The purpose of this study was to find an alternative instrumental method to sensory analysis and to further investigate the aroma properties of spoiling blue crab meat. This was accomplished by use of a Cyranose 320™ Electronic Nose, Draeger-Tubes®, and solid-phase microextraction gas chromatography-mass spectrometry (SPME-GC-MS). These techniques were compared to the more established techniques for determining quality of blue crab meat of sensory and microbiological analysis. Three different electronic nose methods were used to evaluate five sequentially spoiled groups of crab meat. The manufacturer's recommended setup only resulted in a 30 % correct separation of the known groups, and only 10 % of the samples were correctly identified when coded unknown samples were used to validate the electronic nose training results. The compressed air method which utilized compressed tank breathing air, filtered through activated carbon and moisture traps resulted in 100 % separation of the known groups, but only correctly identified 20 % of the coded unknown samples. Draeger-Tubes® were found to be more accurate and precise compared with the electronic nose. All 5 groups of samples analyzed using Draeger-Tubes® were found to be significantly different at α = 0.05 using a Tukey-Kramer ANOVA statistical procedure. The coded unknown samples were correctly identified at a rate of 83 %. The simplicity and rapidness of this procedure allows it to possibly be an alternative for the crab industry as an alternative to sensory analysis. SPME-GC-MS found trimethylamine (TMA), ammonia, and indole to best correlate with spoilage of blue crab meat. TMA was found to be sensitive to the minor changes in the early stages (0 - 4 days of refrigerated storage) of spoilage for blue crab meat. Indole corresponded well with sensory results, which suggests that indole may be a promising indicator for detecting early, mid, and highly spoiled samples. It is feasible that these methods can be applied to other crustaceans to determine spoilage level. / Master of Science in Life Sciences

Blue crabs are a widely distributed estuarine species with broad economic and ecological importance. Several studies have linked blue crabs to freshwater inflows, but the precise nature of this link is still uncertain, as blue crabs have a complex life cycle that utilizes both marine and estuarine environments. One potential link between blue crabs and freshwater inflows is during recruitment, when megalopae developing offshore return to estuaries before molting into juvenile crabs. Megalopae swim during the flood tide to ensure delivery into and farther up estuaries. The behaviors regulating selective tidal stream transport (STST) on the flood tide were originally studied in North Carolina in an estuary with regular freshwater inflows and a strong salinity gradient. The model of STST was re-examined in the Mission-Aransas, an estuary with episodic freshwater inflows and salinity gradients ranging from normal estuarine conditions to hypersaline during droughts. The behavioral responses of megalopae to a range of rates of salinity increase were tested, and then modeled onto rates of salinity change observed in the field to determine the theoretical ecological consequences of STST for blue crab populations in the Mission-Aransas Estuary. To validate the ecological trends predicted by the behavioral model of STST, a simple, long-term data set reflecting changes in megalopae abundance is needed. Hog’s hair collectors are a simple and widely used method of quantifying abundance of brachyuran megalopae, including blue crabs. However, the efficiency of hog’s hair collectors in sampling for megalopae is unknown. Several studies have reported poor correlations between settlement on hog’s hair collectors, transport, and abundance of megalopae in the plankton due to disparate temporal scales and potentially turbulence-driven decoupling. Each of these issues were addressed in field and flume experiments, which were used to develop a model for interpreting settlement on hog’s hair collectors in terms of transport and planktonic abundance. / text

Thesis (Ph. D.)--Florida State University, 2005. / Advisor: Bruce R. Locke, Florida State University, FAMU-FSU College of Engineering, Dept. of Chemical and Biomedical Engineering. Title and description from dissertation home page (viewed Jan. 12, 2006). Document formatted into pages; contains xix, 250 pages. Includes bibliographical references.

Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2006. / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-11-19T11:17:25Z No. of bitstreams: 1 Dissertacao Marcos.pdf: 1118373 bytes, checksum: 7a93dd33316a5f05afa5bd7d2f611436 (MD5) / Approved for entry into archive by Angelica Miranda (angelicacdm@gmail.com) on 2013-11-20T21:49:31Z (GMT) No. of bitstreams: 1 Dissertacao Marcos.pdf: 1118373 bytes, checksum: 7a93dd33316a5f05afa5bd7d2f611436 (MD5) / Made available in DSpace on 2013-11-20T21:49:31Z (GMT). No. of bitstreams: 1 Dissertacao Marcos.pdf: 1118373 bytes, checksum: 7a93dd33316a5f05afa5bd7d2f611436 (MD5) Previous issue date: 2006 / Devido à falta de estruturas rígidas para determinação de idade em crustáceos, métodos que se baseiam na determinação de idade através de freqüência de tamanhos são comumente utilizados. Neste trabalho, foram estudados aspectos do crescimento em laboratório e no ambiente, de juvenis e adultos, do siri-azul Callinectes sapidus, com o objetivo de desenvolver uma metodologia adequada à obtenção do siri-mole (softcrab) no estuário da Lagoa dos Patos. Os indivíduos de laboratório foram coletados e acompanhados individualmente. A biometria foi realizada antes e depois das mudas. A temperatura foi mantida constante (25±2°C) e a salinidade foi mantida a 20±5. Os indivíduos do ambiente foram coletados entre 2002 e 2003 em pontos prédeterminados no estuário da Lagoa dos Patos, com rede de portas. A obtenção das curvas de crescimento se baseou nos modelos de Gompertz e Bertalanffy, neste último utilizou-se o método de determinação de idade através do acompanhamento do deslocamento modal. Foram utilizados aspectos biológicos conhecidos da espécie para validar as curvas de crescimento. O tamanho máximo de largura de carapaça utilizado foi mantido fixo em todas as análises (157,78 para fêmeas e 162,71 para machos). A curva de Gompertz foi aplicada aos indivíduos menores cultivados em laboratório e os parâmetros obtidos foram k=0,0238/dia; co=4,15; longevidade de 2530 dias para machos e k=0,00375/dia; co=4,69; longevidade de 1638 dias para fêmeas. A curva de Bertalanffy foi determinada através da análise de progressão modal. Para os maiores indivíduos cultivados em laboratório os parâmetros e a longevidade obtidos foram k=0,0016/dia; to=-0,7; longevidade de 3117 dias para machos e k=0,0018/dia; to=-12,6; longevidade de 2795 dias para fêmeas. Os parâmetros de crescimento e a longevidade estimados para os animais coletados no ambiente foram k=0,04502/dia; to=-4,23; 1267 dias para machos e k=0,04271/dia; to=-3,71; 1260 dias para fêmeas. Os animais de laboratório exibiram crescimento diferente dos animais do ambiente, as estimativas mostram os siris crescendo menos e tendo longevidades maiores. O sistema de cultivo utilizado para a manutenção dos animais em laboratório mostrou-se eficiente. A obtenção do siri-mole poderá ser uma fonte alternativa de renda para os pescadores artesanais. / The absence of hard structures capable of register age on crustacean, requires the use of methods such as modal progression analysis (MPA) to estimate growth. In this paper, growth and mortality of juveniles and adults of the blue crab Callinectes sapidus were studied through field and laboratory surveys, in attempt to develop an adequate method to obtain softcrabs on the Patos Lagoon estuary. Gompertz and von Bertalanffy curves were used to estimate growth parameters of blue crabs collected on the Patos Lagoon estuary. Crabs obtained from field sampling were kept under laboratory conditions (temperature = 25±2°C, and salinity = 20±5), on a water recirculating system and measured before and after molting. Individuals used for growth and mortality analysis were collected between 2002 and 2003 in predetermined sampling sites by using otter-trawl and renfro nets. Measures consisted of carapace length, taken from the last antherolateral spines (CL in millimeters) and wet weight (W in grams). Maximum carapace lengths used as asymptotic length were taken from long term catch series of larger individuals and used to validate the growth curves (157.78 mm for females and 162.71 mm for males). Growth estimates based on Gompertz model for smaller individuals reared in laboratory, were as follows: k=0.0238; co=4.15; longevity= 2530 days for males and k=0.00375; co=4.69; longevity= 1638 days for females. Growth estimates based on von Bertalanffy growth curve were k=0.0016/day; to=-0.7; longevity= 3117 days for males and k=0.0018/day; to=-12.6; longevity= 2795 days for females. Growth parameters and longevity estimates for the field collected animals were k=0.04502/day; to=-4.23; 1267 days for males and k=0.04271/day; to=-3.71; 1260 days for females. No significant correlation was obtained among laboratory and field animals, suggesting a different growth rate. The Patos Lagoon estuary shows good potential for the establishment of a softcrab facility, as an alternative income for the artisanal fisheries.

