Invertebrate Survival Journal

Influence of sex on intestinal microbiota of Pacific white shrimp Penaeus vannamei

G-Z Wang — 2025-07-21

Penaeus vannamei is a high-value aquaculture species. However, with the expansion in farming area and the rise in stocking density, the disease problems of P. vannamei have grown increasingly severe. Given the pivotal role of intestinal microbiota in regulating host health, including digestion, immune function, and metabolic homeostasis, understanding microbial dynamics is critical for disease control. Notably, although pronounced sexual dimorphism exists in P. vannamei, gender-specific microbiota variations remain uncharacterized. This study intends to evaluate the impact of gender variations on the intestinal microbiota of P. vannamei, using the 2bRAD-M technique. The results showed that the average growth rate of female shrimp was significantly higher than that of male shrimp. The Chao 1 index and Simpson index of female shrimp were greater than those of male shrimp. β-diversity research suggested that the female group samples might contain more microbial variety. At the phylum level, the microbial composition of the female and male shrimp groups is similar, with Pseudomonadota, Bacillota_A, Bacteroidota, Actinomycetota, and Planctomycetota being the dominating phyla. At the species level, the female group is predominantly formed of Phaeobacter italicus, NSJ_50_sp014385105, Pseudoalteromonas spongiae, and Xanthomarina gelatinilytica, while the male group contains a larger abundance of Vibrio parahaemolyticus and Vibrio cholerae. These data indicated that female P. vannamei not only display faster growth rates, but also possess a more complex and diverse intestinal microbiota, which may contribute to their higher disease resistance compared to male ones.

Transcriptome analysis of Apostichopus japonicus early in the regeneration process after evisceration

BC Wu — 2025-06-19

In extreme salt stress and anaerobic conditions, Apostichopus japonicus survives by "evisceration." The species can eject its viscera and create a new organ if the habitat is suitable. The molecular response of A. japonicus coelomocytes and visceral regeneration is examined. Previous research found A. japonicus coelomocyte volume recovery 2 h-p-e (two hours post-evisceration) mirrored fast human hematopoiesis. Coelomocytes returned to pre-evisceration levels 6 h-p-e (six hours post-evisceration). First, KCL solution was artificially injected at A. japonicus body mass. Subsequently, evisceration occurred. Immunological tissue coelomocytes were taken at 2 h and 6 h-p-e, and those from the control group (0 h) were also collected. Coelomocyte transcriptome was sequenced. Transcriptome sequencing was applied to the collected coelomocytes. At 2 h-p-e, 860 differentially expressed genes were identified, with 639 upregulated and 221 downregulated. At 6 h-p-e, 1638 genes were upregulated and 432 downregulated. Immunity genes were predominantly differentially expressed in the ‘Molecular function’ category, the major category for these immunity - related differentially expressed genes. Gene differences were analyzed using KEGG annotation. At 2 h-p-e, by comparing the gene expression of A. japonicus coelomocytes with that of the non - eviscerated control group (0h), 860 DEGs were identified. These DEGs were associated with 53 pathways, 22 of which were related to illnesses and the immune system, like the ECM - receptor interaction pathway. 6 h-p-e, 20 major enrichment routes were selected, and 11 of them, including the Phagosome pathway, were associated with regeneration. [Abstract cut for lenght]

Toxicity of the two insect growth regulators, pyriproxyfen and Lufox® against cotton bollworm

M Khorshidi — 2025-02-25

This study investigated the field effects of two insect growth regulators, pyriproxyfen and lufenuron+fenoxycarb (A commercial combination), on some biological and physiological characteristics of third instar larvae of the cotton bollworm, Helicoverpa armigera Hubner. The insecticides significantly affected the weight and duration of larval and pupal development, the longevity of males and females, the egg laying and hatching rates. The larvae treated with sublethal concentrations showed an increase in the total number of hemocytes, plasmatocytes and granulocytes. A significant increase in aminotransferase activity was also observed in the hemolymph of treated larvae. The increased activity of acid phosphatase and alkaline phosphatase was also observed in the treated H. armigera larvae. The total activity of esterase and glutathione S-transferase as detoxifying enzymes also increased significantly after pyriproxyfen and lufenuron+fenoxycarb treatments compared to control. In contrast, the amount of storage macromolecules, protein, triglycerides and glycogen, which are related to the energy cost of pesticide treatment, decreased in the treated larvae compared to the control. According to the results of the present research, the pesticides pyriproxyfen and lufox can be used to control the population of H. armigera by interfering with the intermediate metabolism and cellular immunity of the larvae, but their efficiency and compatibility should be considered with other control methods, especially biological factors.

XXV scientific meeting of the Italian Association of Developmental and Comparative Immunology (IADCI), February 19-21, 2025, Department of Sciences and Technological Innovation - DISIT, University of Eastern Piedmont “Amedeo Avogadro”, Alessandria, Italy

F Dondero — 2025-06-19