Relative abundance of euphausiids (Crustacea) in water samples of the Arabian Sea (Table 2)

In the present paper, the ecology and feeding habits of euphausiids are described. The samples were taken at the time of the NE-monsoon (1964/65) by R. V. "Meteor" in the Arabian Sea and adjacent waters. 24 species were determined. According to distribution of the species, the following marine areas can be distinguished: Arabian Sea: 24 species, dominant are Euphausia diomedeae, E. tenera, E. distinguenda, Stylocheiron carinatum. Gulf of Aden: 10 species, dominant are Euphausia diomedeae, E. distinguenda. Red Sea: 6 species, dominant are Euphausia diomedeae, E. distinguenda. Gulf of Oman : 5 Species, dominant are Euphausia distinguenda, Pseudeupbaufia latifrons. Persian Gulf: 1 species - Pseudeuphausia latifrons. The total number of euphausiids indicate the biomass of this group. High densities of euphausiids (200-299 and > 300 individuals/100 m**3) occur in the innermost part of the Gulf cf Aden, in the area south of the equator near the African east coast, near Karachi (Indian west coast) and in the Persian Gulf. Comparison with data relating to production biology confirms that these are eutrophic zones which coincide with areas in which upwelling occurs at the time of the NE-monsoon. The central part of the Arabian Sea differs from adjacent waters by virtue of less dense euphausiid populations (> 199 individuals/100 m**3). Measurements relating to production biology demonstrate a relatively low concentration of primary food sources. Food material was ascertained by analysis of stomach content. The following omnivorous species were examined: Euphausia diomedeae, E. distinguenda, E. tenera, Pseudeuphausia latifrons and Thysanopoda tricuspidata. Apart from crustacean remains large numbers of Foraminifera, Radiolaria, tintinnids, dinoflagellates were found in the stomachs. Quantitatively crustaceans form the most important item in the diet. Food selection on the basis of size and form appears to be restricted to certain genera of tintinnids. The genera Stylocheiron and Nematoscelis are predators. Only crustacean remains were found in the stomachs of Stylocheiron abbreviatum, whereas Radiolaria, Foraminifera and tintinnids occurred to some extent in Nematasceli sp. Different euphausiids in the food chain in the Arabian Sea. In omnivorous species the position is variable, since they not only feed by filtering autotrophic and heterotrophic Protista, but also by predation on zooplankton. Carnivorous species without filtering apparatus feed exclusively on zooplankton of the size of copepods. Only these species are well established as occupying a higher position in the food chain. The parasitic protozoan Tbalassomyces fagei was found on Euphausia diomedeae, E. fenera, E. distinguenda and E. sanzoi.

Fossil associations from the middle and upper Eocene strata of the Pamplona Basin and surrounding areas (Navarre, western Pyrenees)

Fossil associations from the middle and upper Eocene (Bartonian and Priabonian) sedimentary succession of the Pamplona Basin are described. This succession was accumulated in the western part of the South Pyrenean peripheral foreland basin and extends from deep-marine turbiditic (Ezkaba Sandstone Formation) to deltaic (Pamplona Marl, Ardanatz Sandstone and Ilundain Marl formations) and marginal marine deposits (Gendulain Formation). The micropalaeontological content is high. It is dominated by foraminifera, and common ostracods and other microfossils are also present. The fossil ichnoasssemblages include at least 23 ichnogenera and 28 ichnospecies indicative of Nereites, Cruziana, Glossifungites and ?Scoyenia-Mermia ichnofacies. Body macrofossils of 78 taxa corresponding to macroforaminifera, sponges, corals, bryozoans, brachiopods, annelids, molluscs, arthropods, echinoderms and vertebrates have been identified. Both the number of ichnotaxa and of species (e. g. bryozoans, molluscs and condrichthyans) may be considerably higher. Body fossil assemblages are comparable to those from the Eocene of the Nord Pyrenean area (Basque Coast), and also to those from the Eocene of the west-central and eastern part of South Pyrenean area (Aragon and Catalonia). At the European scale, the molluscs assemblages seem endemic from the Pyrenean area, although several Tethyan (Italy and Alps) and Northern elements (Paris basin and Normandy) have been recorded. Palaeontological data of studied sedimentary units fit well with the shallowing process that throughout the middle and late Eocene occurs in the area, according to the sedimentological and stratigraphical data.

