46 research outputs found
Morphometric and meristic characteristics of Vimba vimba persa in Sefidrud River
During years 1999-2001, a series of sampling was carried out in Sefidrud River to study morphometric and meristic characteristics of Caspian Vimba. 149 specimens were collected and then necessary measurements were considered and following results were obtained: T.L= 171.2±31.6mm, W= 62.9±19.7g, age= 3.49±0.9 year, average number of scales on lateral line = 50.83±1.8, branched ray of dorsal and anal fins = 7.96±0.2 and 17.58±1.0 respectively. The mean morphometric measurements with respect to body standard length (%) were: head length 24.47±1.9, eye diameter 6.10±1.07, body maximum depth 26.17±1.4, dorsal fin height and length 20.22±1.5 and 10.96±0.8, anal fin height and length 12.66±0.8 and 18.17±1.5, pectoral fin length 18.17±1.2, ventral fin length 14.97±1.1, pecto-ventral fins distance 24.18±l.7 and ventral-anal distance 20.00±1.5 and pre-dorsal distance 52.21±1.7. Adults and juveniles showed difference in 2 meristic and 15 morphometric parameters. On the other hand, the adult males and females showed difference in 16 morphometric parameters (esp. body depth, lengths of dorsal, pectoral, pelvic and anal fins). Also, adult males have a series of fine epithelial tubercles on head and body and their color is darker with more reddish anal and ventral fins
Studying natural reproduction, spawning grounds and spawning period of Vimba vimba persa population in Sefid-roud river, Guilan Province in north Iran
To evaluate spawning status of Vimba vimba ,population in Sefid-roud river, 621 breeders, 1136 larvae, fries and fingerlings were caught in the river using beach seine, cast-net and electro-choker over the years 1999-2000. We found that the fish started spawning migration in March and continued it until July with its peak occurring between mid-April to late-May. Fork length was 116 - 208 mm (153.1 ± 17.95) in male specimens and 122 - 222 mm (173.5 ± 1 6.46) in females. Total body weight ranged 21.1-116.1g (52.92 ± 19.23) in males and 23.1 - 170.0 g (77.90 ± 22.88) in females. Males aged 2-6 years (3.53±0.86) and females aged 3-7 years (4.19±0.92) participated in the spawning with their maturity age being calculated as 2 and 3 years respectively. In all, breeders were composed of 51.82% males and 48.18% females with the ratio being significantly different only in May. Gonad weight was 1.13-7.92 g (Avg. 2.89±0.29) in males and 3.21-25.47g (Avg. 10.40±1.52) in females. We found the highest gonad weight for the fish in June and that the gonad weight in female breeders increased upwards of the estuary. Gonado-somatic index was 19-21% in 85.7% of the females and 3-8% in 95.5% of the males. Spawning of the species took place during day and night from late May to late June with its peak in May in water temperature ranging 18-29 degrees centigrade on pebble and gravel pounds from 25 to 75kms away from estuary. The Disaam tributary was distinguished as the major spawning area for the species
Threatened fishes of the world: Paracobitis vignai Nalbant and Bianco, 1998 (Nemacheilidae)
Paracobitis vignai is a Nemacheilid loach endemic to the Sistan basin. It occurs in Helmand River and its related reservoirs in Sistan-va-Baluchistan Province in southeastern Iran and probably in Afghanistan. This species is currently endangered due to habitat loss or degradation, damming and droughts. Therefore, this paper reviews the available data on taxonomy and distribution of P. vignai, provides its morphometric features, and recommends actions for its conservation
Studying Caspian shad (Alosa caspia caspia) diet in southwest coastal area of the Caspian Sea, Guilan Province waters
