Fouling-Resistant Behavior of Hydrophobic Surfaces Based on Poly(dimethylsiloxane) Modified by Green rGO@ZnO Nanocomposites.

In line with global goals to solve marine biofouling challenges, this study proposes an approach to developing a green synthesis inspired by natural resources for fouling-resistant behavior. A hybrid antifouling/foul release (HAF) coating based on poly(dimethylsiloxane) containing a green synthesized nanocomposite was developed as an environmentally friendly strategy. The nanocomposites based on graphene oxide (GO) and using marine sources, leaves, and stems of mangroves (Avicennia marina), brown algae (Polycladia myrica), and zinc oxide were compared. The effectiveness of this strategy was checked first in the laboratory and then in natural seawater. The performance stability of the coatings after immersion in natural seawater was also evaluated. With the lowest antifouling (17.95 ± 0.7%) and the highest defouling (51.2 ± 0.9%), the best fouling-resistant performance was for the coatings containing graphene oxide reduced with A. marina stem/zinc oxide (PrGZS) and graphene oxide reduced with A. marina leaves/zinc oxide with 50% multiwall carbon nanotubes (PrGZHC50), respectively. Therefore, the HAF coatings can be considered as developed and eco-friendly HAF coatings for the maritime industry.

Discovery of Buea bangem Mvogo Ndongo, von Rintelen, Tomedi-Eyango & Cumberlidge, 2020 (Crustacea: Potamoidea: Potamonautidae: Liberonautinae) from Mt. Nlonako Wildlife Reserve, Cameroon.

N/A.

Phylogenetic evidence and morphological diagnosis for a new species of Parasesarma De Man, 1895 (Decapoda, Brachyura, Sesarmidae) from Sulawesi, Indonesia.

A new species of Parasesarma, P. rahayuae n. sp., is described from Sulawesi, Indonesia. Genetically, the new species is distinct from all other known species of Parasesarma and has a close phylogenetic relationship with P. anambas Yeo, Rahayu & Ng, 2004 and P. gemmatum Li, Shih & Ng, 2019. Morphologically, the new species most closely resembles P. anambas and P. gemmatum, but can be distinguished from these two species by the shape of the dactylar tubercles of the male chela and of the male first gonopod. This is the fourth species of Parasesarma recorded from Sulawesi, and with its description, the number of species assigned to the genus Parasesarma is 58.

Molecular phylogeography reveals multiple Pleistocene divergence events in estuarine crabs from the tropical West Pacific.

Due to the lack of visible barriers to gene flow, it was a long-standing assumption that marine coastal species are widely distributed, until molecular studies revealed geographically structured intraspecific genetic differentiation in many taxa. Historical events of sea level changes during glacial periods are known to have triggered sequential disjunctions and genetic divergences among populations, especially of coastal organisms. The Parasesarma bidens species complex so far includes three named plus potentially cryptic species of estuarine brachyuran crabs, distributed along East to Southeast Asia. The aim of the present study is to address phylogeography and uncover real and hidden biological diversity within this complex, by revealing the underlying genetic structure of populations and species throughout their distribution ranges from Japan to West Papua, with a comparison of mitochondrial COX1 and 16S rRNA gene sequences. Our results reveal that the P. bidens species complex consists of at least five distinct clades, resulting from four main cladogenesis events during the mid to late Pleistocene. Among those clades, P. cricotum and P. sanguimanus are recovered as monophyletic taxa. Geographically restricted endemic clades are encountered in southeastern Indonesia, Japan and China respectively, whereas the Philippines and Taiwan share two clades. As individuals of the Japanese clade can also be found in Taiwan, we provide evidence of a third lineage and the occurrence of a potential cryptic species on this island. Ocean level retreats during Pleistocene ice ages and present oceanic currents appear to be the main triggers for the divergences of the five clades that are here addressed as the P. bidens complex. Secondary range expansions converted Taiwan into the point of maximal overlap, sharing populations with Japan and the Philippines, but not with mainland China.

Phylogenetic relationships among the species of the Cameroonian endemic freshwater crab genus Louisea Cumberlidge, 1994 (Crustacea, Brachyura, Potamonautidae), with notes on intraspecific morphological variation within two threatened species.

