Multiloci analyses suggest synonymy among Rhomboplites, Ocyurus and Lutjanus and reveal the phylogenetic position of Lutjanus alexandrei (Lutjanidae: Perciformes)

Lutjanidae comprises 21 genera and 135 species widespread throughout Atlantic, Indian and Pacific oceans. Nonetheless, the phylogenetic relationships of Lutjaninae remain uncertain. Furthermore, phylogenetic hypotheses for Lutjanus alexandrei, an endemic species from northeastern Brazilian coast, in Lutjanidae are absent so far. Therefore, we carried out multiloci analyses, combining both mitochondrial and nuclear DNA sequences in Lutjaninae species from Western Atlantic focusing on the controversial relationships among Lutjanus, Rhomboplites, and Ocyurus. Besides, we determined the phylogenetic position and dated the origin of L. alexandrei. The phylogenetics trees based on the 4.4 kb for 11 species corroborated the synonym among Lutjanus and the putative monotypic genera. For the dating of L. alexandrei, another nucleotide dataset (3.0 kb; 40 species) validated the genetic identity of this species that diverged from the sister taxon L. apodus between 2.5 - 6.5 Mya, probably as a result of the barrier caused by the muddy outflow from Orinoco and Amazon rivers along the coastal zone. This report is the most robust multiloci analysis to confirm the synonymy of the three genera of Lutjaninae from Western Atlantic and the first reliable inference about the phylogenetic relationships and origin of L. alexandrei.(AU)

A Família Lutjanidae compreende 21 gêneros e 135 espécies, distribuídas ao longo dos oceanos Atlântico, Índico e Pacífico. As relações filogenéticas dos Lutjaninae são incertas. Além disso, a espécie Lutjanus alexandrei, endêmica da costa nordeste do Brasil, não foi inclusa em nenhuma hipótese filogenética até o presente. Assim, realizamos uma análise integrando DNA mitocondrial e nuclear para espécies de Lutjaninae do Atlântico Ocidental, direcionada para a controversa relação entre Lutjanus, Rhomboplites e Ocyurus. Além disso, alocamos filogeneticamente L. alexandrei e datamos sua origem. As árvores filogenéticas baseadas em 4.4 kb de 11 espécies corroboraram a sinonímia entre os monotípicos e Lutjanus. Para a datação de L. alexandrei, outro banco de nuclueotídeos foi analisado (3.0 kb; 40 espécies), validando geneticamente a espécie e a colocando como irmã de L. apodus, da qual se separou entre 2.5 - 6.5 Mya, o que provavelmente foi provocado pela faixa enlameada na região costeira, influenciada pelas descargas dos rios Amazonas e Orinoco, que funciona como barreira. Este trabalho representa a mais robusta análise multiloci direcionada para a sinonimização dos três gêneros de Lutjaninae e a primeira hipótese filogenética a propor um posicionamento e origem para L. alexandrei.(AU)

Molecular authentication of Pargo fillets Lutjanus purpureus (Perciformes: Lutjanidae) by DNA barcoding reveals commercial fraud

The Caribbean Red Snapper (Pargo) Lutjanus purpureus is the most economically important snapper in Brazil, which is sold, among other forms, as frozen fillets. During the process of transformation into fillets there is the removal of the distinctive morphological traits, being able to favor the substitution by less valued species. In addition, there is no national legislation requiring the insertion of the specific name on the product label. However, according to a Normative Instruction (IN N ° 29/2015 MAPA) that correlates the common and specific names of the products destined to the national trade, in Brazil only L. purpureus and L. campechanus can be denominated "Pargo". Thus, the DNA barcode tool was used to identify the fillets sold in north of Brazil, labeled "Pargo", with the aid of sequences from the public and control databases. The results showed that among 142 fillets examined, 78% was identified as L. purpureus and 22% as Rhomboplites aurorubens, a snapper with low commercial value in the country, revealing commercial fraud. The molecular identification method successfully used in this study to authenticate fillets snappers may also be used by surveillance authorities in the quality control of processed fish products, towards ensuring consumer rights.(AU)

