RESUMEN
The aim of present study was to examine the macro invertebrates as an assessment tool for characterization of the state of Bahrekan estuary in Persian Gulf, by using different biotic indices. An investigation on benthos was carried out during autumn 2008 to summer 2009 in the Bahrekan estuary (Persian Gulf). In order to identify and assess the benthic community structure, seasonal sampling was done from 21 stations with three replicates using van veen grab (./285 m2). The ecological indices, such as (AMBI, BI and Bentix), Shannon-Wiener index (H'), species richness (S) were applied to the available benthic species data, and evaluated comparatively. The grain size of sediments and total organic matter as essential factors in distribution and population diversity of macrobenthos communities were also analysed. According to the results, 17 groups of macrobenthos were identified. Out of 111 genus/species identified in this study, Gastropoda was the dominate group (79.8%), followed by Bivalvia (5.5%). Pyrgohydrobia sp. belonged to gastropoda was dominant in all of seasons. The results showed that all of the stations are characterized as muddy bottom and Bahrekan estuary are classified in slightly to moderate pollution status.
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Ecología , Animales , Invertebrados , Irán , Agua de MarRESUMEN
In this study, the Chesapeake Bay Benthic Index of Biotic Integrity (B-IBI) was selected in an attempt to describe ecological health of soft bottom channels (Khowr-e Musa) in North of the Persian Gulf. Most of study area was found to be in degraded or severely degraded conditions. B-IBI scores were ranged between 1 and 3.86. Comparison ofmacrobenthos abundance and organic content between two developmental periods showed significant difference (p < 0.05). After the establishment and development of petrochemical industries, the abundance of macrofauna decreased (809 to 239 individuals m(-2)) and organic content increased leading to organic enrichment (15.3 to 22.4%). Three new sources of organic matter were found to be important namely industrial waste, sewage and mangrove litter. After 1999 about 6 millions Avicennia marina tree were planted near petrochemical zone in the area. Study area changed rapidly in the last decade and region is under severely anthropogenic impacts. The present study showed that Khowr-e Musa is under both natural stress and anthropogenic impacts and two main impacts could be attributed to the organic enrichment and to the dredging. Choice of suitable management plans and metric controls could help to the salvage of the largest tidal channel complex in Persian Gulf.
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Ecosistema , Animales , Biodiversidad , Industria Química , Contaminación Ambiental , Océano Índico , PetróleoRESUMEN
Length-weight relationship and spawning season of Pickhandle barracuda, Sphyraena jello (C.) were studied for one year in Boushehr waters of the Persian Gulf. In the present study, 311 specimens were collected during November 2006 to October 2007. The samples composed of 151 (48.55%) male, 160 (51.45%) female; the sex ratio was M: F = 1 : 1.06. The b value ranged between 2.77 to 2.87 for male and female fishes, respectively. The relationship between body weight and length in total specimens was 2.82, indicating that this species show negative allometric growth. The peak spawning season of these fishes occur around spring, from April to June. The lowest Gonadosomatic Index recorded in August. The present study is the first record on length-weight relationship and spawning season of this species in the Persian Gulf region.
Asunto(s)
Pesos y Medidas Corporales , Peces , Reproducción/fisiología , Animales , Femenino , Peces/anatomía & histología , Peces/fisiología , Masculino , Estaciones del AñoRESUMEN
Abstract: The present information is based on the study of the zoeal stages of Hexapus sexpes. A single ovigerous female of Hexapus sexpes was collected from the North West Persian Gulf (29 degrees 56'14"S, 49 degrees 0288"W) in April 2009. Female was maintained in aquarium containing natural sea water at 25 degrees C until the eggs hatched. The present study describes the zoeal stages of Hexapus sexpes. A complete description and illustration of larval features is provided and a comparison with closely related species (Spiroplax spiralis and Lambdophallus anfractus) showing known larval development is presented. The zoeal stages of H sexpes are very similar to that of L. anfractus. The zoeal of two species, however, could separate by the number of setae on the maxillule and maxilla.