Water and sediment characteristics influence the distribution of ghost shrimps (axiidea) in the Persian and Oman Gulfs.

Ghost shrimps (Crustacea: Decapoda) demonstrate remarkable levels of niche selection and habitat diversity. Due to their cryptic life style, interactions between ghost shrimp assemblages and environmental parameters that potentially shape their local distribution are poorly understood. In the present study, ghost shrimp assemblages from the Persian Gulf (PG) and the Gulf of Oman (GO) were investigated to assess the main drivers determining their assemblage structure along a wide niche type and at a large geographic scale. During three large-scale oceanographic expeditions, sediments samples for biological and physicochemical analysis were collected by box corer (0.1 m2) from 62 stations. The spatial distribution of collected samples was evaluated based on sediment parameters obtained on grain size, total organic content (TOM) and carbonate, as well as water parameters including pH, temperature, depth, dissolved oxygen, chlorophyll α and salinity. Our results indicated a biodiversity hotspot for ghost shrimp in the north-western part of PG and the eastern part of GO. Aqaballianassa ehsani is the most frequent species in this research. DistLM analysis revealed that the abundance of ghost shrimps in the region is significantly corelated with TOM and Sand. Furthermore, a step-wise regression model highlighted that each ghost shrimp species is influenced by specific environmental factors. Our findings provide new insight in niche preferences of the two Michaelcallianassa congeners. While water and sediment parameters play a crucial role in determining the habitat preference of M. persica, only sediment parameters specify the favored niche of M. indica.

Response of marine amphipods to sediment variables (Chabahar Bay- Iran): A step toward localizing amphipod-based bioindices.

Chabahar Bay will undergo industrial and coastal pressures according to the government plan to develop the Makran coasts. Therefore, knowing its biological community as well as their possible interactions with environmental variables, before and after coastal development, is important. The amphipod community structure and their response to the structural and contaminant parameters of the sediment include: granulometry, total organic matter (TOM) overloading, heavy metal contamination based on the Pollution Load Index (PLI) and polycyclic aromatic hydrocarbons (PAHs) during post monsoon season of 2017 were investigated from 19 stations. Traditional diversity and taxonomic distinctness indices were calculated. Multivariate analysis revealed the main role of sediment grain size and depth in shaping amphipod community structure. Consequently, two specific ecological niches were determined: species that prefer non-muddy substrates; and those dwelling in muddy or muddy sandy biotopes. No correlation was found between the Shannon diversity (H'), the average taxonomic distinctness indices (Δ+) together and both with contamination parameters. The Δ+ funnel plot well separated under-stressed stations from the healthy ones. The presence of only Ampelisca congeners in under-stressed stations revealed the tolerant nature as well as species-specific response of the genus to anthropogenic impacts. Considerable tolerant response (P > 0.05, r2 = 0.4) of A. zamboangae to PAHs; A. persicus to TOM were observed. High concentration of nickel (Ni) in the studied area already stated due to erosion of ophiolite units from Makran Mountains. The significant correlation of the recently described Iranian species A. lowryi with Ni assumes that it is a native species that is well adapted to the geological conditions of the seabed. Instead Urothoe platydactyla can be considered as early warning signal for PAHs, TOM, Ni and cadmium (Cd) contamination particularly for non-muddy substrates. Our findings help to localize common biotic indices (e.g. AMBI, BENTIX, and BOPA) for studied area through correctly assignment of amphipods to the sensitive/tolerant ecological groups. Finally, we state that in the current situation of Chabahar Bay, in which no special industrial complexes have been established, any sediment-disrupting activity (i.e. sedimentation, dredging, trawling) affects its amphipod communities more than chemical pollutants.

Pleonexes Spence Bate, 1857 (Amphipoda: Ampithoidae) in the Persian Gulf and the Gulf of Oman.

A new species of ampithoid amphipod, Pleonexes nargessi, is described from the southern Iranian coasts of the Persian Gulf and the Gulf of Oman. The new species is the most similar to P. kava (Myers, 1985), but distinguished by the presence of the posterior tooth and the defining robust seta on the palm of male gnathopod 1, semi prehensile pereopod 5, and non-prehensile pereopods 6-7. Ampithoe qeshmensis Layeghi Momtazi, 2018 is transferred into Pleonexes.

A new species of Cephaloecetes (Bubocorophiina) from the Iranian coasts of the Gulf of Oman and the Hormuz Strait (Crustacea: Amphipoda: Siphonoecetini).

The first member of Cephaloecetes in the north-western part of the Indian Ocean, Cephaloecetes ungulatus sp. nov., is described from Chabahar Bay, the Gulf of Oman and Qeshm Island in the western Hormuz Strait, Iran. The new species is characterized from the other two species of genus Cephaloecetes by a unique claw-shaped ventral plate on antenna 2 article 2.

Anti-microfouling Activity of Glycomyces sediminimaris UTMC 2460 on Dominant Fouling Bacteria of Iran Marine Habitats.

