundant in the hepatopancreas. Among the 12 bands, E, J, K and L were predominant, A, G and H were identified as chymotrypsin-like proteases, D, E, I, J, K and L were identified as trypsin-like proteases, and B, C and F were identified as serine proteases. The proteases were most active at 50 degrees C and pH 7.0. The proteolytic and trypsin-like activities of Penaeus monodon were most abundant in hepatopancreas extracts and least abundant in extracts from the haemolymph. Trypsin-like proteases in the hepatopancreas extract were found to activate prophe-noloxidase (proPO) to form phenoloxidase (PO).
Younis, Mai L.Mona, Mahy M.Rizk, El-Sayed T.Atlam, Aalaa I....
16页
查看更多>>摘要：Accumulation of heavy metals in tissues of the crayfish Procambarus clarkii and in water were evaluated in areas located in the Egyptian Delta (Gharbiya, Kafr El-Shaikh, and Menofiya) in 2010 and 2021. Statistics showed that in 2010 the highest concentration of heavy metals in the digestive gland and in muscles was Zn, both in Gharbiya and Menofiya, while Fe was the highest accumulated in the digestive gland, and Pb was the highest in muscles of samples from Kafr El-Shaikh. The results showed that heavy metal loads decreased in Kafr El-Shaikh in 2021, whereas Fe increased significantly (p <= 0.05) in Gharbiya and Menofiya (41.44 +/- 2.32, 47.25 +/- 2.64 mu g/g). Accumulation of Cd and Zn in gills and muscles decreased in all areas from 2010 to 2021, while a significant increase (p <= 0.05) was shown in Fe and Cu in 2021. All heavy metals significantly decreased (p <= 0.05) in waters of the studied areas from 2010 to 2021.
Kerfouf, AhmedDe los Rios-Escalante, Patricio R.Esse, Carlos
11页
查看更多>>摘要：The deep-water rose shrimp, Parapenaeus longirostris (H. Lucas, 1846), is the most dominant shrimp species on the Algerian west coast. In that area, the diet of P. longirostris was studied between July 2020 and June 2021. This approach to the diet of the rose shrimp was based on analysis of the stomach contents and determination of the ingested prey. A seasonal sampling was carried out in the main fishing ports (Beni Saf, Bouzedjar, Oran and Mostaganem). The results obtained showed that the shrimp feed intensively in spring and increasingly less in winter and summer. Crustaceans, foraminiferans, polychaetes, and molluscs constituted the most frequent preys in the diet, with respective frequencies of 58.85, 55.95, 36.63 and 32.04%. Small microplancton and mesoplancton prey (radiolarians, copepods, and various larvae) were less important in the diet of P. longirostris. Fish and echinoderms constitute accidental prey, of which the frequency is less than 10%.
查看更多>>摘要：A new species of the demersal copepod genus Pseudodiaptomus is described from Sulawesi, Indonesia. This species is definitely assigned to the Nudus species group. Pseudodiaptomus kleini n. sp. is distinguishable in the female by the posterior corners of its Pdg5 with 3 spine-like processes, the symmetrical CR, the Ur1 without any processes, and the form of the P5; in the male by the Ur1 naked, and the form of the P5.
查看更多>>摘要：During a survey of the zooplankton community of a protected coastal system on the Caribbean coast of Mexico, several adult females and immature individuals of the usually benthic or epiphytic harpacticoid copepod genus Peltidium, were recovered; they were identified as the Bahamian species P. perturbatum Geddes, 1968. This species has not been recorded from other areas of the Northwestern Tropical Atlantic (NWTA) region after its original description. Based on the examination of the Mexican Caribbean material, a complementary description of this species is presented including new details of antennules, caudal rami, leg 1, and cuticular ornamentation by using SEM analysis. Its finding in the Mexican Caribbean represents the southernmost record of the genus in the Americas and the first record for the Mexican copepod fauna. A key to the known species of the genus in the NWTA is also provided.
查看更多>>摘要：Orbitacolax bispinus Izawa, 2021 is redescribed based on specimens of both sexes of the adult, copepodid V female, and copepodid IV sex undetermined, which were all recovered together with those of O. leptoscari (Yamaguti, 1953) from under the scales of Pseudolabrus sieboldi Mabuchi & Nakabo, 1997 (Pisces, Perciformes, Labridae) in Japan. Descriptions of the male and copepodid V female are the first time for the species.
Lee, MiyoungKim, SuhyunJang, In-KwonKim, Ji Seok...
17页
查看更多>>摘要：Photorhabdus insect-related PirAvp (where vp stands for Vibrio parahaemolyticus) and PirBvp of Vibrio parahaemolyticus were expressed in Escherichia coli, designated rPirAvp and rPirBvp, respectively, then tested on 4 crustaceans via immersion tests. PirBvp toxin was detected from 2 h after incubation and accumulated with bacterial growth. The culture filtrate of 15 nM PirBvp toxin caused 100% mortality of Litopenaeus vannamei within 4 days after immersion. Litopenaeus vannamei showed 100% mortality at 7 days after immersion in purified 4 nM rPirAvp, rPirBvp, or rPirAvp + rPirBvp mixture. The cumulative mortalities in the rPirAvp, rPirBvp or rPirAvp + rPirBvp mixture were 50, 83 and 100% in Macrobrachium rosenbergii after 12 days of immersion, 11, 77 and 100% in Palaemon paucidens after 10 days of immersion, and 36, 96 and 100% in Macrophthalmus japonicus after 6 days of immersion, respectively.
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