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.

Summary A new species of Tylenchidae from the rhizosphere of mangrove trees in Hormozgan and Khuzestan provinces, Iran, is described based on morphological and molecular data. Ottolenchus sinipersici n. sp., is characterised by a slightly fusiform body 560-665 μm long, lateral field in the form of a narrow band with two faint incisures that are not visible in fatter females, indistinct transverse annuli under the light microscope, cephalic region continuous with the body contour, smooth and flattened dorsoventrally, longitudinal and narrow sigmoid amphidial slits, stylet delicate, 10.1-11.2 μm long, with small rounded to slightly posteriorly sloping knobs, well-developed median bulb, offset and pyriform pharyngeal basal bulb, vulva located at 66.9-69.6% of body length, offset spermatheca, short post-vulval uterine sac, spicules 18.5-20.5 μm long with highly curved blades, and a 113-135 μm long filiform tail with a hook-like or coiled terminus. In Bayesian inference phylogenetic trees based on the partial small subunit ribosomal DNA (SSU rDNA) and D2-D3 expansion segment of large subunit ribosomal DNA (D2-D3 LSU rDNA) genes, the new species clustered together with O. facultativus (KJ869310) in SSU, and forms a clade with three isolates of O. discrepans in LSU phylogeny. Ottolenchus fungivorus n. comb. (= Filenchus fungivorus) is proposed.

This study presents length‐weight relationships (LWRs) of Liza klunzingeri (Day, 1888), Cociella crocodilus (Cuvier, 1829), Platycephalus indicus (Linnaeus, 1758) belonging to two Families (Mugilidae and Platycephalidae) from northern coastline of Gulf of Oman (Hormozgan province). Samples were collected by artisanal trawl and beach seine (both with 11 mm effective mesh size) monthly during 2010 to 2015. The presented models were highly significant (p < 0.01) with a reliable coefficient of determination (R2 > 0.90) that provides a reliable basic information for ichthyologists and fisheries scientists.

No abstract

Summary In this study, length‐length relationships (LLRs) and weight‐length relationships (WLRs) were established for a Carangidae species: Uraspis helvola and tow Flatfishes: Pseudorhombus elevatus and Psettodes erumei that are substantial marine fish species to commercial fisheries in Persian Gulf that are indigenous marine fish species in the region. Samples were collected by non‐selective fish bottom trawler with stretch mesh size of 4 centimeters at the cod‐end area, which helped us to obtain such a broad range size that included small, medium and large size classes during June to August 2017. Hitherto, the length‐weight model presented in this study for Pseudorhombus elevatus and Uraspis helvola were not documented on Fishbase. Additionally, new records of maximum length are presented as 64.5 and 30 centimeters for P. erumei and P. elevatus respectively. A comprehensive size distribution and highly significant fitted model (r2>0.95) in this research provides useful insight for future studies on fish biology, fisheries assessment and ecological modeling.