O Pargo Lutjanus purpureus, lutjanídeo mais importante economicamente no Brasil, é vendido, entre outras formas, como filés congelados. Durante a transformação em filés, há a remoção das características morfológicas distintivas, podendo favorecer a substituição por espécies menos valorizadas. Além disso, não há legislação nacional que exija a inserção do nome específico no rótulo. Porém, de acordo com uma Instrução Normativa (IN N° 29 /2015 MAPA) que correlaciona os nomes comuns e específicos dos produtos destinados ao comércio nacional, no Brasil somente L. purpureus e L. campechanus podem ser denominados "Pargo". Assim, a ferramenta DNA barcode foi usada para identificar os filés vendidos no norte do Brasil, rotulados como "Pargo", com o auxílio de sequências dos bancos de dados públicos e banco controle. Os resultados mostraram que entre os 142 filés examinados, 78% foi identificado como L. purpureus e 22% como Rhomboplites aurorubens, um lutjanídeo com baixo valor comercial no país, revelando fraude comercial. O método de identificação molecular, utilizado com êxito neste estudo para autenticar filés de lutjanídeos, pode também ser utilizado pelas autoridades de vigilância no controle de qualidade de produtos processados derivados de peixes em geral, para garantir os direitos dos consumidores.(AU)

Molecular analyses reveal the occurrence of three new sympatric lineages of velvet worms (Onychophora: Peripatidae) in the eastern Amazon basin

Abstract In the present study, we investigated the possible existence of new lineages of peripatids through comparisons between known Neotropical species and specimens obtained from two locations in Pará, a state in eastern Brazilian Amazonia using a molecular approach based on sequences of the mtDNA genes COI, 16Sr RNA, and 18S RNA. The analyses included also sequences of Asian and African taxa for a more systematic understanding of the phylogenetic relationships within the group. The analysis of the COI, 16S rRNA and 18S RNA sequences permitted the identification of three distinct lineages (A, B and C) based on two different phylogenetic approaches (Bayesian methods and ML). The three lineages presented here are completely distinct from all other peripatid taxa so far defined by molecular data. The presence of specimens of three independent onychophoran lineages occurring in sympatry in the Amazon basin was confirmed in all the analyses, providing consistent support for the phylogenies presented in this study. These findings reinforce the importance of the Amazon region in the diversification of Neotropical peripatids, and indicate that onychophoran diversity is much greater than previously thought, given that the number of taxa found at a single site was equivalent to the total number of allopatric species described for the entire region.

Genetic differentiation in populations of Aedes aegypti (Diptera, Culicidae) dengue vector from the Brazilian state of Maranhão

ABSTRACT Aedes (Stegomyia) aegypti is the vector responsible for the transmission of the viruses that cause zika, yellow and chikungunya fevers, the four dengue fever serotypes (DENV - 1, 2, 3, 4), and hemorrhagic dengue fever in tropical and subtropical regions around the world. The present study investigated the genetic differentiation of the 15 populations of this vector in the Brazilian state of Maranhão, based on the mitochondrial ND4 marker. A total of 177 sequences were obtained for Aedes aegypti, with a fragment of 337 bps, 15 haplotypes, 15 polymorphics sites, haplotype diversity of h = 0.6938, and nucleotide diversity of π = 0.01486. The neutrality tests (D and Fs) were not significant. The AMOVA revealed that most of the variation (58.47%) was found within populations, with FST = 0.41533 (p < 0.05). Possible isolation by distance was tested and a significant correlation coefficient (r = 0.3486; p = 0.0040) was found using the Mantel test. The phylogenetic relationships among the 15 haplotypes indicated the existence of two distinct clades. This finding, together with the population parameters, was consistent with a pattern of genetic structuring that underpinned the genetic differentiation of the study populations in Maranhão, and was characterized by the presence of distinct lineages of Aedes aegypti.

Development of EPIC-PCR Markers for Lutjanus purpureus (Lutjanidae-Perciformes) and their Potential Applicability in Population Analyses

ABSTRACT In the present study, a novel set of eight EPIC primers were developed for Lutjanus purpureus and assayed in five other marine teleosts including three lutjanids, one scianid and one anablepid. Most of the genomic regions used in this study presented genetic diversity indexes equal or greater than the intragenic regions commonly used in population genetics studies. Moreover, six out of eight markers showed cross-amplification with other taxa. Thus, the primers described here may be used to elucidate questions at the intraspecific level for a large number of taxa.

Novel Microsatellite Markers for Brazilian Mangrove Oysters ( Crassostrea gasar ) and their Cross-Amplification in Crassostrea rhizophorae

ABSTRACT A microsatellite CT/GT enriched genomic library was developed for Crassostrea gasar and twelve new polymorphic loci were isolated and characterized. The markers were successfully amplified from 25 individuals of Crassostrea gasar and 11 cross-amplified individuals of Crassostrea rhizophorae. There was no evidence of linkage between loci in either species.