Electric shock causes physiological stress responses in shore crabs, consistent with prediction of pain

Animal pain is defined by a series of expectations or criteria, one of which is that there should be a physiological stress response associated with noxious stimuli. While crustacean stress responses have been demonstrated they are typically preceded by escape behaviour and thus the physiological change might be attributed to the behaviour rather than a pain experience. We found higher levels of stress as measured by lactate in shore crabs exposed to brief electric shock than non-shocked controls. However, shocked crabs showed more vigorous behaviour than controls. We then matched crabs with the same level of behaviour and still found that shocked crabs had stronger stress response compared with controls. The finding of the stress response, coupled with previous findings of long-Term motivational change and avoidance learning, fulfils the criteria expected of a pain experience.

Qualidade dos empregos e a carcinicultura marinha nos laboratórios da praia de Barreta/RN

To present research had for objective to study the quality of the employment in the maturation Laboratories and larviculture of the Beach of Barreta/RN, adopting for so much the criteria used by Reinecke(1999) to characterize a quality employment: surrender, benefits non salary, regularity and work reliability and of the wage, contractual status, social protection, work day, intensity of the work, risk of accidents and of occupational diseases, involvement in linked decisions to the section work, possibility for the development of professional qualifications. Of the exam of the data it was verified that the generated employments are considered employments of good quality. However, this result should be analyzed to the light of a context of extreme informality and of precarization of the work. Therefore, the results should be relativized. He/she/you imports to retain that one of the limitations of the study resides in the impossibility of generalizing the data for the whole section of the sea carcinicultura. In spite of that fact, he/she is considered that the objectives of the research were assisted fully and that the characterization of the profile of the employment generated by the section of the shrimpculture it is extremely important for the drawing of public politics gone back to foment this activity.

Tributos indiretos na cadeia produtiva do camarão

The state of Rio Grande do Norte counts with a relevant potential in the shrimp farming supply chain. In the larviculture step the state responds for more than half of the national production. In the farming step it is the second largest producer. In the industrial step, its industries have almost 40% of the shrimp processing capacity of the northeast of Brazil. However, this country has the highest tax rate comparing with the main shrimp producer countries. Considering the influence of taxes in the competition among companies, the main goal of this research is to analyze the impact of indirect taxes in the above steps of the supply chain. To achieve it, it will be used the data of the 2011 Census of the Shrimp Farming and it will be applied the Herfindahl-Hirschman Index to identify the market form of those steps. In order to contribute with the characterization of the supply chain, CEO´s of farms and industries will be interviewed. The price-elasticity of the shrimp larvae, the in natura shrimp and the processed shrimp will be analyzed in order to verify the possibility that each one of those three steps has to pass-through the onus of the end of benefit over the ICMS. The data analysis shows that the larviculture step functions as a duopoly and, facing the end of that benefit, it will be able to pass-through most its onus to the farming step. On the other hand, this step functions similar to a perfect competing market, which diminishes its capacity to pass-through that onus to the processing step. This step operates as oligopoly with a lower concentration than the larviculture step but, due to the fact that it faces an oligopsony, it will end up assuming most of that onus, which will cause a decrease in the amount of processed shrimp. It is concluded that the end of that benefit would impact negatively, in this state, the supply chain at all, but mainly the farming and the industrial steps

Evaluation of molecular weight of Chitosan in thin-layer and spouted bed drying

Chitosan is chitin in deacetylated form and is the main constituent of crustacean exoskeletons. Commercially, chitosan is dried in tray driers, and during the operation, polymerization may occur as the chitosan is composed of carbohydrates. The aim of this work was to analyze chitosan in spouted bed and thin-layer drying, considering viscosity average molecular weight of the chitosan samples in the process. Results showed that spouted bed-dried chitosan presented a molecular weight value similar (160 kDa) to that of the raw one (150 kDa). However, when dried on tray dryers, the molecular weight was 300 kDa, indicating that molecule polymerization occurred.

