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Rhadinorhynchus laterospinosus Amin, Heckmann & Ha, 2011 (Rhadinorhynchidae) was described from a single female collected from a trigger fish, Balistes sp. (Balistidae) from the northern Pacific coast of Vietnam in Halong Bay, Gulf of Tonkin. More recent collections of fishes in 2016 and 2017 revealed wider host and geographical distributions. We report this Acanthocephala from nine species of fish representing six families (including the original record from Balistes sp.) along the whole Pacific coast of Vietnam. The fish species are Alectis ciliaris (Carangidae), Auxis rochei (Scombridae), Auxis thazard (Scombridae), Leiognathus equulus (Leiognathidae), Lutjanus bitaeniatus (Lutjanidae), Megalaspis cordyla (Carangidae), Nuchequula flavaxilla (Leiognathidae), and Tylosurus sp. (Belonidae). We provide a complete description of males and females of R. laterospinosus, discuss its hook metal microanalysis using EDAX, and its micropores. Specimens of this species characteristically have lateral trunk spines bridging the anterior ring of spines with posterior field of ventral spines and a proboscis with 15–19 longitudinal alternating rows of 21–26 hooks each varying with host species. We demonstrate the effect of host species on the distribution and size of the trunk, proboscis, proboscis hooks, trunk spines, and reproductive structures. The molecular profile of this acanthocephalan, based on 18S rDNA and cox1 genes, groups with other Rhadinorhynchus species and further seems to confirm the paraphyly of the genus, which is discussed.

Bivalves have proved to be useful bioindicators for environmental pollution. In the 17 present study, mussels (Mytilus galloprovincials), cockles (Cerastoderma edule) and 18 razor shells (Solen marginatus) were collected in the Ebre Delta, an extensive area 19 devoted to rice farming and affected by pesticide pollution, from April to July, the 20 heaviest ricefield treatment period. Possible effects of pollution were assessed through 21 biochemical markers (carboxylesterase (CE), antioxidant and neurotoxicity-related 22 enzymes and lipid peroxidation levels). Data on environmental variables, bivalve 23 reproductive condition and presence of organic pollutants, marine phycotoxins, 24 pathogens or histopathological conditions in bivalve's tissues were also evaluated. 25 Although the bioaccumulated pesticides did not explain the patterns observed for 26 biochemical responses, the obtained results point to an effect of environmental pesticide 27 pollution on enzymatic markers, with a prominent contribution of CE to such changes.

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Fipronil is a phenylpyrazole insecticide widely used to control pests in agriculture even 29 though evidence of harmful side effects in non-target species has been reported. A 30 comprehensive study on the effects of dietary administration of Regent®800WG (80% 31 fipronil) in European sea bass juveniles was carried out under two temperature regimes: 32 a) natural conditions, and b) 3 ºC above the natural temperature (an increase predicted 33 for the NW Mediterranean by the end of this century). Fipronil was added to the fish 34 food (10 mg fipronil /Kg feed) and the effects were studied at several time points 35 including right before administration, 7 and 14 days after daily fipronil feed and one-36 week after the insecticide withdrawal from the diet (depuration period). A wide array of 37 physiological and metabolic biomarkers including feeding rate, general condition 38 indices, plasma and epidermal mucus metabolites, immune response, osmoregulation, 39 detoxification and oxidative-stress markers and digestive enzymes were assessed. 40 General linear models and principal component analyses indicated that regardless of 41 water temperature, fipronil resulted in a significant alteration of several of the above 42 listed biomarkers. Among them, glucose and lactate levels increased in plasma and 43 decreased in epidermal mucus as indicators of a stress response. Similarly, a depletion 44 in catalase activity and higher lipid peroxidation in liver of fipronil-exposed fish were 45 also indicative of an oxidative-stress condition. Fipronil induced a time dependent 46 inhibition of Cytochrome P450-related activities and an inhibition of phase II 47 glutathione-S-transferase. Moreover, fipronil administration was able to reduce the 48 hypo-osmoregulatory capability as shown by the increase of plasmatic osmolality and 49 altered several digestive enzymes including trypsin, lipase, alpha amylase and maltase. 50 Finally, analyses in bile and muscle confirmed the rapid clearance of fipronil but the 51 persistence of the metabolite fipronil-sulfone in bile even after the 7-day depuration 3 52 period. Altogether, the results reveal a notable impact of this compound on the 53 physiological condition of the European sea bass. The results should be considered in 54 future environmental risk assessment studies since fipronil could be hazardous to fish 55 species, particularly those inhabiting estuarine ecosystems exposed to the discharge of 56 agriculture runoffs where this pesticide is mainly used.