Analysis of propagule pressure and genetic diversity in the invasibility of a freshwater apex predator: the peacock bass (genus Cichla)

An important step in invasive biology is to assess biological variables that could be used to predict invasion success. The study of genetics, evolution, and interactions of invasive and native species in invaded ranges provides a unique opportunity to study processes in population genetics and the capability of a species' range expansion. Here, we used information from microsatellite DNA markers to test if genetic variation relates to propagule pressure in the successful invasion of an apex predator (the Amazonian cichlid Cichla) into Southeastern Brazilian River systems. Invasive populations of Cichla have negatively impacted many freshwater communities in Southeastern Brazil since the 1960s. Reduction of genetic variation was observed in all invasive populations for both Cichla kelberi (CK) and Cichla piquiti (CP). For instance, heterozygosity was lower in the invasive range when compared to native populations from the Amazon basin (CP HE = 0.179/0.44; CK HE = 0.258/0.536 respectively). Therefore, despite the successful invasion of Cichla in southeast Brazil, low genetic diversity was observed in the introduced populations. We suggest that a combination of factors, such as Cichla's reproductive and feeding strategies, the "evolutionary trap" effect and the biotic resistance hypothesis, overcome their depauperete genetic diversity, being key aspects in this apex predator invasion. Uma importante etapa na biologia da invasão é acessar variáveis biológicas que podem predizer o sucesso de invasão. O estudo da genética, evolução e interações entre invasores e espécies nativas no ambiente invadido pode prover uma oportunidade única para o estudo dos processos em genética de populações e a capacidade de uma espécie ampliar seu habitat. Nesse trabalho, nos utilizamos dados de marcadores de DNA microssatélites para testar se a variação genética é relacionada a pressão de propágulo na invasão bem sucedida do predador de topo (o ciclídeo Amazônico Cichla) nos rios do Sudeste Brasileiro. Populações invasoras de Cichla vem impactando negativamente diversas comunidades de água doce no Sudeste brasileiro deste 1960. A redução da variação genética foi observada em todas populações invasoras, tanto para Cichla kelberi (CK) como Cichla piquiti (CP). Por exemplo, a heterozigose foi menor no ambiente invadido quando comparada com as populações nativas da bacia Amazônica (CP HE = 0.179/0.44; CK HE = 0.258/0.536 respectivamente). Assim, apesar do sucesso da invasão de Cichla no sudoeste do Brasil, baixa diversidade genética foi observada nas populações introduzidas. Nós sugerimos que uma combinação de fatores, como as estratégias reprodutivas de Cichla, o efeito de "armadilha evolutiva" e a hipótese de resistências biótica superam o efeito que a diversidade genética depauperada exerce, sendo aspectos-chave na invasão desse predador de topo de cadeia.

Cytogenetic and DNA barcoding reveals high divergence within the trahira, Hoplias malabaricus (Characiformes: Erythrinidae) from the lower Amazon River

Molecular and cytogenetic data have provided evidence of cryptic speciation in the widespread South American trahira, Hoplias malabaricus. In the present study, karyotypes and DNA barcode sequences of specimens from seven populations inhabiting the lower Amazon River were analyzed in order to characterize the levels of genetic divergence within a single karyomorph. All the specimens presented karyotypes with 2n = 40 chromosomes (20m+20sm) that were consistent with the species' C karyomorph. The DNA barcodes revealed six haplogroups, with clear divergence between populations from Brazil and Argentina. The results support the species complex hypothesis and indicate that a single karyomorph of H. malabaricus may harbor more than one species...

Dados moleculares e citogenéticos tem evidenciado especiação críptica na traíra sul-americana, Hoplias malabaricus. No presente estudo, cariótipos e sequências de DNA barcode de espécimes de sete populações, habitando a região do baixo rio Amazonas, foram analisadas a fim de caracterizar o nível de divergência genética dentro de um único cariomorfo. Todos os espécimes possuem 2n = 40 cromossomos (20m+20sm) os quais são inseridos no grupo de traíras do cariomorfo C. DNA barcode revelou seis haplogrupos, com clara divergência entre populações do Brasil e da Argentina. Os resultados apoiam a hipótese de complexo de espécies e indicam que um único cariomorfo de Hoplias malabaricus pode conter mais de uma espécie...