Evaluation of molar weight and deacetylation degree of chitosan during chitin deacetylation reaction: Used to produce biofilm

Chitosan is a polysaccharide derived from chitin, mainly of crustacean shells and shrimp wastes. The utilization of chitosan is related to the molar weight and deacetylation degree of the biopolymer. The aim of this work is to study the chitin deacetylation reaction, by the viscosity average molar weight and deacetylation degree of chitosan as a function of reaction time. Deacetylation was carried out in concentrated alkaline solution, 421 g L−1, at 130◦C and the reaction occurred during 4 h. Chitosan paste obtained after 20, 90 and 240 min was used to produce biofilms, which were characterized according water vapor permeability and mechanical properties (tensile strength and percentage tensile elongation at break). During the reaction time deacetylation degree reached 93%, and a 50% reduction in the viscosity average molar weight value in relation to the value of the first 20 min of reaction was found Both reactions presented a kinetic behavior of the pseudo-first order. Biofilm produced from the paste of chitosan with high deacetylation degree showed higher water vapor permeability (WVP), tensile strength (TS) and elongation (E) when compared to films with a low deacetylation.

Genetic effect of domestication selective pressures on Pacific oyster at larval stage

Among bivalve species, the Pacific oyster, Crassostrea gigas, is the most economically important bivalve production over the world. Today, C. gigas is subject to an important production effort that leads to an intensive artificial selection. Larval stage is relatively unknown, specifically in a domestication context. Genetic consequence of artificial selection is still at a preliminary study. We aimed to tackle the consequence of inconscient domestication on the variance reproductive success focusing on larval stage, keystone of the life cycle. We studied two kinds of specific selective processes that common hatchery rearing practices exert : the effect of discarding the smallest larvae on genetic diversity and the artificial environment rearing effect via the temperature providing a contrast resembling wild versus hatchery conditions (20 and 26°C). In order to monitor the effect of the selection of fast growing larvae by sieving, growth variability and genetic diversity in a larval population descended from a factorial breeding was studied. We used a mixed-family approach to reduce potentially confounding environmental biais. The retrospective assignment of individuals to family groups has been performed using a three microsatellite markers set. Two different rearing were carried out in parallel. For three (replicates) 50-l tanks, the smallest larvae were progressively discarded by selective sieving, whereas for the three others no selective sieving was performed. The intensity of selective sieving was adjusted so as to discard 50% of the larvae over the whole rearing period in a progressive manner. As soon as the larvae reached the pediveliger stage, ready to settle larvae were sampled for genetic analysis. Regarding the artificial environment rearing effect via the temperature, we used a similar mixed-family approach. The progeny from a factorial breeding design was divided as follows: three (replicates) 50-l tanks were dedicaced to a rearing at 26°C versus 20°C for three others 50-l tanks. The whole size variability was preserved for this experiment. Individual growth measurements for larvae genetically identified have been performed at days 22 and 30 after fertilization for both conditions. In a same way, we collected individual measurements for genotyped juvenile oysters (80 days after fertilization). At a phenotypic scale, relative survival and settlement success for larvae with sieving were higher. Sieving appears as a time-saving process associated with a better relative survival ratio. But in the same time, our results confirm that a significant genetic variability exist for early developmental traits in the Pacific oyster. This is congruent with the results already obtained that investigated genetic variability and genetic correlations in early life-history traits of Crassostrea gigas. Discarding around 50% of the smallest larvae can lead to significant selection at the larval stage.