Discovery of environmentally safe anti-fouling agent is currently of considerable interest, due to the continuous impact of biofoulers on the marine habitats and the adverse effects of biocides on the environment. This study reports the anti-adhesion effect of marine living Actinobacteria against fouling strains isolated from submerged panels in marine environments of Iran. The extract of Glycomyces sediminimaris UTMC 2460 affected the biofilm formation of Kocuria sp. and Mesorhizobium sp., as the dominant fouling agents in this ecosystem, up to 93.2% and 71.4%, respectively. The metabolic activity of the fouler bacteria was reduced by the extract up to 17 and 9%, respectively. This indicated the bactericidal potency of the extract on cells in the biofilm state that enables the compound to be effective even once the biofilms are established in addition to the inhibition of biofilm initiation. Moreover, extra polymeric substance (EPS) production by fouling bacteria was reduced by 60-70%. The absence of activities against fouling bacteria in suspension and also the absence of toxic effect on Artemia salina showed the harmless ecological effect of the anti-microfouling extract on the prokaryotic and eukaryotic microflora of the studied Iran marine ecosystem. Metabolic profiling of G. sediminimaris UTMC 2460 revealed the presence of compounds with molecular formulae matching those of known anti-fouling diketopiperazines as major components of the extract. These results suggest that the extract of Glycomyces sediminimaris UTMC 2460 could be used as a potentially eco-friendly viable candidate in comparison to the synthetic common commercial anti-microfouling material to prevent the fouling process in marine habitats of Iran.

Parhyale darvishi, a new widely distributed amphipod species, in the Persian Gulf and the Gulf of Oman (Crustacea, Amphipoda, Hyalidae).

Parhyale darvishi sp. nov., is described. The new species is characterized by a naked posterior margin on the propodus of pereopods 5-7, a special arrangement of robust setae on the first male gnathopod and a lack of dense fine setae on the second antennae. Parhyale darvishi sp. nov. is distributed from the western coasts of the Persian Gulf to the eastern coasts of Gulf of Oman.

New species and new record of hadzioids (Amphipoda: Senticaudata, Hadzioidea) from the Persian Gulf, Iran.

New record and new species of the families Melitidae Bousfield, 1973 and Maeridae Krapp-Schickel, 2008 are described from the Iranian shorelines of the Persian Gulf. Melita persia sp. nov. is differentiated from other members of M. zeylanica Stebbing, 1904 group by: the presence of two setae on inner ramus of third uropod, the setal arrangement on the telson, and a recurved proximal lobe of sixth coxa in females. Also, Elasmopus menurte Barnard, 1974 previously described from Western Australia and Mauritius is recorded, for the first time, from Persian Gulf in the north-western Indian Ocean.

Contribution to the knowledge of cotylean flatworms (Turbellaria, Polycladida) from Iranian coasts: Introducing a new species, with remarks on new records.

Very little information is available regarding marine free-living flatworms not only from Iran, but throughout the countries surrounding the Persian Gulf and the Gulf of Oman. The present study first introduces a new euryleptid species, and then reports four pseudocerotid polyclads which inhabit Iranian shallow rocky shores of the Persian Gulf and the Gulf of Oman. Maritigrella makranica sp. nov. is characterized dorsally by a medial cream or white reticulated appearance containing pale orange spots in a honeycomb pattern, a distinct orange submarginal band around the entire body margin and between the marginal tentacles, black spots scattered around mid-dorsal surface, becoming more sparse on raised median region and towards body margin, surrounded by a dark-grey halo around the body midline and orange-black halo towards margin. Three of the four pseudocerotids species belonging to the genera Pseudobiceros Faubel, 1984; Pseudoceros Lang, 1884; and Thysanozoon Grube, 1840, are new records for the studied areas, while the other has been reported in the Persian Gulf previously. Comments on Iranian species are provided and associations of flatworms with ascidians and sponges were observed. 

A new Imogine species (Turbellaria: Polycladida: Stylochidae) associated with rock oysters (Saccostrea cucullata) from the Persian Gulf, with a review of the genus.

A new species of acotylean polyclad, Imogine qeshmensis sp. nov. is described from Qeshm Island, Persian Gulf, Iran. I. qeshmensis is characterized by the number and arrangement of the tentacular, cerebral and frontal eyes, a body margin with opaque white bands and eyespots and a male genital complex with an highly muscular seminal vesicle equal in size to the prostatic vesicle.

Description of two new Discocelis species (Polycladida: Acotylea: Discocelidae) from the Persian Gulf with a review of the genus.

Two new polyclad species, from northern intertidal zone and shallow rocky shores of the Persian Gulf, Discocelispersica sp. nov. and Discocelis hollemani sp. nov., are described. D. persica possesses a thick and broadly oval body tapering somewhat posteriorly, without any obvious color pattern; with marginal eyes extended around the anterior margin of the body; cerebral eyes forming two clusters, each further subdivided into anterior and posterior groups, about 100 eyespots at the anterior group and 55 eyespots at the posterior groups; mouth at the posterior end of the pharynx; male atrium with three to four distinct lobes, with numerous prostatoid organs of two distinct sizes, without villus-like projections; and with a horseshoe-shaped Lang's vesicle. D. hollemani characterized by a thick and broadly oval body, not tapering antro-posteriorly, without any obvious color pattern; marginal eyes extended to the vicinity of the posterior end of pharynx; the cerebral eyes forming two clusters, each further subdivided into anterior and posterior groups in relation to the cerebral organ, about 50 eyespots at the anterior group and 20 eyespots at the posterior groups; mouth at the posterior end of the pharynx; the male atrium with two distinct lobes, with numerous prostatoids of two distinct sizes and different contents; villus-like projections absent, and with a horseshoe-shaped Lang's vesicle.