The coastal zone of the Oman Sea (Sistan and Baluchestan province) with 300 Km length is a rich habitat of different species of seaweeds. In order to determine the species identification and distribution of seaweeds, 11 stations were selected and samplings were carried out seasonally by scuba-diving method.During this study, 42 species of seaweeds were identified consist of: 3 species of green algae, 17 species of brown algae and 22 species of red algae. The dominant species of brown algae were: Stoechospermum marginatum, Padina australis, Dictyota sp., Sargassum glaucescens and Cystoseira indica.Some important and commercial species of red algae are: Gracilaria corticata, Gelidiella acerosa, Gelidium micropterum, Hypnea musciformis. The green algae were found only in Passabandar and Chabaharegions with the main species of Ulva fasciata.Along with sampling, some environmental factors were measured including: sea and ambient temperature, salinity, pH, growing depth, D.O., substrate structures and slope and transparency. The maximum and minimum growing depth of seaweeds were found in Tang and Gwatr areas, respectively.

Typical gobies are small in size and usually found as marine fishes. They inhabit on or whitin the substrates holes, and are mostly invisible. The present study identified two goby genera including Valenciennea and Gobiodon in Qeshm Island for the first time. Nuclear rhodopsin gene was sequenced in four goby species including G. citrinus, V. puellaris, V. sexguttata, as well as V. strigata. Furthermore, nuclear rhodopsin and mitochondrial cytochrome oxidase subunit I (COI) sequences of 38 Gobiidae species from GenBank were used to obtain a representative data-set in order to assess the phylogenetic position of the new samples and to compare the resultant tree with other related molecular reconstructions. Our phylogenetic tree was composed of two Clades. Clade 1 involved two genera including Gobiodon and Paragobiodon and Clade 2 involved three genera, including Valenciennea, Signigobius and Amblygobius. While, Valenciennea and Signigobius species were nested within Sub-Clade X, only Amblygobius species was nested within Sub-Clade Y. This study examined the phylogenetic relationships of four goby species using Rhodopsin and COI, as new markers. Our results on molecular phylogenetic analysis were in agreement with those of other studies using different molecular markers and morphological examinations.

The aim of this paper was to study monsoon effects on polychaetes population structure in Subtidal area based on some biodiversity indices. Sediments sampling was carried out by grab van-veen from 12 Subtidal stations in three time periods (pre-monsoon, monsoon and post-monsoon). The physical and chemical parameters were also recorded. Mean density of polychaetes were recorded 1101.2±614.3 ind/m2 (pre-monsoon), 428.9±316.2 ind/m2 (monsoon) and 588.8±313.3 ind/m2 (post-monsoon). Shanon diversity indices were 2.08, 1.63, 1.83 respectively. The Hill indices was reversed and showed highest number in monsoon season and minimum number in pre-monsoon. These results represented non-uniform polycheates distribution during pre-monsoon. Cluster analysis of each season showed that deep stations were in separate disturbances. During the summer monsoon, variations in environmental factors and bottom distractions affected the density and diversity of polychaetes and as a stressor reduced the diversity and density during the monsoon.

Total of 35 species of leucosiid crabs have been recorded by several authors and the current survey from the Persian Gulf Here, zoogeography of these species and their zoogeographical affinities within Indo-West Pacific region are discussed. In addition, present taxonomic survey of the Iranian coasts of the Persian Gulf resulted in finding 14 leucosiid crabs, of which Arcanio erinacea and Pariphiculus mariannae are new re cords for the area.

Introduction The family Blenniidae comprises 58 genera and 406 species according to Eschmeyer et al. (2018). Members of the family Blenniidae are small, scaleless and very agile fishes, inhabiting inshore, sub-tidal rocky substrata, and rock pools of the inter-tidal zone of tropical and sub-tropical marine waters (Randall, 1995). A few species are also reported from brackish and freshwaters (Hastings and Springer, 2009)....

The spatial distribution of the macrobenthos community was studied along the Iranian coasts of Persian Gulf of Bushehr province. Samples were collected with van Veen grab from intertidal (0 m) and Subtidal (depths 5 m and 10 m) zones at 16 stations determined in 6 transects, including 4 harbors (Genaveh, Bandargah, Rostami and Asaluyeh) and 2 creeks (Farakeh and Shif). A total of 17 groups (taxa) of macrobenthos were identified during research so that the most dominant assemblages belonged to Mollusca, Annelida, Arthropoda and miscellaneous groups, respectively. The average density (abundance) of macrofauna in depth*station ranged from 450 to 4380 ind/m2 and the average biomass (wet) ranged from 9 to 165 g/m2, also. Highest value of density and biomass were observed at 10 m and intertidal depths, respectively. Generally, the environmental parameters such as water depth, transect, sediments texture and organic matter found to influence the biological indices (density and biomass), ecological indices (diversity and richness) and structure distribution pattern of macroinvertebrates. In conclusion with increase depth and soft sediment was showed high density and decrease biomass. Also, density and biomass varied significantly (P<0.05 and P<0.01) which could be correlated with combination of different factors such as depth, transect, sediment characteristics, hydrodynamic conditions and marine pollution.