Ecological health analysis of Caspian marine environment based on the diversity and distribution pattern of meiofauna in the Mazandaran Province, Caspian Sea

Biodiversity and distribution of benthic meiofauna in the sediments of the Southern Caspian Sea (Mazandaran) was studied in order to introducing and determining of their relationship with the environmental factors. From 12 stations (ranging in depths 5, 10, 20 and 50 meters), sediment samples were gathered in 6 months (2012). Environmental factors of water near the bottom including temperature, salinity, dissolved oxygen and pH were measured during sampling with CTD and grain size and total organic matter percentage and calcium carbonate were measured in laboratory. In different months, the average water temperature (9.52-23.93), dissolved oxygen (7.71-10.53 mg/L), salinity (10.57±0/07 and 10.75±0/04 ppt), pH (7.44±0/29 and 7.41±0/22), EC (17.97±0/12 and 18.30±0/04μs/cm2), TDS (8.92±0/04 and 9.14±0/02 mg/L), total organic matter (5.83±1/43 and 6.25±0/97%) and calcium carbonate (2.36±0/36 and 1.68±0/19%) were measured respectively. Structure of the sediment samples mostly consisted of fine sand; very fine sand, silt and clay. From the 4 group animals (Foraminifera, Crustacea, Worms and Mollusca), there were identified 40species belong to 29 genera of 25 families. The cosmopolitan foraminifer, Ammonia beccarii caspica, was common in all sampling stations. Result showed that depth was important factor on distribution of meiofauna. Most density of foraminifera and crustacean was observed in depth of 20m and for mollusca and worms observed in 5m. Shannon diversity index decreased with depth that showed in shallow water diversity was higher than deep water. Mean of maximum and minimum Shannon index was obsorvers in depth of 5m and 50 m that was measured in order 0.93 and 0.43. Account of Shannon index showed that this area is under pressure. Account of peioleo index showed distribution in this area was not steady.

Quitosana na indução de resistência ao tombamento de plântulas de espécies olerícolas e no controle de fitopatógenos in vitro

Induction of resistance is defined as the activation of a state of resistance against diseases which is induced systemically in plants by the use of biotic or abiotic agents without any modification of the plant genome, occurring non-specific way, by activating genes coding for various plant defense responses. Chitosan is a polymer derived from the deacetylation of chitin, which is found in large quantities in crustacean shell, and studied with the potential to control plant pathogens, both by its direct fungistatic action, as the ability to induce protection of plants, indicating the presence of molecules of elicitoras characteristics. Three experiments with objective of evaluating the potential of chitosan in the seedling resistance induction were developed, beet (Beta vulgaris) seeds, cucumber (Cucumis sativus) seeds and tomato (Solanum lycopersicum) seeds, and the control of Fusarium sp., Rhizoctonia solani K¨uhn e Pythium sp. in vitro conditions. The experimental design was completely randomized, with four replications. Beet seeds, tomato and cucumber were submerged in chitosan solution for 20 minutes, in concentrations of 0.25, 0.5, 1 and 2% in the control and distilled water. Seeds were sown in trays containing Plantmax Florestalr substrate sterilized and inoculated with Fusarium sp., Rhizoctonia solani K¨unh and Pythium sp., respectively for the three cultures. The experiment was conducted for 14 days in growth chamber with controlled temperature (25 C 2 C), light (12 hour photoperiod) and humidity (70% 10%). The evaluations were seed emergency, seedling damping-off, seedling length, fresh weight and activity of the enzymes phenylalanine amˆonia-liase (PAL), chitinase and b-1,3-glucanase. It was also rated the mycelial growth of Fusarium sp., Pythium sp. and R. solani on P.D.A. (Potato-Dextrose and Agar) culture medium containing chitosan at the same concentrations evaluated in seeds. For beet growing, seed treatment with chitosan presented higher emergence and the length of the seedlings, and reduced the percentage of tipping. Treatment with chitosan activated the systemic acquired resistance with expression of chitinase and b-1,3-glucanase enzymes. For the tomato crop in chitosan concentration of 0.25% favored the emergency of seedlings, reduced the incidence of tipping and activated the PAL enzymes, chitinase and b-1,3-glucanase. In cucumber on the concentration of up 0.5% favored seedlings emergence and reduces the incidence of tipping. Chitosan activated the PAL enzymes and b-1,3-glucanase. Chitosan also presented fungistatic action on the initial growth of Pythium sp. and R. solani in vitro conditions, however, such action did not prevail until the end of the experiment. To Fusarium sp. the concentration of chitosan resulted in the reduction of mycelial growth in vitro.

