Antimicrobial-Resistant Bacteria from Free-Living Green Turtles (Chelonia mydas)

Bioindicator species are used to assess the damage and magnitude of possible impacts of anthropic origin on the environment, such as the reckless consumption of antimicrobials. Chelonia mydas has several characteristics that make it a suitable bioindicator of marine pollution and of the presence of pathogens that cause diseases in humans. This study aimed to investigate the green sea turtle as a reservoir of resistant bacteria, mainly because C. mydas is the most frequent sea turtle species in Brazilian coastal regions and, consequently, under the intense impact of anthropic factors. Free-living green sea turtles ranging from 42.8 to 92 cm (average = 60.7 cm) were captured from Itaipú Beach, Brazil. Cloaca samples (characterizing the gastrointestinal tract) and neck samples (representing the transient microbiota) were collected. Bacterial species were identified, and their was resistance associated with the antimicrobials cephalothin, ciprofloxacin, gentamicin, tetracycline, and vancomycin. Citrobacter braaki, Klebsiella oxytoca, K. variicola and Proteus mirabilis were found resistant to cephalothin and Morganella morganii and Enterococcus faecalis tetracycline-resistant isolates in cloaca samples. In neck samples, species resistant to tetracycline were Salmonella sp., Serratia marcescens, S. ureylitica and Proteus mirabilis. This data reinforces that the green turtle is a bioindicator of antimicrobial resistance (AMR).

Microplastics in coastal and oceanic surface waters and their role as carriers of pollutants of emerging concern in marine organisms

Microplastics (Mps) pose a significant environmental challenge with global implications. To examine the effect of Mps on coastal and oceanic surface waters, as well as in marine organisms, 167 original research papers published between January 2013 and September 2022 were analyzed. The study revealed an unequal distribution of research efforts across the world. Fragments and fibers were the most frequently detected particles in ocean surface waters and marine biota, which mainly consisted of colored and transparent microparticles. Sampling of Mps was primarily done using collecting nets with a mesh size of 330 μm. Most articles used a stereomicroscope and Fourier-Transform Infrared spectroscopy for identification and composition determination, respectively. Polyethylene and polypropylene were the most frequent polymers found, both in coastal waters and in marine organisms. The major impact observed on marine organisms was a reduction in growth rate, an increase in mortality, and reduced food consumption. The hydrophobic nature of plastics encourages the formation of biofilms called the "plastisphere," which can carry pollutants that are often toxic and can enter the food chain. To better define management measures, it is necessary to standardize investigations that assess Mp pollution, considering not only the geomorphological and oceanographic features of each region but also the urban and industrial occupation of the studied marine environments.

The microbiome of the sponge Aplysina caissara in two sites with different levels of anthropogenic impact

Despite the important roles that marine sponges play in ecosystem functioning and structuring, little is known about how the sponge holobiont responds to local anthropogenic impacts. Here we assess the influence of an impacted environment (Praia Preta) on the microbial community associated with the endemic sponge Aplysina caissara in comparison to a less-impacted area (Praia do Guaecá) from the coast of São Paulo state (Brazil, southwestern Atlantic coast). We hypothesized that the local anthropogenic impacts will change the microbiome of A. caissara and that the community assembly will be driven by a different process (i.e. deterministic versus stochastic) under distinct levels of impact. The microbiome at the amplicon sequence variants level was found to be statistically distinct between sponges from the different sites, and this was also seen for the microbial communities of the surrounding seawater and sediments. Microbial communities of A. caissara from both sites were found to be assembled by deterministic processes, even though the sites presented distinct anthropogenic impacts, showing a pivotal role of the sponge host in selecting its own microbiome. Overall, this study revealed that local anthropogenic impacts altered the microbiome of A. caissara; however, assembly processes are largely determined by the sponge host.