Occurrence of the Indo-Pacific freshwater prawn Macrobrachium equidens Dana 1852 (Decapoda, Palaemonidae) on the coast of Brazilian Amazonia, with notes on its reproductive biology

The freshwater prawn Macrobrachium equidens, which is native species of the Indo-Pacific Region, was recorded for the first time on the Amazon coast of Brazil. This species was found to inhabit the same environment as two native Macrobrachium species, M. amazonicum and M. acanthurus, and is morphologically very similar to the latter. The identification of the species was confirmed by the genetic analysis of sequences of the mitochondrial Cytochrome Oxidase (COI) gene. A detailed description of the morphological features and reproductive biology of M. equidens in this new environment is presented.

O camarão de água doce Macrobrachium equidens, nativo da região do Indo-Pacífico, foi registrada pela primeira vez na costa da Amazônia Brasileira. Esta espécie foi encontrada habitando o mesmo ambiente que duas espécies nativas do gênero Macrobrachium: M. amazonicum e M. acanthurus, e é morfologicamente muito similar à última. A identificação dessa espécie foi confirmada pela análise da seqüência genética do gene mitocondrial Citocromo Oxidase (COI). Uma descrição detalhada das características morfológicas e biologia reprodutiva de M. equidens neste novo ambiente é apresentada.

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: new insights from molecular data

The giant river prawn, Macrobrachium cf. rosenbergii, is one of the most cultivated freshwater prawns in the world and has been introduced into more than 40 countries. In some countries, this prawn is considered an invasive species that requires close monitoring. Recent changes in the taxonomy of this species (separation of M. rosenbergii and M. dacqueti) require a re-evaluation of introduced taxa. In this work, molecular analyses were used to determine which of these two species was introduced into Brazil and to establish the geographic origin of the introduced populations that have invaded Amazonian coastal waters. The species introduced into Brazil was M. dacqueti through two introduction events involving prawns originating from Vietnam and either Bangladesh or Thailand. These origins differ from historical reports of the introductions and underline the need to confirm the origin of other exotic populations around the world. The invading populations in Amazonia require monitoring not only because the biodiversity of this region may be affected by the introduction, but also because admixture of different native haplotypes can increase the genetic variability and the likelihood of persistence of the invading species in new habitats.

Molecular identification, phylogeny and geographic distribution of Brazilian mangrove oysters (Crassostrea)

Oysters (Ostreidae) manifest a high degree of phenotypic plasticity, whereby morphology is of limited value for species identification and taxonomy. By using molecular data, the aim was to genetically characterize the species of Crassostrea occurring along the Brazilian coast, and phylogenetically relate these to other Crassostrea from different parts of the world. Sequencing of the partial cytochrome oxidase c subunit I gene (COI), revealed a total of three species of Crassostrea at 16 locations along the Brazilian coast. C. gasar was found from Curuçá (Pará state) to Santos (São Paulo state), and C. rhizophorae from Fortim (Ceará state) to Florianópolis (Santa Catarina state), although small individuals of the latter species were also found at Ajuruteua beach (municipality of Bragança, Pará state). An unidentified Crassostrea species was found only on Canela Island, Bragança. Crassostrea gasar and C. rhizophorae grouped with C. virginica, thereby forming a monophyletic Atlantic group, whereas Crassostrea sp. from Canela Island was shown to be more similar to Indo-Pacific oysters, and either arrived in the Atlantic Ocean before the convergence of the Isthmus of Panama or was accidentally brought to Brazil by ship.

Identification and phylogenetic inferences on stocks of sharks affected by the fishing industry off the Northern coast of Brazil

The ongoing decline in abundance and diversity of shark stocks, primarily due to uncontrolled fishery exploitation, is a worldwide problem. An additional problem for the development of conservation and management programmes is the identification of species diversity within a given area, given the morphological similarities among shark species, and the typical disembarkation of processed carcasses which are almost impossible to differentiate. The main aim of the present study was to identify those shark species being exploited off northern Brazil, by using the 12S-16S molecular marker. For this, DNA sequences were obtained from 122 specimens collected on the docks and the fish market in Bragança, in the Brazilian state of Pará. We identified at least 11 species. Three-quarters of the specimens collected were either Carcharhinus porosus or Rhizoprionodon sp, while a notable absence was the daggernose shark, Isogomphodon oxyrhyncus, previously one of the most common species in local catches. The study emphasises the value of molecular techniques for the identification of cryptic shark species, and the potential of the 12S-16S marker as a tool for phylogenetic inferences in a study of elasmobranchs.

