Entrapped by the uneven central and Middle Eastern terrains: Genetic status of populations of Hirudo orientalis (Annelida, Clitellata, Hirudinida) with a phylogenetic review of the genus Hirudo.

Phylogenetic relationships between species of the genus Hirudo plus genetic variation in the entire distribution range of Hirudo orientalis were investigated based on mitochondrial (COI and 12S rDNA) and nuclear (ITS1+5.8S+ITS2) genome regions. The sister relationship of Hirudo orientalis and H. medicinalis was revealed with a high posterior probability. A broad and patchy distribution with minor genetic differences was observed in populations of H. orientalis along the central and Middle Eastern parts of Asia. The known distribution range occurred in topographically heterogeneous landscapes around the Caspian Sea. The demographic analysis suggests the selection of the COI locus under unfavourable respiratory conditions, but population size expansion cannot be fully rejected. The genetic variation trend indicated northward dispersal. Higher haplotype diversity in the South Caspian region potentially suggests the area as a historical refugium for the species. The vast dispersal is assumed to occur after the Pleistocene glaciations via vertebrate hosts.

A checklist of the barnacles (Crustacea: Cirripedia: Thoracica) of the Persian Gulf and Gulf of Oman with nine new records.

The present annotated checklist contains 43 species of thoracican barnacles known to date from the area, 33 and 26 from the Persian Gulf and the Gulf of Oman, respectively. Nine species are new records for the area including Amphibalunus subalbidus (Henry, 1973), Armatobalanus allium (Darwin, 1854), Chelonibia patula (Ranzani, 1818), Conchoderma hunteri (Owen, 1830), Lepas anserifera Linnaeus, 1767, Lithotrya valentiana Reinhardt, 1850, Megabalanus coccopoma (Darwin, 1854), Megabalanus occator (Darwin, 1854) and Platylepas hexastylos (Fabricius, 1798), of which A. subalbidus and M. coccopoma are reported as alien species from the region.

Intertidal caprellids (Crustacea: Amphipoda) of the Persian Gulf and the Gulf of Oman, with description of three new species.

In the present contribution, intertidal caprellids of the Persian Gulf and the Gulf of Oman were studied. Materials were collected, from 40 localities, with a variety of habitats, along the Iranian coasts. Three new species are described including; Metaprotella macoranicus sp. nov, Monoliropus kazemii sp. nov, Pseudaeginella hormozensis sp. nov and Pseudocaprel-linapambanensis is reported from studied area. Metaprotella macoranicus sp. nov., is characterized with clear suture between head and pereonite 1, second peduncle article larger than third ones in first antenna, tuft and three long setae in abdominal appendages and reduced mid-dorsal projections in pereonite 3. Monoliropus kazemii sp. nov., possesses biarticulate abdominal appendage, straight second male gnathopod and setal formula with two apical and two medial setae. The main diagnostic character of Pseudaeginella hormozensis sp. nov., is reduced dorsal projection, bearing mid-lateral projection on pereonite 2-5 and robust pereopod 5 with grasping spines on propodus.

Mesozooplankton communities related to water masses in the Persian Gulf and the Gulf of Oman.

The spatial and temporal variations of mesozooplankton in relation to environmental parameters were investigated in the Persian Gulf and the Gulf of Oman. For this purpose, the physicochemical parameters were measured using a CTD probe and mesozooplankton were sampled vertically using a closing net aboard the RV Persian Gulf Explorer during two expeditions. Results showed a relationship between mesozooplankton assemblages and water mass distributions. Four mesozooplankton cluster station groups divided the sampled stations into masses, which was also confirmed by the PERMANOVA test. Overall, ninety taxa were identified that were dominated by copepods and characterized by small cyclopoids. Based on the results the mesozooplankton communities of the Persian Gulf and the Gulf of Oman are mostly shaped by the combined effect of temperature, salinity, and dissolved oxygen that significantly influences mesozooplankton occurrence during summer and spring.

Adding the Molecular Diversity Information of the Common Fouling Barnacle Amphibalanus amphitrite (Darwin, 1854) (Crustacea: Cirripedia) from the Persian Gulf and Gulf of Oman to the Global Diversity Pattern.