Prokaryotic, Fungal, and Unicellular Eukaryotic Core Communities Across Three Sympatric Marine Sponges From the Southwestern Atlantic Coast Are Dominated Largely by Deterministic Assemblage Processes

Marine sponges are known to harbor a diverse and complex microbiota; however, a vast majority of surveys have been investigating the prokaryotic communities in the north hemisphere and Australia. In addition, the mechanisms of microbial community assembly are poorly understood in this pivotal player of the ecosystem. Thus, this survey addressed the holobiome of the sponge species in the São Paulo region (Brazil) for the first time and investigated the contribution of neutral and niche processes of prokaryotic, fungal, and unicellular eukaryotic assemblage in three sympatric species Aplysina caissara, Aplysina fulva, and Tedania ignis along with environmental samples. The compositions of the holobiome associated with the sponges and detected in environmental samples were strikingly different. Remarkably, between 47 and 88% of the assigned operational taxonomic units (OTUs) were specifically associated with sponge species. Moreover, around 77, 69, and 53% of the unclassified OTUs from prokaryotic, fungal, and unicellular eukaryotic communities, respectively, showed less than 97% similarity with well-known databases, suggesting that sponges from the southwestern Atlantic coast are an important source of microbial novelty. These values are even higher, around 80 and 61% of the unclassified OTUs, when excluding low abundance samples from fungal and unicellular eukaryotic datasets, respectively. Host species were the major driver shaping the sponge-associated microbial community. Deterministic processes were primarily responsible for the assembly of microbial communities in all sponge species, while neutral processes of prokaryotic and fungal community assembly were also detected in the sympatric A. caissara and T. ignis replicates, respectively. Most of the species-rich sponge-associated lineages from this region are also found in the Northern seas and many of them might play essential roles in the symbioses, such as biosynthesis of secondary metabolites that exhibit antimicrobial and antiviral activities, as well as provide protection against host predation. Overall, in this study the microbiota was assembled by interactions with the host sponge in a deterministic-based manner; closely related sponge species shared a strong phylogenetic signal in their associated prokaryotic and fungal community traits and Brazilian sponges were a reservoir of novel microbial species.

Community composition and functional prediction of prokaryotes associated with sympatric sponge species of southwestern Atlantic coast

Prokaryotes contribute to the health of marine sponges. However, there is lack of data on the assembly rules of sponge-associated prokaryotic communities, especially for those inhabiting biodiversity hotspots, such as ecoregions between tropical and warm temperate southwestern Atlantic waters. The sympatric species Aplysina caissara, Axinella corrugata, and Dragmacidon reticulatum were collected along with environmental samples from the north coast of São Paulo (Brazil). Overall, 64 prokaryotic phyla were detected; 51 were associated with sponge species, and the dominant were Proteobacteria, Bacteria (unclassified), Cyanobacteria, Crenarchaeota, and Chloroflexi. Around 64% and 89% of the unclassified operational taxonomical units (OTUs) associated with Brazilian sponge species showed a sequence similarity below 97%, with sequences in the Silva and NCBI Type Strain databases, respectively, indicating the presence of a large number of unidentified taxa. The prokaryotic communities were species-specific, ranging 56%-80% of the OTUs and distinct from the environmental samples. Fifty-four lineages were responsible for the differences detected among the categories. Functional prediction demonstrated that Ap. caissara was enriched for energy metabolism and biosynthesis of secondary metabolites, whereas D. reticulatum was enhanced for metabolism of terpenoids and polyketides, as well as xenobiotics' biodegradation and metabolism. This survey revealed a high level of novelty associated with Brazilian sponge species and that distinct members responsible from the differences among Brazilian sponge species could be correlated to the predicted functions.