Studies on Mahshahr Creeks macrobenthos with emphasis on their importance in fish feeding

To study the macrobenthic community at Mahshahr creek four Creeks namely Bihad, Doragh, Ghazaleh and Ghanam were chosen. Sampling was conducted on bimonthly basis and carried out from August 1996 to June 1997, 216 sediment samples were collected from 12 stations using 0.1 m^2 Van Veen Grab, The stations were located at the mouth, middle and the end of each Creek. In situ measurements of temperature pH, DO and salinity were done using different sensors. The samples for the measurements of TOM, grain size were collected and analysed in vitro. The results indicate spatial and temporal heterogeneity in the structure of macro faunal assemblages of the creeks. A total of 12 macrofaunal groups were identified within the study area. Amphipods were the most dominant group (43%) followed by polychaetes (42%), copepods (3.5%), tanaids (3.1%) and other groups (8.4%). The range for the numerical abundance of macrobenthos was between 12583 to 3648 individual per m2 and the variation was done to different bottom texture the variable environment conditions governing the different parts of each creek as well as within creeks. Application of diversity indices (Shannon H and Simpson indices) on the dominant macrobenthic assemblages (crustaceans & polychaetes) was varied between 1 to 2.5 being higher in Bihad and Ghanarn and much reduced Shannon H index or a higher Simpson in Ghazaleh. Probably brought about activities in this creek. Gut content analysis of four species of fish showed that the main food items consist of Crab, Shrimps and other crustacean species, The secondary production of macrobenthic fauna and hence a fish production were assessed. To do this first the production of most dominant species Apseudes sp. was computed through Cohort analysis. The total macrobenthic production was estimated and from this fish production was computed. The macrobenthic and fish secondary productions were 24300 tons/year) and 24300 (tons/year) respectively. These values were lower than those with similar areas in the Indian Ocean.

Investigation on reproduction process in two species of crab Eriphia sebana and Ocypode saratan in the intertidal zone of Chabahar area