The balanid barnacle, Amphibalanus amphitrite, is known as one of the most common fouling species in the world. A phylogenetic study using material from around the world recovered three distinct clades for this species. Material from the Persian Gulf (PG) and the Gulf of Oman (GO) were not included in that survey. In the present study, we aimed to assess the genetic diversity of the balanid barnacles of these two gulfs and to evaluate their phylogeography. In total, 94 COI DNA sequences were obtained from the PG and the GO material. Most of these sequences clustered into a single clade, corresponding to clade I of the previous global study. However, two sequences, one from the PG and one from the GO, fell into a separate clade corresponding to clade III of the previous study. These two gulfs share some common haplotypes, but host several unique ones that are separated from the most common haplotype mainly by a single mutation. Based on various indices, the genetic diversity of the PG material was higher than that of the GO. Low values of ΦST show a regular gene flow among the stations and the two gulfs. The Bayesian skyline plots and the mismatch distribution analyses both showed signs of a recent population expansion in the PG and the GO. We also modeled the potential distribution areas for A. amphitrite to reveal the separate suitable habitats for the clades. The current phylogeographic status and genetic diversity of A. amphitrite in the PG and GO appears to have been shaped by both historical events and recent human activities.

Mesozooplankton community in near-hypoxic and hypoxic layers of the Persian Gulf and the Gulf of Oman.

To assess the role of near-hypoxic and hypoxic conditions on the mesozooplankton community, we studied twenty stations in the Persian Gulf and the Gulf of Oman. The physicochemical parameters were measured using a CTD probe and mesozooplankton were sampled vertically using a closing net. Results showed the hypoxic conditions of 0.52 ± 0.11, 1.40 ± 0.48, and 0.84 ± 0.08 in the lower layers in stations T11S3, T0S8B, and T9S5 in the Gulf of Oman and near-hypoxic conditions in station T6S3 (2.99 ± 0.05) in the Persian Gulf. The marginal test revealed that stratification during summer and dissolved oxygen and salinity during spring in the Persian Gulf and temperature, stratification, and dissolved oxygen during spring in the Gulf of Oman significantly explained the variation of mesozooplankton composition in the study areas (p < 0.05). The present study reveals some general patterns of mesozooplankton assemblage in near-hypoxic and hypoxic conditions, but a future detailed investigation will be essential.

A new species of Galene de Haan, 1833 (Galenidae: Brachyura) from the middle Miocene of Zagros Mountains, Iran.

A new species of Galene de Haan, 1833 (Decapoda: Brachyura: Galenidae) is described from the Mid Miocene (Langhian) strata of the Mishan Formation exposed at two localities in Hormozgan Province, Zagros Mountains, Iran. The galenid species, Galene dashtbani n. sp. is considered as the oldest representative of the genus and simultaneously the westernmost occurrence of all fossil and extant congeners known to date. The genus is currently limited to the Indo-West Pacific region. The present fossil occurrence of the genus suggests a Tethyan origin and subsequent migration eastward.

An updated checklist of caridean shrimps of the Persian Gulf and Gulf of Oman.

The material of the present checklist has been collected from the Iranian intertidal and shallow subtidal shores of the Persian Gulf and Gulf of Oman from 2015 to 2019, in addition to re-examining all the materials deposited in the Zoological Museum of the University of Tehran. This checklist providing 16 new records for the Persian Gulf and 15 for the Gulf of Oman raised the number of recorded caridean shrimps to 109 and 49 for these gulfs, respectively. However, the actual number of these shrimps are higher than these numbers due to two facts. Firstly, most of the subtidal diverse ecosystems, e.g. coral reefs and seagrass bed have not been seriously investigated taxonomically. Secondly, there are some members of species complexes and probably some new species in the study which need to be carefully treated.

New species of Caprella (Crustacea: Amphipoda) from the Gulf of Oman, Iran.

Caprella moradi sp. nov. is described from intertidal zone of the Gulf of Oman, Iran. This species is differentiated from the most similar species Caprella danilevskii (Czerniavski, 1868), by four rows of fine setae on the body surface and bears a curved anterior surface of propodus in the second male gnathopod.

A new sponge-dwelling species of Synalpheus Spence Bate, 1888 (Decapoda: Caridea: Alpheidae) from the Persian Gulf.

The present study is based on material collected in the intertidal and shallow subtidal areas of two Islands in the Persian Gulf, Abu-Musa and Larak. The new species, Synalpheus pentaspinosus n. sp., is closely related to S. quinquedens Tattersall, 1921. These two species share a very characteristic, sixth pleonite armed posteriorly with five stout sharp teeth, a feature unique within the genus. The color of ovaries or freshly laid eggs, red-orange in S. pentaspinosus n. sp. vs. green in S. quinquedens, is the most obvious character, by which the new species may be distinguished from S. quinquedens in the field. In addition, the two species can be separated by two characters on the dactylus of the minor cheliped. In the new species, the dactylus is furnished with two prominent rows of setae, one dorsally and one mesially, and has a small concavity on the cutting edge, contrasting to only one mesial row of setae and no obvious concavity in S. quinquedens.