Morphological and molecular systematics of the ‘Monanchora arbuscula complex’ (Poecilosclerida : Crambeidae), with the description of five new species and a biogeographic discussion of the genus in the Tropical Western Atlantic

Monanchora Carter, 1883 is a genus of shallow-water marine sponges comprising 16 species distributed worldwide, two of them in the Tropical Western Atlantic (TWA): M. arbuscula (Duchassaing & Michelotti, 1864) and M. brasiliensis Esteves, Lerner, Lôbo-Hajdu & Hajdu, 2012. The former species stands out as one of the most variable demosponges, and is very similar in spicule complement and in secondary metabolite chemistry to the Mediterranean/eastern Atlantic Crambe crambe (Schmidt, 1862), type species of Crambe Vosmaer, 1880. The aim of the present study was to revise the genus Monanchora in the TWA. In addition, we critically analyse the monophyly of Crambe and Monanchora. Maximum Likelihood and Bayesian Inference analyses of 28S and 16S rRNA sequences of the latter genera, and a redescription of the ‘M. arbuscula complex’, revealed three species: M. arbuscula s.s., M. coccinea, sp. nov. and a new species of Acarnidae – Iophon parvachela, sp. nov. Three other new species from the TWA previously assigned to Monanchora were revealed by morphological analyses, and are also described: M. bahamensis, sp. nov., M. megasigmifera, sp. nov. and a new species of Chondropsidae – Batzella catarinensis, sp. nov. A key for species identification is provided. Our results suggest that the Eastern Brazil and Southeastern Brazil Ecoregions may represent centres of diversity for Monanchora in the TWA.

Lissodendoryx (Ectyodoryx) Lundbeck, 1909 (Coelosphaeridae, Poecilosclerida, Demospongiae) from Southern Chile: new species and a discussion of morphologic characters in the subgenus

Our ongoing studies of the Chilean sponge fauna revealed four new species of Lissodendoryx (Ectyodoryx) that are described here, including three from the fjord's region (< 30 m depth, L.(E.) ballena sp. nov., L. (E.) corrugata sp. nov.,      L. (E.) coloanensis sp. nov.), and one from the deep waters off Diego Ramírez Archipelago (ca. 2000 m, L. (E.) diegoramirezensis sp. nov.). In addition, the type of L. (E.) anacantha was revised and found to bear much larger acanthostyles than originally reported. Our results revealed skeletal architectures quite distinct from that reported from the type species of L. (Ectyodoryx), and not predicted in the current diagnosis of Lissodendoryx, requiring an amended diagnosis. Ectosomal megascleres also set the majority of the new species apart from the type species of L. (Ectyodoryx), which does not have terminally microspined (sub)tylotes. This character is widespread in Lissodendoryx and might be pointing to phylogenetic affinities across the current subgeneric arrangement. Further morphologic characters and alternative phylogenetic scenarios are discussed, including hymedesmiid and myxillid affinities of the species described here.

Twelve new Demospongiae (Porifera) from Chilean fjords, with remarks upon sponge-derived biogeographic compartments in the SE Pacific

This article reports on 12 new species originating from the Chilean fjords region, namely Clathria (Microciona) mytilifila sp. nov., Haliclona (Reniera) caduca sp. nov., Latrunculia (L.) ciruela sp. nov., Latrunculia (L.) copihuensis sp. nov., Latrunculia (L.) verenae sp. nov., Latrunculia (L.) yepayek sp. nov., Myxilla (Burtonanchora) araucana sp. nov., Neopodospongia tupecomareni sp. nov., Oceanapia guaiteca sp. nov., Oceanapia spinisphaera sp. nov., Suberites cranium sp. nov. and Tethya melinka sp. nov. The material studied was collected between 5 and 30 m depth at latitudes comprised between 42º and 50ºS, and is part of a large collection of Chilean sponges gathered by an international team in a series of expeditions. Identification keys are provided for SE Pacific Suberites and Latrunculia, and the known species of Myxilla (Burtonanchora) and Neopodospongia. A trans-Pacific link to the New Zealand fauna was retrieved for the latter genus. Distribution ranges apparent from the materials studied here are judged too preliminary to allow any inference on biotic boundaries in the SE Pacific. A revision of earlier assertions about these biogeographic units and their boundaries concluded that very little support remains other than for existence of a Magellanic fauna. This is in part a consequence of revising the taxonomy of sponge species originally deemed to underpin these areas. Specifically, the former proposal of a Central to Southern Chile biogeographic unit (33-56ºS) has been markedly undone. 

