The alpheid shrimp Athanas dimorphus Ortmann, 1894, common and widespread throughout the Indo-West Pacific, is reported for the first time from Brazil, representing the first invasive alpheid species in Brazil, and the first species of the genus Athanas Leach, 1816 introduced to the western Atlantic. The present record is based on several specimens collected at two localities in Ceará, Pedra Rachada beach near the town of Paracuru, and Meireles beach in Fortaleza. Athanas dimorphus is very common at the second site, suggesting that a population of this species is now established in northwestern Brazil. An updated list of marine and freshwater decapods accidentally or voluntarily introduced to Brazil is provided.

The present study is the first major assessment of the marine decapod fauna of Ceará, northeastern Brazil, since contributions of J. Fausto-Filho in the 1960s-1970s. A fully updated checklist of all decapod crustaceans occurring in marine and estuarine habitats of Ceará is provided, based on literature records, specimens held in two carcinological collections of the Universidade Federal do Ceará (UFC), and material collected mainly by the authors between 2011 and 2014. A total of 337 decapod species are listed, distributed among the following taxa: Achelata (8 species), Anomura (42 species), Astacidea (1 species), Axiidea (11 species), Brachyura (162 species), Caridea (83 species), Dendrobranchiata (20 species), Gebiidea (9 species), and Stenopodidea (1 species). Among them, 23 species represent new records for Ceará, with 14 species, viz. Alpheus peasei (Armstrong, 1940), A. thomasi Hendrix & Gore, 1973, Ambidexter symmetricus Manning & Chace, 1971, Axianassa australis Rodrigues & Shimizu, 1992, Biffarius biformis (Biffar, 1971), B. fragilis (Biffar, 1970), Leptalpheus axianassae Dworschak & Coelho, 1999, L. forceps Williams, 1965, Lysmata bahia Rhyne & Lin, 2006, L. intermedia (Kingsley, 1878), Merhippolyte americana Holthuis, 1961, Neocallichirus maryae Karasawa, 2004, Ogyrides hayi Williams, 1981, and Typton carneus Holthuis, 1951, now having Ceará as the northern-most limit in their distribution range along the Brazilian coastline. One shrimp species, Lysmata lipkei Okuno & Fiedler, 2010, which was also found in the state of Rio Grande do Norte, possibly represents an invasive taxon in Brazil and the western Atlantic, originating from the Indo-West Pacific. Alpheus buckupi Almeida, Terossi, Araújo-Silva & Mantelatto, 2013, previously recorded from Ceará based on a colour photograph, is confirmed from this state, with specimens from several new localities. A few doubtful records from Ceará are briefly discussed. Colour photographs are provided for most of the taxa newly recorded from Ceará; some species are illustrated in colour for the first time.

No abstract

Ototyphlonemertes is a cosmopolitan genus of meiofaunal nemerteans. Their morphological characters are insufficient to reliably identify and delimit species. Consequently, some of the species are considered cosmopolitan despite anticipated low dispersion capability of the adults and a short planktonic larval phase. Indeed, recent studies show that some species actually comprise cryptic species, and populations are connected by stochastic events of long-distance dispersion. Based solely on morphological traits, a Lactea and a Pallida morph of Ototyphlonemertes are recognized here from collections at eight and five locations respectively along the Chilean coast. To assess the phylogeographic patterns of their populations, two mitochondrial markers (COI and COX3) of 162 specimens of Lactea and 25 of Pallida were sequenced. Final sequences are 605bp and 362bp for COI and COX3, respectively. Results from phylogenetic and haplotype network analyses suggest that the Lactea morph comprises up to three independent evolutionary units (one with only COX3 sequences). A COI gene tree including other previously published Ototyphlonemertes sequences groups the Chilean Lactea with other Lactea, while the Chilean Pallida is grouped with other Pallida. Different structuring and gene flow patterns found for the four groups support the hypothesis that these are four independent evolutionary entities with different ecological, dispersal and demographical characteristics.