Antennular sensory organs in cyprids of balanomorphan cirripedes: standardizing terminology using Megabalanus rosa.

Cirripedes are one of the major groups of fouling organism in the marine environment. The cyprid can, before a permanent attachment, actively explore and walk on the substratum using its antennules in a bipedal fashion without leaving the surface. Studying the structure of the cyprid antennule is therefore important for understanding the events that culminate in biofouling by barnacles. There are at present no complete, standardised accounts of the structure of the cyprid antennules in thoracican barnacles, and moreover, the existing accounts vary in their use of terminology. This article describes the cyprid antennule of the barnacle Megabalanus rosa. This barnacle species is common in E Asia, and the cyprids have previously been used in several biofouling studies. All externally visible setae on the antennules have been mapped; these comprise both chemosensors with a terminal pore, a putative aesthetasc-like seta and mechano-sensory setae. More setae were found on the attachment disc than in previous scanning electron microscope-based studies, but not all structures that can be seen with transmission electron microscopy were visible. The disc itself seems to have a variable surface area, which could assist in exploring rough surfaces. The various lengths of the antennular setae, coupled with the disposition of the segments, enable the cyprid to cover a wide swath of substratum during exploratory walking. A new terminology is proposed for cyprid antennular setae, which will form a basis for future comparative and functional studies of cirripede settlement.

Annotated checklist of the snapping shrimps of the genus Alpheus Fabricius, 1798 (Crustacea: Decapoda: Alpheidae) from the Persian Gulf and Gulf of Oman, Iran.

In the present study, shrimps belonging to the genus Alpheus from the Persian Gulf and Gulf of Oman are documented based on the existing literature and extensive new sampling from 2013 to 2018 along the Iranian coast. A total of 35 species are recorded from the region, of which 40% (14 species) and 60% (21 species) are new records for the Persian Gulf and Gulf of Oman, respectively. Among 19 sampling localities, A. lobidens De Haan, 1849, A. edwardsii (Audouin, 1826) and A. edamensis De Man, 1888 occurred in 14, 13 and 9 localities, respectively. Among the visited habitats, 14 species (40%) were associated with coral or other sessile invertebrates, 13 species (37%) were collected on sandy or rocky substrates, five species (14%) were obtained from muddy substrates, and three species (9%) were found associated with goby fishes. Among Alpheus species, three (10%) were endemic to the Persian Gulf. Most taxa show affinities to both western Indian Ocean and East Indian/West Pacific Oceans.

Cirripede Cypris Antennules: How Much Structural Variation Exists Among Balanomorphan Species from Hard-Bottom Habitats?

Barnacle cypris antennules are important for substratum attachment during settlement and on through metamorphosis from the larval stage to sessile adult. Studies on the morphology of cirripede cyprids are mostly qualitative, based on descriptions from images obtained using a scanning electron microscope (SEM). To our knowledge, our study is the first to use scanning electron microscopy to quantify overall structural diversity in cypris antennules by measuring 26 morphological parameters, including the structure of sensory organs. We analyzed cyprids from seven species of balanomorphan barnacles inhabiting rocky shore communities; for comparison, we also included a sponge-inhabiting balanomorphan and a verrucomorphan species. Multivariate analysis of the structural parameters resulted in two distinct clusters of species. From nonmetric multidimensional scaling plots, the sponge-inhabiting Balanus spongicola and Verruca stroemia formed one cluster, while the other balanomorphan species, all from hard bottoms, grouped together in the other cluster. The shape of the attachment disk on segment 3 is the key parameter responsible for the separation into two clusters. The present results show that species from a coastal hard-bottom habitat may share a nearly identical antennular structure that is distinct from barnacles from other habitats, and this finding supports the fact that such species also have rather similar reactions to substratum cues during settlement. Any differences that may be found in settlement biology among such species must therefore be due either to differences in the properties of their adhesive mechanisms or to the way that sensory stimuli are detected by virtually identical setae and processed into settlement behavior by the cyprid.

Five new records and an annotated checklist of the leeches (Annelida: Hirudinida) of Iran.

The present checklist contains 22 species belonging to 14 genera of six families of leeches known to date from Iran. Five species including Dina punctata punctata Johannson, 1927, Erpobdella monostriata (Lindenfeld & Pietruszynski, 1890), E. vilnensis (Liskiewicz, 1925), Trocheta haskonis Grosser, 2000 and Glossiphonia concolor (Apathty, 1888) are new records for the country.

