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 The changes of biodiversity, indicator species (IS) and catch per unit effort (CPUE) of bony fishes in beach seines in Iranian waters of the Caspian Sea during 1996 to 2012 was investigated. Among the catch of 14 species/groups, kutum and mullet comprised 56.78% and 31.81% of the total catch. Minimum and maximum CPUE were 158.5±9.1 and 344.9±31.2 kg/haul and Shannon diversity was 0.57±0.02 and 0.92±0.02, respectively. There were significant differences in community composition of fishes in beach seines among three seining times (morning, afternoon and night time), three seining periods (1996-2000, 2000-2005 and 2005-2012), three regions (west, middle and east), and different seasons (in all cases MRPP, p<0.001). During 1996-2000, Rutilus rutilus, Vimba vimba, Chalcalburnus chalcoides, Aspius aspius, Barbus sp., Salmo trutta caspius and, Silurus glanis in the years 2000-2005 species/groups shads, Abramis brama and Esox lucius and in the years 2005-2012 species Cyprinus carpio and Stizostedion lucioperca were indicator species. Also, in the west region of the Caspian Sea species/groups V. vimba, C. chalcoides, A. aspius, Barbus sp., A. brama,S.lucioperca,E.lucius and S. glanis; in middle Rutilus frisii kutum, shads and S. trutta caspius and in east species/groups mullets, R. rutilus and C. carpio were identified as indicator species.

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A systematic parasitological examination was carried out on 266 freshwater fish speci-mens, belonging to 11 species, from Northwest of Iran during the period from Summer 2001 to Summer 2002. Twelve parasite species including Diplostomum spathaceum, Al-locreadium isoporum, Ligula intestinalis, Digrama sp., Caryophylleus laticeps, Rhabdocona hellichi, Eustrongylides excisus, Argulus foliaceus, Lamprolegna compacta, Myxobolus musayevi, M. cristatus, and Neoechinorhynchus rutili were isolated and identified. It was concluded that Sander lucioperca, Albornoides bipunctatus, Capoeta capoeta, Carassius carassius and Barbus capito were five new hosts for those parasites in Iranian freshwater fishes. Furthermore, Myxobolus cristatus is recorded for the first time among Iranian freshwater fishes. All the parasites were collected from natural waters, but these rivers form a very important water reservoir in this area and these parasites can injure cultured fishes under certain conditions.

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Aims: Monitoring of the fish biomass is one of the basic principal of fisheries management, but ornamental and reef fish stocks, because of difficulty of estimating their abundance, have been less studied than others. The aim of this study was to estimate the standing biomass of ornamental and reef fishes in Larak Island, in the Strait of Hormuz.
Materials &Methods: Standing biomass of the fish species was assessed seasonally using Underwater Visual Census Method (UVCm) in coral reefs and  mesophotic coral reefs in Larak Island throughout 2018 and 2019. Two popular methods in UVCm (belt transect and stationary point) were used based on topography of sea bottom. The confidence interval of estimated standing biomass is calculated using bootstrapping method.
Findings: The standing biomass of ornamental and reef fishes is estimated as 2522.18, 5222.17 and 1325.15(Kg.) in Site 1, Site 2 and Site 3, that are located in 3-15meters depth. The standing biomass at Site 4, was estimated as 884.13kg. The minimum were observed in summer, also the result showed  that the standing biomass in summer was significantly lower than other seasons (P <0.05). In addition, the temporal diagnostic test showed that population structure of fish in the spring, autumn, and winter seasons was similar but significantly different from the population structure in summer.
Conclusion: The less of standing biomass in summer season can be affected  by seasonal migrations of fish in tropical and subtropical waters to deeper waters, in order to trade of the stresses caused by temperature fluctuations.
 

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This paper presents a total of 11 known crustacean parasite species from 51 host species belonging to 7 families, with 17 genera reported from cultured and wild fishes in three faunal regions of Iran. Among them, one belonging to Branchiura order, namely Argulus foliaceus, was found on Capoeta capoeta in Makoo Reservoir as well as on Cyprinus carpio, Chalcalburnus sp., Hypophthalmichthys molitrix and Mastacembelus mastacembelus in Zarivar Lake. The other 10 species belonging to Copepoda order include 1) Ergasilus sie-boldi, found on the gills of 2) Barbus sharpeyi, B. luteus, Aspius vorax and Cyprinus carpio; 3) E. peregrinus on Ctenopharyngodon idella and Leuciscus cephalus in Khandaqloo Res-ervoir; 4) Lamproglena compacta and 5) L. polchella on the gills of infected fish species in-habiting Tigris, Caspian and Oriental Regions of Iran. 6) Tracheliastes longicollis on the fins of Capoeta capoeta and Leuciscus cephalus; 7) T. polycolpus on the fins of Capoeta trutta, C. capoeta and Leuciscus cephalus in water bodies situated in Azerbaijan Province (Caspian Region) and Kurdistan Province (Tigris Region), 8) Achtheres percarum on the skin and fins of Sander lucioperca and Perca fluviatilis in Anzali Lagoon and Sefid-rud River in North of Iran (Caspian Region); 9) Pseudotracheliastes stellatus on the skin of acipenserids in Caspian Sea and finally 10) the most economically significant parasite, Lernaea cyprinacea, which is commonly found on cultured cyprinids in ponds and natural water bodies. Furthermore, several unknown crustacean species belong to both orders identified to genus level, which need further study for a detailed description. Geographi-cal distribution as well as host ranges of the mentioned parasites are presented and dis-cussed.

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Estimation of coral fishes biomass is needed as a basic benchmark for assessing the ecological status and fishing potential of coral reefs. Different methods are used to sampling the biomass of these communities, that direct observation is one of the preferred methods with respect to the non-destructive advantage. The purpose of investigation was to estimation standing biomass of coral fishes by Underwater Visual Census method (UVCm) in Abu-Musa Island seasonally from October 2019 to September 2020. also confidence interval was calculated of these estimations from the bootstrapping test (95%). Standing biomass of Coral fish and their confidence interval (95%) by bootstrapping simulation (n=479) were determinated 2923.6 kg., 4576.2 kg, and 1645.4 kg for the stations one, two and three respectively. The difference in the biomass standing of coral fish in three station could be related to the lack of differences in the amount of developed reefs, coral communities and significant differences in habitat availability.  Also, the standing biomass of coral fishes in the Abu-Musa Island are limited, that can be attributed to their low habitat, shortage of carrying capacity and the short life of the Persian Gulf basin, and stress that occurs in the ecosystem, especially bleaching events, that need more study in the future.

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