The present study with headline investigation on reproduction in two species of Crab Eriphia sebana and Ocypode saratan was carried out in the intertidal zone of Chabahar in thirteen month from December 2004 to December 2005. Checked samplings have been taken, 45 number Crab monthly from any four stations by manual or use trap. During this study the following subjects were measured: Temperature range and salinity, Measurable coast granule, Determination of sex ratio, Relations carapace width with carapace length, Carapace width with total body weight, Gonad weight, gonadosomatic index, condition factor, gastrosomatic index, investigation content in stomach, LM50, Growth parameters, plenty distribution length and width and gonad weight and total body weight. Studied on measurable coast granule were expressed that Ocypode saratan in Desalination station, were nest in soils equable sand and this quantity were confirmed in Pozm station. Sex ratio were assign in desalination area and Pozm M: F 0/44:0/56 and in Tiss and Chabahar M: F 0/45:0/55. Carapace length and carapace width (cm) and body weight (g) Furthest were designated in Ocypode saratan within carapace width sequential: female: 5/42-6/15-105/13 and male: 5/53-6/25-108/91 and in Eriphia sebana within Tiss area sequential: female: 5/12-5/94-110/21 and male 5/14-60/01-114/37. Have been linear relationship between carapace length and carapace width and equaled CW = a CL + b. Weight growth in two species were be modal and equaled BW= aCLb and increased Crab weight by built up carapace width. Maximum gonad weight in Ocypode saratan within desalination area in female have been outcome 3/39 and in male 0/84g and in Eriphia sebana extreme within Tiss during may in female were be 4/18 and in male 1/1g. Stomach content in Eriphia sebana were involved a black until half-purplish liquid and yellowish in Ocypode saratan. Stomach contents identifiable were being in four groups: Molluscoid, Crustacean, Plankton and Fish. Carapace width during the first year of maturation have been LM50:3/77 in Desalination area and LM50:3/92 in Pozm for Ocypode saratan and LM50:4/26 in Tiss and LM50:4/62 in Chabahar. Ability spawning in Eriphia sebana within Tiss has been CW=4/17cm and in Ocypode saratan within Desalination area CW=4/23cm. Maximun value of Loo for Eriphia sebana was equal 59/67 and growth factor K=0/68 within Tiss and Loo =61/64 , K=0/65 for Ocypode saratan within Desalination area. Maximun GSI and GI have been within Desalination area and Tiss and minimum within Pozm and Chabahar. The maturity stages of two species were classifed into six stages. Review on GSI, CF have been showed that relation with temperature and salinity and definer in two species have been spawned in two period that Maximun in spring premier than autumn.

Development of a simple and fast “DNA extraction kit” for sea food identification and marine species

Seafood products fraud, the misrepresentation of them, have been discovered all around the world in different forms as false labeling, species substitution, short-weighting or over glazing in order to hide the correct identity, origin or weight of the seafood products. Due to the value of seafood products such as canned tuna, swordfish or grouper, these species are the subject of the commercial fraud is mainly there placement of valuable species with other little or no value species. A similar situation occurs with the shelled shrimp or shellfish that are reduced into pieces for the commercialization. Food fraud by species substitution is an emerging risk given the increasingly global food supply chain and the potential food safety issues. Economic food fraud is committed when food is deliberately placed on the market, for financial gain deceiving consumers (Woolfe, M. & Primrose, S. 2004). As a result of the increased demand and the globalization of the seafood supply, more fish species are encountered in the market. In this scenary, it becomes essential to unequivocally identify the species. The traditional taxonomy, based primarily on identification keys of species, has shown a number of limitations in the use of the distinctive features in many animal taxa, amplified when fish, crustacean or shellfish are commercially transformed. Many fish species show a similar texture, thus the certification of fish products is particularly important when fishes have undergone procedures which affect the overall anatomical structure, such as heading, slicing or filleting (Marko et al., 2004). The absence of morphological traits, a main characteristic usually used to identify animal species, represents a challenge and molecular identification methods are required. Among them, DNA-based methods are more frequently employed for food authentication (Lockley & Bardsley, 2000). In addition to food authentication and traceability, studies of taxonomy, population and conservation genetics as well as analysis of dietary habits and prey selection, also rely on genetic analyses including the DNA barcoding technology (Arroyave & Stiassny, 2014; Galimberti et al., 2013; Mafra, Ferreira, & Oliveira, 2008; Nicolé et al., 2012; Rasmussen & Morrissey, 2008), consisting in PCR amplification and sequencing of a COI mitochondrial gene specific region. The system proposed by P. Hebert et al. (2003) locates inside the mitochondrial COI gene (cytochrome oxidase subunit I) the bioidentification system useful in taxonomic identification of species (Lo Brutto et al., 2007). The COI region, used for genetic identification - DNA barcode - is short enough to allow, with the current technology, to decode sequence (the pairs of nucleotide bases) in a single step. Despite, this region only represents a tiny fraction of the mitochondrial DNA content in each cell, the COI region has sufficient variability to distinguish the majority of species among them (Biondo et al. 2016). This technique has been already employed to address the demand of assessing the actual identity and/or provenance of marketed products, as well as to unmask mislabelling and fraudulent substitutions, difficult to detect especially in manufactured seafood (Barbuto et al., 2010; Galimberti et al., 2013; Filonzi, Chiesa, Vaghi, & Nonnis Marzano, 2010). Nowadays,the research concerns the use of genetic markers to identify not only the species and/or varieties of fish, but also to identify molecular characters able to trace the origin and to provide an effective control tool forproducers and consumers as a supply chain in agreementwith local regulations.