Genetic characterization of native and introduced populations of the neotropical cichlid genus Cichla in Brazil

A molecular phylogenetic analysis based on mitochondrial 16S ribosomal DNA and Control Region sequences from native and introduced populations was undertaken, in order to characterize the introduction of Cichla (peacock bass or tucunaré) species in Brazil. Mitochondrial DNA haplotypes found in introduced fish from Minas Gerais state (southeastern Brazil) clustered only with those from native species of the Tocantins River (Cichla piquiti and C. kelberi), thereby suggesting a single or, at most, few translocation acts in this area, even though with fish from the same source-population. Our study contributes to an understanding of the introduction of Cichla in regions of Brazil outside the Amazon basin, and adds phylogenetic data to the recently describe Cichla species, endemic from the Tocantins-Araguaia basin.

Genetic characterisation of populations of the critically endangered Goliath grouper (Epinephelus itajara, Serranidae) from the Northern Brazilian coast through analyses of mtDNA

The Goliath grouper (Epinephelus itajara) is one of the most endangered species of fish of the subfamily Epinephelinae. Slow to develop and mature, and dependent on mangrove habitats for breeding, the species also suffers intense harvesting, which has reduced drastically in numbers in many areas. To contribute to the understanding of the characteristics of E. itajara populations, we conducted a molecular genetics study of the species, focusing on populations from the Northern Brazilian coast. The mtDNA control region (D-loop) of 116 individuals from five localities (Bragança, Ajuruteua, Parnaíba, Fortaleza and Natal) was analysed, and a sequence of 499 base pairs identified. Analyses of the sequences indicated that genetic variability was generally lower in E. itajara than in other endangered species of the genus. AMOVA found no significant grouping structure among the populations. Nested Clade Analysis revealed a significant association between genetic variability and geographic distribution among only three populations (Ajuruteua, Parnaíba and Natal). Genetic diversity was higher in populations from the Amazon region, which may be related to the better conservation of mangrove habitats in this area. Therefore, the present study could be used for the implementation of conservation and management measures in order to protect and consolidate these populations.

Can Lutjanus purpureus (South red snapper) be "legally" considered a red snapper (Lutjanus campechanus)?

Red snappers (Lutjanus purpureus in Brazil and Lutjanus campechanus in USA and Gulf of Mexico) are both under clear effect of overfishing. Because of their high morphological similarity it has already been suggested that they could possibly be considered as a single species. To investigate the degree of similarity and the genetic structure of red snapper populations we constructed a common dataset of partial D-loop mtDNA sequences of L. purpureus from Brazil (Amapá, Pará and Maranhão) and L. campechanus from the Atlantic coast of the USA (Florida, Louisiana and Mississippi). Phylogenetic and population genetic analyses surprisingly depicted high similarity between L. campechanus and L. purpureus, compatible with the hypothesis of a single species of red snapper for the Western Atlantic Ocean. These preliminary but very curious findings open an important discussion regarding the legislation involved on the capture of this overexploited fish resources as well as regarding their taxonomy.

Low levels of genetic diversity depicted from mitochondrial DNA sequences in a heavily exploited marine fish (Cynoscion acoupa, Sciaenidae) from the Northern coast of Brazil

The acoupa weakfish (Cynoscion acoupa - Sciaenidae) is a marine species of croaker with estuarine-dependent behavior, found in the western Atlantic from Panama to Argentina. It is one of the most exploited food fish on the northern coast of Brazil. In this study, DNA sequences were determined from the entire control region (D-loop) of the mitochondrial genome of 297 individuals collected during seven different months between December 2003 and August 2005 on the northern coast of Brazil (Amapá and Pará). Genetic variability expressed by haplotype (h = 0,892) and nucleotide (pi = 0,003) diversities were low compared to other heavily exploited marine fish species from the western Atlantic and eastern Asia. AMOVA depicted a lack of genetic structuring among the samples from different years, indicating the presence of a single stock of C. acoupa within the sample area. The possible reasons for the low levels of genetic diversity are discussed. These results demonstrate a need for the monitoring of C. acoupa harvesting and the preservation of the estuaries within its geographic range, considering that this large fish depends on estuarine ecosystems during part of its life cycle.

Novel 12S mtDNA findings in sloths (Pilosa, Folivora) and anteaters (Pilosa, Vermilingua) suggest a true case of long branch attraction

We sequenced 12S RNA mtDNA for the majority of the extant species of sloths and anteaters and compared our results with previous data obtained by our group using 16S RNA mtDNA in the same specimens and to GenBank sequences of the extinct giant sloth Mylodon. Our results suggest that pigmy-anteaters may be a case of the long-branch attraction phenomenon and also show the large genetic difference between the Amazonian and Atlantic forest three-toed sloths, contrasting with the small differences observed between the two non-Atlantic forest forms of sloths. These results have important implications for the taxonomy of sloths and anteaters and strongly suggest the placement of pigmy anteaters in their own family (Cyclopidae) and raising the taxonomic status of Bradypus torquatus to a genus.