Of 45 species of nemerteans reported for the Brazilian coast, only two were recorded from Brazil's Northeast coast. Here we report seven new records for the state of Ceará, in Northeast Brazil: Tubulanus rhabdotus Côrrea, 1954, Carinomella cf. lactea Coe, 1905, Baseodiscus delineatus (Delle-Chiaje 1825), Cerebratulus cf. lineolatus Coe, 1905, Cerebratulus sp. 1, Cerebratulus sp. 2 and Lineidae sp. 1. Specimens were collected at the following beaches: Praia dos Dois Coqueiros, Praia do Pacheco, Pecém harbor, Praia da Pedra Rachada and Praia do Guajiru. T. rhabdotus is a new record for Northeast Brazil, Carinomella cf. lactea and Cerebratulus cf. lineolatus are new records for the South Atlantic Ocean and both genera are new records for Brazil.

The presence of cryptic species is fairly frequent in many invertebrate groups and even more so among invertebrates with simple morphology, such as nemerteans. Consequently, the use of molecular methods for species delimitation has become a needed tool to complement morphological analyses to better recognise such species. Nemertopsis bivittata is one example of species with subtle morphological variation, but ample geographic distribution, being a good candidate for a species complex study. Here we applied two mitochondrial genes, and 2903 single nucleotide polymorphism (SNP) variants in addition to morphological characters to investigate the presence of cryptic species among specimens previously identified as N. bivittata along the Brazilian Coast. To do so, specimens were collected at 15 different sites in the north-east, south-east and southern regions. Three new species of Nemertopsis are described based on morphological and molecular analyses: Nemertopsis caete sp. nov., Nemertopsis pamelaroeae sp. nov. and Nemertopsis berthalutzae sp. nov. The species N. pamelaroeae and N. berthalutzae present broad distributions from north-east to south-east; N. caete, however, is restricted to the north-east coast. This is the first study to use this combined approach in nemerteans and shows the advantages of integrating genomic markers with classical taxonomy, and applying objective approaches to delimiting species as independently evolving entities.

The superficially simple ciliated planktonic larvae of hoplonemerteans have been assumed to be lecithotrophic direct developers, even though many develop from such small eggs that it is hard to imagine how they could give rise to a viable juvenile without some phase of larval feeding. Indeed, attempts to raise such larvae to settlement without food invariably fail. Observations that some hoplonemertean larvae are found in plankton samples at a range of sizes, and much larger than hatchlings, suggest that they must indeed feed somehow. Because these so-called planuliform larvae lack apparent means to concentrate suspended algae or other unicellular food, one alternative hypothesis is that they are planktonic predators that hunt large prey.Here we provide direct evidence that this is indeed the case for six distinct species of hoplonemerteans. We recorded wild-caught larvae of Paranemertes californica, Paranemertes sp., Gurjanovella littoralis, Emplectonema viride, Carcinonemertes epialti, and Ototyphlonemertes sp. attacking, subduing, and devouring pelagic crustaceans, including barnacle nauplii, cyprids, copepods and their nauplii, and others. Although there is no doubt that some hoplonemerteans are genuine lecithotrophs, our evidence suggests that many species in this group both feed and grow during an extended planktonic larval period. This conclusion has important consequences for biogeographic and life history studies in this group, because it implies enhanced potential for longdistance dispersal. More broadly, the possibility that many animal larvae are actually carnivores invites reconsideration of prevailing stereotypes about metazoan developmental modes and the trade-offs between them.

Emplectonema viride Stimpson, 1857, a barnacle predator, is one of the most common and conspicuous intertidal nemerteans found along the West Coast of North America from Alaska to California, but it is currently referred to by the wrong name. Briefly described without designation of type material or illustrations, the species was synonymized with the Atlantic look-alike, Emplectonema gracile (Johnston, 1837) by Coe. Here we present morphological and molecular evidence that E. viride is distinct from E. gracile. The two species exhibit differences in color of live specimens and egg size and are clearly differentiated with species delimitation analyses based on sequences of the partial regions of the 16S rRNA and cytochrome c oxidase subunit I genes. In order to improve nomenclatural stability, we re-describe E. viride based on specimens from the southern coast of Oregon and discuss which species should be the type species of the genus. Emplectonema viride was one of the two species originally included in the genus Emplectonema Stimpson, 1857, but subsequent synonymization of E. viride with E. gracile resulted in acceptance of the Atlantic species, E. gracile, as the type species of the genus. We resurrect E. viride Stimpson, 1857 and following Corrêa’s designation, this should be the type species of the genus Emplectonema.