Mycalina: another crack in the Poecilosclerida framework

This is the first phylogenetic analysis integrating both morphological and molecular data of the sponge suborder Mycalina (Poecilosclerida), which was erected in 1994. A cladistic analysis of morphology supported the monophyly of Cladorhizidae (including Euchelipluma), Guitarridae (excluding Euchelipluma), Isodictyidae, Latrunculiidae, and Podospongiidae but rejected monophyly for Desmacellidae, Esperiopsidae, Hamacanthidae, and Mycalidae. Analyses of partial 16S and partial 28S rRNA datasets combined, as well as that of a complete 18S rDNA dataset, suggest that Mycalina is not monophyletic; Biemnidae is only distantly related to other poecilosclerids; Merlia and Desmacella branch near the base of a diverse Poecilosclerida clade; Mycalidae is monophyletic (excluding Mycale [Anomomycale] titubans in 18S); and Esperiopsidae and Isodictyidae form a clade. Analyses of the two molecular datasets differed on the monophyly of Podospongiidae and about the relationship of Podospongiidae to Isodictyidae + Esperiopsidae.

Nuclear markers reveal a complex introgression pattern among marine turtle species on the Brazilian coast

Surprisingly, a high frequency of interspecific sea turtle hybrids has been previously recorded in a nesting site along a short stretch of the Brazilian coast. Mitochondrial DNA data indicated that as much as 43% of the females identified as Eretmochelys imbricata are hybrids in this area (Bahia State of Brazil). It is a remarkable find, because most of the nesting sites surveyed worldwide, including some in northern Brazil, presents no hybrids, and rare Caribbean sites present no more than 2% of hybrids. Thus, a detailed understanding of the hybridization process is needed to evaluate natural or anthropogenic causes of this regional phenomenon in Brazil, which could be an important factor affecting the conservation of this population. We analysed a set of 12 nuclear markers to investigate the pattern of hybridization involving three species of sea turtles: hawksbill (E. imbricata), loggerhead (Caretta caretta) and olive ridley (Lepidochelys olivacea). Our data indicate that most of the individuals in the crossings L. olivacea × E. imbricata and L. olivacea × C. caretta are F1 hybrids, whereas C. caretta × E. imbricata crossings present F1 and backcrosses with both parental species. In addition, the C. caretta × E. imbricata hybridization seems to be gender and species biased, and we also found one individual with evidence of multispecies hybridization among C. caretta × E. imbricata × Chelonia mydas. The overall results also indicate that hybridization in this area is a recent phenomenon, spanning at least two generations or ~40 years.

Isolation and cultivation of fungal strains from in vitro cell cultures of two marine sponges (Porifera: Halichondrida and Haplosclerida)

Despite the large number of reports describing sponge-microbe associations, limited knowledge is available about associated fungi and their relationships with the hosts. In this work, specific fungal strains were obtained directly from in vitro sponge cell cultures (primmorphs) and single sponge cells (cytospins) and compared with those obtained from whole tissue preparations. A total of 27 fungal strains were isolated from the marine sponges Hymeniacidon heliophila and Haliclona melana. Fifteen strains, nine from H. heliophila and six from H. melana, were obtained from whole tissue and were considered as possible mesohyl associated or transient fungi. Twelve strains were isolated from in vitro sponge cell cultures (primmorphs) and were, therefore, considered as cell associated. From these, five different strains were obtained from H. heliophila isolated cells, while five were identified from cytospins and two from primmorphs of H. melana. The fungal strains obtained from cell cultures from both sponge species were different, and none of them were detected in the whole tissue preparations of the same species. Nine H. heliophila and seven H. melana strains shows low similarity with the sequences available in public databases and belong to potentially new species. This is the first report of fungi isolated directly from sponge cells, which allowed the observation and selection of specific strains that probably would not be obtained by usual culture dependent techniques.