Louisea Cumberlidge, 1994 (Crustacea, Brachyura, Potamonautidae) currently includes four endemic Cameroonian freshwater crab species whose phylogenetic relationships were previously unresolved. In the present study, phylogenetic analyses are carried out involving three mtDNA loci (COI, 12S rRNA, and 16S rRNA). The COI locus revealed divergence times of 5.6 million years ago (myr) for when L.balssi (Bott, 1959) diverged from L.edeaensis (Bott, 1969); 4.1 myr for when L.edeaensis diverged from L.yabassi Mvogo Ndongo, von Rintelen & Cumberlidge, 2019; and 2.48 myr for when the later species diverged from L.nkongsamba Mvogo Ndongo, von Rintelen & Cumberlidge, 2019. Three genetic lineages were found within L.nkongsamba that are supported by uncorrected p-distances and the haplotype network. Morphological variation in some taxonomically important characters was found within both L.nkongsamba and L.yabassi. No correlation, however, was found between the morphotypes within these species and the uncovered genetic lineages. Recognition of species boundaries and of subpopulations of species will prove valuable when making informed conservation decisions as part of the development of species action plans for these rare and threatened freshwater crabs.

Two new species of Leptarma (Decapoda, Brachyura, Sesarmidae) from the Western Indian Ocean with notes on their phylogeny.

Two new species of Leptarma, L. dispersum n. sp. and L. reunionense n. sp. are described from Europa Island and Réunion Island, respectively. Genetically, based on the mitochondrial COX1 gene, both species are markedly divergent from other congeneric species. Phylogenetically, L. dispersum n. sp. shows close relationship with L. lenzii (De Man, 1895) while L. reunionense n. sp. clusters with L. aurifrons (Li, Ng Shih, 2019) and the species pair L. moluccense (De Man, 1892) and L. paucitorum (Rahayu Ng, 2009). Morphologically, the new species differ most significantly from congeners by the relative length of the ambulatory legs and the shapes of the first gonopods and carapace. After the description of these two new species, the number of species comprised in the genus Leptarma is raised to 20, four of them being distributed in and off East Africa.

On the occurrence of Parasesarma cricotum (Rahayu amp; Davie, 2002 (Decapoda, Brachyura, Sesarmidae) in Palau and Sulawesi.

The occurrence of Parasesarma cricotum (Rahayu Davie, 2002) in Palau and Sulawesi is reported after the examination of several male and female specimens collected from Sulawesi, Indonesia, and Palau. The present record from Palau, has extended the distribution of P. cricotum considerably further northeast of its natural distribution range.

The Synonymy of the Supratidal Crab Species Parasesarma cognatum Rahayu & Li, 2013 with P. liho Koller, Liu & Schubart, 2010 (Decapoda: Brachyura: Sesarmidae) Based on Morphological and Molecular Evidence, with a Note on P. paucitorum Rahayu & Ng, 2009.

Parasesarma liho Koller, Liu & Schubart, 2010 and P. cognatum Rahayu & Li, 2013 from East and Southeast Asia are similar species that have been confused in several studies. Here, we re-examined the type specimens of both species and found identical main characters, which is supported by the molecular identity of the mitochondrial cytochrome oxidase subunit I gene. As a result, we treat P. cognatum as a junior subjective synonym of P. liho. We also show that the male paratype of P. paucitorum Rahayu & Ng, 2009 is conspecific with P. liho, although P. paucitorum s. str. remains a distinct but allied species. The distribution of P. liho is updated to include Japan (Ryukyus), Taiwan, Philippines (Cebu) and Indonesia (Sulawesi).

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.

Tetraclita ehsani sp. n. (Cirripedia, Tetraclitidae), a common intertidal barnacle from the Gulf of Oman, Iran.

A new species of intertidal acorn barnacle Tetraclita ehsanisp. n. was identified from the Iranian coast in the Gulf of Oman. Tetraclita ehsanisp. n. inhabits low exposed rocky shores and also attaches to shells of molluscs and the barnacle Megabalanus species. Parietes of Tetraclita ehsani ranged from white to pink which is different from Tetraclita serrata (in South African waters), which has green parietes. Morphology of the tergum and cirrus III of Tetraclita ehsanisp. n. is distinctive from other described West Indian Ocean species which have pink or white parietes (Tetraclita rufotincta, Tetraclita achituvi and Tetraclita reni). The tergum of Tetraclita ehsani is very narrow and the basal margin is slightly concave or straight, in contrast to Tetraclita rufotincta and Tetraclita reni, in which the tergum are board and with a very concave basal margin. Cirrus I anterior ramus of both Tetraclita ehsani and Tetraclita reni is antenniform and thus differing from the cirrus I of Tetraclita rufotincta (see Chan et al. 2009). Cirrus III of Tetraclita ehsanisp. n. is non-antenniform and lacks multicuspidate type setae, which is different from Tetraclita reni by having an antenniform cirrus III and with multicuspidate setae.