Little is known about the biological characteristics of the Caspian shad, a commercial fish of Clupeidae family living in the Caspian Sea. Monthly random samples of the fish were collected at the Guilan province shores, southwest of the Caspian Sea from October 2001 to August 2003. Beach seine and gill nets were used in the sampling. Food items, condition factor and feeding changes with the change in the fish age, sex, station and season after invasion of زtenophore Mnemiopsis leidyi to the Caspian Sea were studied. Samples (n=262) had fork length 88-235 (156.7±31.9) mm, weighed 8-196 (51.92±32.7) grams and aged 1-6 (2.81±0.9) years old. The Vacuity Index (CV), Intestinal Relative Length (RLG) and Index of Fullness (IF) of the specimens were determined as 10.3%, 0.52±0.03 and 102.9±114.5, respectively. Phytoplankton (specially Rhizosolenia and Spirogyra) comprised 1.8%, zooplanktons (Ostracoda, Rhizopoda, Cladocera, Rotatoria, Copepoda, Cirripedia, Mysidacea, Bivalvia larvae and bony fishes larvae and eggs) comprised 98.0% and benthic fauna (Framinifera, Porifera, Cumacea, Amphipoda, insects larvae and Palaemonidae) comprised 0.2% of the food abundance in the fish stomach and intestine. Among the food items, orders Copepoda (Acartia spp.) and Cirripedia (Cypris balanus) were the main food, comprising 83.1 and 12.9% of abundance, respectively. Acartia comprised 97.3, 80.4, 48.0 and 68.3% of the food in autumn, winter, spring and summer, respectively. For Cypris balanus, these figures were 2.0, 2.6, 41.9 and 25.3% for the seasons. No significant difference was found in food diversity and its abundance between male and female fish and between different ages. Generally, Acartia spp. and Balanus were dominant food items in the male and female fish and in different sized specimens. Acartia comprised about 97.0% of the food abundance in Talesh and Kiashahr areas and 65.7% in Anzali shores. The zooplankton, as the main food item of the fish have suffered a major decrease due to the invasion of Mnemiopsis leidyi to the southern Caspian Sea. Hence, the index of fullness (IF) and growth of the fish shows a great reduction recently
Does length-weight equation fit clupeid fishes? An evaluation of LWRs for six clupeids from Iran (Teleostei: Clupeiformes)
This study investigates length–weight relationships of six clupeid species (Alosa braschnikowi, Alosa caspia, Dussumieria acuta, Nematalosa nasus, Sardinella albella and Tenualosa ilisha) captured from three main water bodies of Iran (Persian Gulf, Oman Sea and Caspian Sea), to evaluate if the LWR parameters fit for these fishes having specific morphological characteristics. Based on the obtained results, i) the b value was influenced by recorded length (TL, SL, FL) and body shape, ii) it was within the expected range of 2.27–3.48, iii) length–weight relationships were highly correlated and significant (r2>0.82-0.98, P<0.001), and hence length-weight equations fit well with six clupeid species in the Iranian water bodies. The results presented here, would be useful for fishery biologists and fisheries stake-holders in the study area
Some aspects of the life history of Oxynoemacheilus bergianus (Actinopterygii: Nemacheilidae) from the Jajrud River in the Namak Lake basin, Central Iran
The length-weight relationship, breeding season and condition factor of Oxynoemacheilus bergianus from Jajrud River in the Namak Lake basin, Tehran Province, Central Iran, were investigated. Sampling was performed from March 2017 to February 2018. The biometric measurements and the body and gonad weights were monthly carried out for one year log sampling occasions, in a total of 546 specimens. The range of total length in males and females were 3.8-7.5 and 3-7.6 cm, and the range of total weight were correspondingly 0.36-3.53 and 0.2-4.67 g respectively. The calculated coefficient of determination (r2) in males and females was found to be 0.94 and 0.95, respectively reflecting a positive allometric (b > 3, p > 0.05) growth in both sexes. The gonadosomatic index and modified gonadosomatic index showed that O. bergianus spawns in the middle of spring in May. In agreement with that, the condition factor reached the minimum (0.60) in February, while the maximum (0.96) in May. Since there is poor conservation status of the species, this study aims to give a contribution for biologists and wildlife managers
Chemical composition and antimicrobial activities of the essential oil from Myrtus communis leaves
Abstract: Nosocomial pathogens are associated with increased hospital stay lengths and mortality
rates. Increasing resistance to antibiotics makes the treatment of these infections more difficult. Novel
antimicrobial compounds derived from natural sources may be useful for addressing antiobiotic resistance.