Drastic underestimation of amphipod biodiversity in the endangered Irano-Anatolian and Caucasus biodiversity hotspots.

Biodiversity hotspots are centers of biological diversity and particularly threatened by anthropogenic activities. Their true magnitude of species diversity and endemism, however, is still largely unknown as species diversity is traditionally assessed using morphological descriptions only, thereby ignoring cryptic species. This directly limits evidence-based monitoring and management strategies. Here we used molecular species delimitation methods to quantify cryptic diversity of the montane amphipods in the Irano-Anatolian and Caucasus biodiversity hotspots. Amphipods are ecosystem engineers in rivers and lakes. Species diversity was assessed by analysing two genetic markers (mitochondrial COI and nuclear 28S rDNA), compared with morphological assignments. Our results unambiguously demonstrate that species diversity and endemism is dramatically underestimated, with 42 genetically identified freshwater species in only five reported morphospecies. Over 90% of the newly recovered species cluster inside Gammarus komareki and G. lacustris; 69% of the recovered species comprise narrow range endemics. Amphipod biodiversity is drastically underestimated for the studied regions. Thus, the risk of biodiversity loss is significantly greater than currently inferred as most endangered species remain unrecognized and/or are only found locally. Integrative application of genetic assessments in monitoring programs will help to understand the true magnitude of biodiversity and accurately evaluate its threat status.

Annotated checklist of the decapod crustaceans of the Gulf of Oman, northwestern Indian Ocean.

The decapod crustaceans of the Gulf of Oman have been documented based on the published literature and new sampling along the Iranian coast between 2005 and 2015. A total of 121 species were collected along the Iranian coast, of which 43 are new records for the Gulf of Oman. The Decapoda of the Gulf is currently represented by 258 species belonging to five infraorders: Axiidea, Achelata, Anomura, Brachyura, and Caridea. Brachyura, with 176 species, are the best represented group, followed by Anomura and Caridea with 42 and 17 species, respectively. The least diverse groups are Achelata, with five species, and Axiidea, with three. On the basis of the available information, the northern (Iranian) coast with 189 species is more diverse than the southern (United Arab Emirates and Oman) coast with 134 species.

Making future taxonomy of Niphargus (Crustacea: Amphipoda: Niphargidae) in the Middle East easier: DELTA database of Middle East species with description of four new species from Iran.

Four new species from the amphipod genus Niphargus are described, namely N. borisi sp. nov., N. bisitunicus sp. nov., N. darvishi sp. nov. and N. sharifi sp. nov. All four species of this predominantly subterranean genus were collected from springs in the Western region of Iran (Zagros region), which is the eastern borderline of the genus range. The species are morphologically diagnosed, described and illustrated. With these newly described species, the total number of Niphargus species in the Middle East reaches twenty-three. In order to facilitate the identification of Niphargus species in the region and to make future taxonomy of the genus easier, we have compiled a database in DEscription Language for TAxonomy (DELTA) using 23 diagnostic traits for these 23 species and subspecies identified in the Middle East. The database is available on the web as supplementary material whereas the dichotomous identification key automatically generated from the database for routine use is provided as a part of the paper.

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.

A re-description of rare alpheid shrimp Amphibetaeus jousseaumei (Coutière, 1896) and escription of a new species of the genus Athanopsis Coutière, 1897(Crustacea: Decapoda: Alpheidae) from Iranian coast of the Persian Gulf.

A new record of rare alpheid shrimp Amphibetaeus jousseaumei (Coutière, 1896) (Decapoda: Caridea: Alpheidae) is presented based on material collected from Qeshm Island, Iran, the Persian Gulf. This is the first record of the species for the Iranian waters as well as the second record and re-description of A. jousseaumei from its original description given by Coutière (1896). Besides, a new alpheid shrimp species Athanopsis tarahomii sp. nov. is described from the same locality. The new species can be clearly separated from all remaining species of the genus Athanopsis by deep rostrum curved downward and the presence of well marked blunt extra-cornea tooth on carapace. 

Discovery of Hemilepistus elongatus Budde-Lund, 1885 (Isopoda, Oniscidea) in Iran: redescription and intraspecific character variability.

In the present study, Hemilepistus elongatus Budde-Lund, 1885 is reported from Iran for the first time, redescribed and its diagnostic characters are figured. This species reveals a high variability in morphological characters. The division of the species at the subspecific level can not be supported anymore. This species differs from other species of the genus by the unique shape of male pleopod-endopodite I.