Sex determination in Turdus amaurochalinus (Passeriformes: Muscicapidae): morphometrical analysis supported by CHD gene

Sex determination is important for conservation and population studies, particularly for reproduction programs of threatened species and behavioural ecology. Turdus amaurochalinus, Creamy-bellied Thrush, only exhibits sexual dimorphism during the breeding season, when males are considered to show intense yellow bills, and females and immature males show dark brown bills. The objectives of this study were: 1) to determine the sex of individuals using genetic techniques, and 2) to test the hypothesis that sex dimorphism can be detected by morphometry. This study was carried out at Parque Nacional da Restinga de Jurubatiba, a preserved area located on the North coast of Rio de Janeiro State. The birds were captured using ornithological nets, singly marked with metal rings, weighed, measured and had blood samples collected before being released. The sex of 42 T. amaurochalinus individuals was determined using the CHD gene marker. A total of 20 males and 22 females were identified from June to August, with peak capture frequency in June. Turdus amaurochalinus females and males differed significantly in morphometrical measures. The most important traits to distinguish males from females were wing length (Student t-test = 4.34, df = 40, p = 0.0001) and weight (Student t-test = 2.08, d f = 40, p = 0.044): females were heavier and had significantly shorter wing length than males. Females and males were correctly classified in 86% and 75% of cases, respectively, using Discriminant Analysis. The molecular analysis was the most secure method for sex determination in the studied species.

Detection of polymorphisms of the mtDNA control region of Caretta caretta (Testudines: Cheloniidae) by PCR-SSCP

Marine turtles are increasingly being threatened worldwide by anthropogenic activities. Better understanding of their life cycle, behavior and population structure is imperative for the design of adequate conservation strategies. The mtDNA control region is a fast-evolving matrilineal marker that has been employed in the study of marine turtle populations. We developed and tested a simple molecular tracing system for Caretta caretta mtDNA haplotypes by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP). Using this technique, we were able to distinguish the SSCP patterns of 18 individuals of the haplotypes CC-A4, CC-A24 and CCxLO, which are commonly found in turtles sampled on the Brazilian coast. When we analyzed 15 turtles with previously unknown sequences, we detected two other haplotypes, in addition to the other four. Based on DNA sequencing, they were identified as the CC-A17 and CC-A1 haplotypes. Further analyses were made with the sea turtles, Chelonia mydas (N = 8), Lepidochelys olivacea (N = 3) and Eretmochelys imbricata (N = 1), demonstrating that the PCR-SSCP technique is able to distinguish intra- and interspecific variation in the family Cheloniidae. We found that this technique can be useful for identifying sea turtle mtDNA haplotypes, reducing the need for sequencing.

Molecular diversity of disintegrin-like domains within metalloproteinase precursors of Bothrops jararaca

Disintegrins are small peptides isolated from the venom of several snake families which act as integrin-antagonists or agonists, interacting with a variety of biological processes mediated by integrins. In this work we describe five new disintegrin-like domains within metalloproteinase precursor sequences, obtained from a Bothrops jararaca venom gland cDNA library. Among the new disintegrin-like domains, four were contained in PIII metalloproteinase precursors, with three of them presenting ECD-motifs and one presenting a new KCD-motif. Moreover, we found three disintegrin-like domains within PII metalloproteinase precursors. Two of them are similar to the already described disintegrins jarastatin and jararacin. The third molecule is unusual, presenting some typical PIII metalloproteinase characteristics but lacking the cysteine-rich domain being, thus, classified as a PII metalloproteinase. Only few reports presented molecules with these characteristics. Sequence analysis suggests that these molecules are intermediate steps between the more ancient PIII and the more recent PII metalloproteinases. We also investigated disintegrin N-terminus diversity in B. jararaca crude venom by purifying jarastatin and jararacin and analyzing them by mass spectrometry.