The objective of this study is to determine the chemical composition and antimicrobial activities of essential
oils from Myrtus communis L. (Myrtaceae) leaves against pathogens causing nosocomial infections. The
chemical composition of essential oil from M. communis leaves was analysed by gas chromatography-mass
spectrometry (GC-MS). The antimicrobial activity of the essential oil against bacteria and fungi was evaluated
by broth micro-dilution as per the Clinical and Laboratory Standards Institute (CLSI) methods. GC-MS analysis
revealed that the major constituents of the essential oil were α-pinene (39.2 %), 1,8-cineole (22.0 %), and
linalool (18.4 %). The essential oil exhibited antimicrobial activity against all Gram positive and Gram negative
bacteria with MICs in the range of 0.5-32 μL/mL and 8-64 μL/mL, respectively. MICs for the tested
clinical and standard fungi were in the range of 0.03-16 μL/mL. The essential oil exhibited strong antibacterial
and antifungal activities against all the causative agents of nosocomial infections examined, particularly
against strains with antibiotic resistance. The essential oil from M. communis leaves is a potential source of
novel antimicrobial agents for the treatment of nosocomial infections
Studying distribution and biology of Neogobius caspius in Guilan province coasts (south Caspian Sea)
The Caspian goby, Neogobius caspius, is an endemic species of Gobiidae family in the Caspian Sea and it has ecological importance (as food for Caspian commercial fish such as sturgeons). The main aims of this study are, studying distribution, length, weight and age structure, sex ratio, diet, reproduction biology and morphological characters of this species in Guilan coast at waters of the Caspian sea and the sampling has been done monthly from Oct. 2005 to Sep. 2006 in 4 station from Astara to Chaboksar, with bottom trawl which had 12.5 meter length, 4.7 meter gape width and 2 mm mesh size in code end. The results showed N. caspius abundance is 9.82±11.93% of Gobiids and 7.92±10.10% of total fish numbers sampled in the study area (13824 specimens belong to 16 fish species) and there were significant differences among stations and seasons. CPUA of N.Caspius was estimated 52.5±105.9 ind/hec and 412.7±770.7 g/hec and there were significant differences among stations and seasons. Maximum body weight, total length and age were measured 65.10 g, 176 mm and 6 years old with an average 8.74±9.9 g, 84.83±28.4 mm and 1.83 years old, respectively and maximum age of males and females was 6 and 5 years old respectively and there were significant differences among stations and seasons and between sexes. It was estimated algometric growth model from length-weight regression, coefficient of K Von Bertalanffy growth model was estimated 0.42 and 0.68 in male and female, respectively. Sex ratio was 1.27 female to 1 male. Coefficient vacuity, relative gut length and intensity of 169 fullness were 8.72%, 0.76±0.17 and 267.7±263.3 for, respectively and Caspian goby fed on 30 different prey consist Zooplanktons (8 types), Benthic animals (15 types) and fishes (7 types) and young and yearlings have fed mainly mixed food (zooplankton and benthic animals) and adults on zoobenthose. Gammarids, Bivalvia, Cumaceae and Vormes constituted 44.7, 38.9, 24.8 and 19.7 % of prescence in full-gutted samples respectively, they were mainly preys (number and weight), hence this species is considered as euryphagus, carnivorous, benthphagus species. It was determined, Caspian goby spawns from March until last June, males and females take part in spawning in 2.8g and 65 mm and 1.3 g and 52 mm, respectively. Length at 50% maturity (LM50) was 80.2 and 77.5 mm in males and females, respectively. Maturity took place at 2 years old for both sexes, too. The absolute fecundity was estimated 109-1350 (451.6±216.3) eggs and relative fecundity 18-80 (36.8±9.2) eggs per one grams of body weight and diameter of ripe eggs was measured 1.31-2.60 (2.18±0.19) mm. Morphologically, there were 15 morphologically significant statistical differences between males and females and 15 differences among stations, sexual dimorphism was observed, too
Studying native fishes in Hamadan province