Tocantins river as an effective barrier to gene flow in Saguinus niger populations

The Saguinus represent the basal genus of the Callitrichinae subfamily. Traditionally this genus is divided into three groups: Hairy, Mottled and Bare-face, however, molecular data failed to validate these groups as monophyletic units, as well as raised some subspecies to the species status. This is the case of the former subspecies Saguinus midas midas and S. midas niger, which are now considered as different species. In the present study, we sequenced a portion of the D-loop mtDNA region in populations from the East bank of the Xingu and from both banks of the Tocantins river, in order to test the effectiveness of large rivers as barriers to the gene flow in Saguinus. According to our results, the populations from the East and West banks of the Tocantins river are more divergent than true species like S. mystax and S. imperator. The Tocantins river may be acting as a barrier to gene flow, and consequently these very divergent populations may represent distinct taxonomic entities (species?).

Molecular discrimination of pouched four-eyed opossums from the Mamirauá Reserve in the Brazilian Amazon

Previous cytochrome B (CytB) mtDNA studies have suggested four species for the opossum genus Philander (four-eyed opossums), three (P. mcilhennyi, P. andersoni and P. opossum) from the Amazon and one (P. frenata) from the Brazilian Atlantic forest. During a faunal survey nine specimens of Philander sp. and four of Didelphis marsupialis were collected in the Mamirauá Sustainable Reserve, Amazonas State, Brazil. Preliminary analyses based on morphology and geographical distributions were not conclusive, suggesting that Philander specimens could belong to either P. andersoni or P. opossum. In order to elucidate the relationship of this taxon to the remaining Amazonian taxa, seven Philander and two Didelphis specimens animals were sequenced for the cytB mtDNA gene and compared to other previously studied taxa. The maximum likelihood (ML), neighbor-Joining (NJ) and maximum parsimony (MP) consensus bootstrap trees depicted six groups: Didelphis., P. frenata, P andersoni, P. mcilhennyi, P.o. opossum and Philander sp. and Philander canus in a common assemblage supported by significant bootstrap values, suggesting that the Philander sp. from Mamiraua in fact belongs to the species Philander canus.

The morphology of the foregut of larvae and postlarva of Sesarma curacaoense De Man, 1892: a species with facultative lecithotrophy during larval development

Previous study on the resistance of larvae of Sesarma curacaoense submitted to starvation has revealed a facultative lecithotrophy during zoeal stages, but megalopa and first juvenile stages are exclusively feeding stages. In the present study, the gross morphology and fine structure of the foregut of S. curacaoense were investigated during larval, megalopa and first juvenile stages. The foregut of the zoea I show specific setae and a filter press apparently functional. The foregut undergoes changes in the zoea II (last larval stage) with increment of setae number, mainly on the cardiopyloric valve and complexity of the filter press. After metamorphosis to megalopa stage the foregut become rather complex, with a gastric mill supporting a medial and two lateral teeth well-developed. The foregut of the first juvenile is more specialized compared to the previous stage, showing similar characteristics of the decapod adults. These results provide further evidence of facultative lecithotrophic development in the larvae of S. curacaoense.

Estudo prévio sobre o efeito da inanição em larvas de Sesarma curacaoense propôs que estas larvas apresentam comportamento lecitotrófico facultativo. No presente trabalho a morfologia do estômago de S. curacaoense foi estudada durante os estágios larvais, megalopa e juvenil I. A estrutura do estômago da zoea I possui cerdas específicas e com filtro pilórico aparentemente funcional. Especialização no estômago do zoea II (último estágio larval) foi evidenciada pelo incremento do número de cerdas na válvula cárdio-pilórica e pela complexidade do filtro pilórico. Após a metamorfose para o estágio megalopa, o estômago ficou consideravelmente complexo, com o aparecimento de um moinho gástrico contendo um medial e dois laterais dentes bem desenvolvidos. O estômago do juvenil I mostrou-se ainda mais especializado que no estágio anterior, exibindo características morfológicas similares àquelas descritas para decápodes adultos. Estes resultados corroboram o proposto em trabalhos anteriores, nos quais é indicado que S. curacaoense possui um desenvolvimento larval lecitotrófico facultativo.