No abstract

A total of 150 species belonging to five infraorders (Caridea, Stenopodidea, Thalassinidea, Anomura and Brachyura) are recorded from the Iranian coast of the Persian Gulf. About 17% (26 species) are new records for the area. The infraorder Brachyura shows the highest species richness with 83 species. The Anomura and Caridea, with 29 and 27 species, respectively, follow. The Thalassinidea is represented by 10 species, whereas Stenopodidea only by one. The species with the highest occurence are ranked as follows: Nanosesarma sarii Naderloo & Türkay, 2009 (Brachyura), Alpheus lobidens De Haan, 1850 (Caridea), Metopograpsus messor (Forskål, 1775) (Brachyura), Coenobita scaevola (Forskål, 1775) (Anomura), Diogenes avarus Heller, 1865 (Anomura), Pilumnopeus convexus Maccagno, 1936 (Brachyura) and Portunus segnis (Forskål, 1775) (Brachyura). Among the surveyed habitats, mixed rocky/cobble show the highest diversity with 99 (66%) recorded species, followed by sedimentary muddy-sandy substrates and mangroves with 40 (26%) and 24 species (16%), respectively. The least diverse habitat is sandy beaches with 6 species. The decapod fauna shows a predominance of wide ranging Indo-West Pacific species (43%) and a small degree of endemism (5%). A considerable number of species is restricted to the northwestern Indian Ocean (27%), supporting the presence of a zoogeographical subregion within the western Indian Ocean Province.

Benthic sampling was performed along all Iranian subtidal waters of the Persian Gulf during the years 2003 and 2004. A total of 56 species of crabs were caught from 174 stations using a trawler fishing net and Peterson grab. These species belong to 12 families, 15 subfamilies and 37 genera. The results of the present study revealed that families Portunidae, Leucosiidae and Pilumnidae have the highest species richness with 14, 13 and 13 species respectively. Zoogeographical analysis shows that a high proportion (27%) of the Iranian subtidal crabs have world distribution in the Northern part of Indo-West Pacific region and only two endemic species were found.

Macrofauna play a key role in the functioning of mangrove ecosystems. Nevertheless, our understanding of the diversity and functional structure of macrofaunal communities across different habitats in the mangrove forests of the Persian Gulf is limited. In this study, we investigated species diversity and biological trait patterns of macrofauna in different mangrove-associated habitats, i.e., encompassing actual mangrove forests, and adjacent Beaches and Creeks, which exhibit different levels of habitat heterogeneity. Samples were collected from the different habitats in five different locations, over four seasons. A total of 122 macrofauna taxa were identified. The diversity of species was higher in summer than in winter. In the Beach habitats, species diversity showed an increasing trend from land toward the mangrove, whereas in Creek habitats diversity decreased from the Creek toward the mangrove. Multivariate community analysis showed differences in the distribution of abundant species and biological traits across all habitats. Deposit-feeding, crawlers, medium-size, and free-living were the dominant trait modalities in all habitats. The similarities within habitats over the four seasons had the same specific pattern of species and biological trait abundance in the Beach and the Creek, increasing from the non-covered habitat into the mangrove trees. Although many species shared similar traits, the abundance-driven differences in trait expression between habitats showed the importance of habitat filtering. The results of this study will be useful in the conservation of mangrove forests and they give a deeper understanding of the ecological patterns and functions of benthic macrofaunal communities in the Persian Gulf.