Studying native fishes of Hamadan province have been done in 159 stations from 51 important water resources (wetland, reservoir, spring, river and qanat) using with electric tool, cast-net, seine and gill-net gears from July 2010 to Oct. 2011 and the main aims were species identifying and determining their distribution and abundance in the studied area. In the study, 33411 fish specimens are caught in 257 times of sampling and selected randomly about 8500 individual and laboratory works showed the fish belong to 37 species from 7 families. Cyprinidae with 25, Nemacheilidae with 6 and Sisoridae with 2 species had the most diversity and Cobitidae, Poeciliidae, Salmonidae and Mastacembelidae had only a representative. 31 fish species were native or endemic and 6 species were alien. Fish species existed in all rivers of Ghezelozan and Sirvan sub-basins but there were not any fish in 10 rivers of Ghara-Chai sub-basin and in 6 rivers of Gamasiab sub-basin, too. Also, it was observe 1-3 fish species in 15 rivers, 4-6 fish species in 10 rivers, 7-10 fish species in 5 rivers and more than 10 fish species in 4 main water resources and Gamasiab sub-basin with 32 fish species was the most diversified and Ghezelozan sub-basin with 2 fish species was the least diversified. There were any species to 4 (mostly 1 or 2) fish species in studied qanats in Ghara-Chai and Gamasiab rivers sub-basins. 23 fish species existed in a subbasin, 12 species in 2 sub-basin, Capoeta capoeta in 3 sub-basin and Squalius cephalus in all sub-basins of studied area. Alburnoides nicolausi,Capoeta aculeata and Alburnus mossulensis have had the most frequency. Studying fish abundance showed Oxynoemacheilus argyrogramma with 17.8%, Garra rufa with 12.3%, A. mossulensis with 12.1% and C. aculeata with 10.2 % of total number of caught fish specimens are dominant. S. cephalus, Capoeta damascina, C. aculeata, C. trutta, Chondrostoma regium and A. mossulensis have had sport fishing value but Acanthobrama marmid, Oxynoemacheilus kiabii, Oxynoemacheilus kermanshahensis, Turcinoemacheilus kosswigi, Alburnus caeruleus and Mastacembelus mastacembelus have biodiversity value for being endemic or having limited habitats in Iran
Biological survey of Caspian kutum (Rutilus kutum) released fingerlings in Sefidroud River (Guilan Province)
Kutum fish (Rutilus kutum) is an anadromous cyprinid species that spawns in adjusted rivers to the Caspian Sea. Many million fingerlings were artificially produced and annually released in these rivers specifically in Sefidrud River by Iranian Fisheries Organization. In this study were estimated the staying period of Kutum fingerlings in Sefidrud River and its diet and growth. A small piece of the caudal fin was cut as a tagging method. About 50000 and 5200 individuals were marked during July and September 2013, respectively. The marked fish had an average total length 53.2±5.6 mm and body weight 1.11±0.26 g and were released in river around two kilometers of the estuary. The sampling of fishes had been earlier started from Feb. 2012 and continued until Feb. 2013 at five stations. Four stations were along river from three Kilometer of estuary to estuary and one station was in right side of estuary in the sea coast. The results showed that marked samples after releasing time were distributed in all studied area from 3 kilometers of estuary to estuary but they migrate mainly toward Caspian Sea in a short time. However the marked samples were observed in estuary and the sea coast after 6 and 24 hours of their releasing time, respectively, Kutum fingerlings remained in Sefidrud river ecosystem in a longer time, at least until end of our sampling period i.e. 105 days. The coefficient of vacuity index of the natural feeding study was 0.0, 49.0 and 30.6 % for phytoplankton, zooplankton and benthos, respectively. The average of GastroSomatic index, intensity of fullness and condition factor were calculated 6.30±3.25, 174.6±153.2 and 0.92±0.09, respectively. A temporal and spatial variation on main food items were observed in gut content of fish fingerlings from different locations and seasons. Gut contents were generally included 59 genera of phytoplankton, 15 groups of zooplankton and 10 groups of benthos. Nitzschia, Navicula and Synedra were dominated among phytoplankton genera with 45.83, 18.02 and 15.99 %, respectively. Among zooplankton groups; the Rotaria, Moeina and Difflugia were dominated with 22.30, 20.86 and 15.83%, respectively. Chironomidae and Gammaridae were the main food items among fed benthic animals with 83.67 and 11.15%, respectively. Furthermore 48 phytoplankton genera, 32 zooplankton genera and 6 benthic families were identified in ecosystem of Sefidrud river. Bacillariophyta phylum (with 23 genus), Rotatoria (with17 genus) and Chironomidae family were dominated in each mentioned groups, respectively. It is concluded that the Kutum fingerlings stay in Sefidrud River for a long time, although most of them migrate to Caspian Sea during first month after releasing. However dietary indices were normal in studied samples, the condition factor index seems to be low