Among the many biochemical biomarkers used to assess contamination of the marine environment, metallothionein protein is considered as one of the very important and useful tool inrelated to biochemical markers metals. The aim of this study was to evaluate Metallothionein changes in natural condition in polychaete Glycinde bonhourei of 9 stations Chabahar Bay sub-tidal area from 2014 to 2015 with consideration before the monsoon season, monsoon, post-monsoon and concentrations of copper, zinc, cadmium in the polychaete tissue. Total average concentrations of copper and zinc and cadmium respectively recorded in the monsoon 6. 39± 2. 04, 20. 95± 4. 51, 0. 136± 0. 04 micrograms per gram dry weight of the monsoon season 3. 51± 1. 46, 11. 84± 2. 65, 0. 059 ± 0. 01 and in the post-Monsoon 4. 98 ± 1. 44, 16. 51± 3. 58, 0. 152± 0. 01 microgram per gram of dry weight that one-way analysis of variance showed significant difference between the station and seasons (P<0. 05). The total average of protein Metallothionein was calculated in pre-monsoon 28. 33 ± 5. 2, Monsoon 15. 50 ± 4. 9 and after Monsoon 21. 39± 4. 37 mcg/g that one-way analysis of variance showed significant difference between the station and seasons (P<0. 05). Pearson correlation test showed no significant differences between metals and biomarker changes that observed in any of the seasons and stations. This study showed that changes in biomarker metallothionein more than being under the influence of the concentration of heavy metals, can be caused due to environmental conditions of the sampling area and changes in the Gulf by Monsoon.

The physico_chemical factors such as temperature, dissolved oxygen, salinity, pH, total organic matter and grain size were studied in Subtidal region of 4 creeks in Mahshahr, Iran for a period of one-year (Aug. 1996 - July 1997). Relations between these factors and density of polychaetes which live in the bottom of creeks were evaluated. Process of water temperature changes was like as weather temperature changes but with less fluctuation. Salinity in all of these creeks is over 40 ppt and therefore they were among the hyperhaline creeks. Oxygen was in a high level and pH in the Bihad creek was less than 8.There were a Positive correlation between the total organic matter and silt-clay grains, furthermore these grains were dominant in the bottoms of all study areas. Temperature in Doragh and Ghazaleh creeks, salinity in Ghanam creek and silt-clay grains in Bihad creek had the most effect on the density of polychaetes.  

Polychaetes are important in determining the environmental status of seabed and their role in the food chain. Sampling of sediments in three areas of Beris, Ramin and Pasabandar was performed at 10 stations in the north of the Makoran Sea by Garb van-veen during three periods of pre-monsoon, monsoon, and post-monsoon winter with recordings of chemical physical parameters from November to March 2016. In the study identified 18 families of polychaetes communities it was found that the highest density in Monson period and in Post-Monsoon with 4364.67 ± 570 ind/m2 and the lowest density in Post-Manson period in Roman region with 225.33 ± 89 ind/m2.  In the pasaBandar area, the highest percentages belonged to the families Spionidae, Maldanidae and Cirratulidae, and to the families of Nephtydae, Phyllodocidae and Cirratulidae and to the Ramin family's Orbiniidae, Maldanidae and Cirratulidae. One-way ANOVA showed significant differences between stations and time periods (P <0.05). The highest densities of the polychaetes were estimated in terms of the period of Monsoon> Pre-Monsoon> Post-Monsoon period, respectively. Results of correlation between polychaete density and environmental factors of grain size sediment and TOM in pre-monsoon period showed a positive and significant correlation. There was no positive and significant correlation with environmental factors in monsoon period (P <0.05), but there was a significant positive correlation with grain size in post-monsoon period (p<0.05). The results showed that winter monsoon causes significant changes in the populations of the studied areas and the increase in density in monsoon can be due to the change of the currents direction and consequent increase of nutrient load in the area.

Nudibranches are the largest group of Hetrerobranches, (a sub-branch of Opisthobranchia) and are widespread and cosmopolitan species. They vary in shape and colors and occur in all waters from intertidal to deep sea zones and from polar to the tropics regions. Nudibranches are subdivided in two main groups including Anthobranchia and Cladobranchia. In the present study, based on morphology the svudied species was identified as Goniobranchus annulatus that belong to Anthrobranchia group. In molecular analysis the sequences of the partial mitochondrial COI gene of Goniobranchus annulatus species from Iran with 15 similar sequences of nudibrnaches from genbank were compared. Phylogenetic based on Neighbor_joining analyze showed a monophyly relationships between families of nudibranches and also revealed that Goniobranchus vibratus is a sister taxa to the Gonidbranchus annulatus from Iran Goniobranchus annulatus with 100% bootstrap support.