An intimate link between antimicrobial peptide sequence diversity and binding to essential components of bacterial membranes

Antimicrobial peptides and proteins (AMPs) are widespread in the living kingdom. They are key effectors of defense reactions and mediators of competitions between organisms. They are often cationic and amphiphilic, which favors their interactions with the anionic membranes of microorganisms. Several AMP families do not directly alter membrane integrity but rather target conserved components of the bacterial membranes in a process that provides them with potent and specific antimicrobial activities. Thus, lipopolysaccharides (LPS), lipoteichoic acids (LTA) or the peptidoglycan precursor Lipid II are targeted by a broad series of AMPs. Studying the functional diversity of immune effectors tells us about the essential residues involved in AMP mechanism of action. Marine invertebrates have been found to produce a remarkable diversity of AMPs. Molluscan defensins and crustacean anti-LPS factors (ALF) are diverse in terms of amino acid sequence and show contrasted phenotypes in terms of antimicrobial activity. Their activity is directed essentially against Gram-positive or Gram-negative bacteria due their specific interactions with Lipid II or Lipid A, respectively. Through those interesting examples, we discuss here how sequence diversity generated throughout evolution informs us on residues required for essential molecular interaction at the bacterial membranes and subsequent antibacterial activity. Through the analysis of molecular variants having lost antibacterial activity or shaped novel functions, we also discuss the molecular bases of functional divergence in AMPs.

Projeto raia de fogo: aspectos populacionais da raia de fogo (Dasyatis marianae Gomes, Rosa & Gadig, 2000) e pesca de elasmobrânquios no complexo recifal do Parracho de Maracajaú

The species Dasyatis marianae inhabits coastal areas associated with coral reefs, considered endemic to the northeast of Brazil, occurring from the State of Maranhão to the south of Bahia. Specimens of this species are commonly sighted by divers and fishermen in the area of Maracajaú reefs, a complex reef that is part of the Environmental Protection Area of Coral Reefs (EPACR), which was developed in this study about the ecology and biology of the D. marianae, in order to characterize aspects of population structure in the area of the reef complex of Parracho de Maracajaú. We analyzed 120 specimens caught by artisanal fishing site of the size, weight, sex, stage of maturity and stomach contents. Most subjects were adult males (1.7:1) and was more abundant for rays with lengths between 25 and 29cm of LD, where females reach larger sizes, a feature common to other rays. The largest specimens were captured in the area of seagrass, which is preferred for the species. The distribution of species in the area showed an ontogenetic and sexual segregation, where the youthful occur near the beach, which is a likely area for nursery and growth of the adult females prevail in the seagrass, which apparently has a high prey availability, and Adult males are more distant, a higher proportion occurring in outlying areas, suggesting a habit more exploratory than the females. The evaluation of the reproductive system indicated 3 reproductive cycles per year, one young per pregnancy, and showed that the mature males were smaller than females. The cubs of D. marianae size at birth 12 to 15cm LD. As for diet, the species was characterized as carnivorous crustacean specialist. The performance of visual censuses in different localities allowed to evaluate the density of D. marianae in different environments of the complex. The species occurs in greater numbers in seagrass, environment very important for the conservation of the species. 100 individuals of D. marianae marked in reef complex area enrolled in a recapture rate of 3%. Some behavioral aspects were evaluated, as diurnal pattern of activity, interaction with cleaning and fish Pomacanthus paru followers as Lutjanus analis and Carangoides bartholomaei. Overall, much of the information obtained should be used for management of the species