No description available.

The 2010 Deepwater Horizon oil spill resulted in the accidental release of millions of barrels of crude oil into the Gulf of Mexico (GoM). Photo-induced toxicity following co-exposure to ultraviolet (UV) radiation is one mechanism by which polycyclic aromatic hydrocarbons (PAHs) from oil spills may exert toxicity. Blue crab (Callinectes sapidus) are an important commercial and ecological resource in the Gulf of Mexico and their largely transparent larvae may make them sensitive to PAH photo-induced toxicity. Mahi-mahi (Coryphaena hippurus), an important fishery resource, have positively buoyant, transparent eggs. These characteristics may result in mahi-mahi embryos being at particular risk from photo-induced toxicity. Red drum (Sciaenops ocellatus) and speckled seatrout (Cynoscion nebulosus) are both important fishery resources in the GoM. They spawn near-shore and produce positively buoyant embryos that hatch into larvae in about 24 h. The goal of this body of work was to determine whether exposure to UV as natural sunlight enhances the toxicity of crude oil to early lifestage GoM species. Larval and embryonic organisms were exposed to several dilutions of water accommodated fractions (WAF) from several different oils collected in the field under chain of custody during the 2010 spill and two to three gradations of natural sunlight in a factorial design. Here, we report that co-exposure to natural sunlight and oil significantly reduced larval survival and embryo hatch compared to exposure to oil alone.

Post-pelagic juvenile and subadult Kemp's ridley sea turtles (Lepidochelys kempii) (20-40 cm straight carapace length) utilize nearshore waters of the northwestern Gulf of Mexico as nursery or developmental feeding grounds. This study utilizes 10 years of entanglement netting data to characterize long-term abundance and distribution of Kemp's ridley sea turtles at index habitats in this region. Netting surveys were conducted during April-October 1993-2002, primarily at Sabine Pass, Texas and Calcasieu Pass, Louisiana. Additionally, this study takes an ecosystem-based approach to understanding factors influencing Kemp's ridley in-water abundance and distribution via the development of a conceptual model incorporating data on nesting dynamics, environmental conditions, prey availability, and predation pressure. Overall monthly mean ridley catch-per-unit-effort (CPUE) peaked in the beginning of summer (April-June), probably in response to rising water temperatures and seasonal occurrence of blue crab prey. Annual mean ridley CPUE across all study areas peaked in 1994, 1997, 1999 and 2002, suggesting a 2-3 year cycle in abundance that may be related to patterns in clutch size or hatch success at the Rancho Nuevo, Mexico nesting beach. However, ridley CPUE in nearshore waters remained relatively constant or decreased slightly even as number of hatchlings released from Rancho Nuevo increased exponentially. Annual declines in Texas strandings since 1994 and subsequent increases in Florida counterparts since 1995 suggest a shift in ridley distribution from the western to eastern Gulf in recent years. Significant declines in ridley CPUE at Sabine Pass since 1997 coincided with a concurrent reduction in blue crab size, but a similar trend was not detected at Calcasieu Pass. Kemp's ridley occurrence at study sites was not significantly related to shrimping activity/by-catch. There also were no biologically significant relationships between Kemp's ridley CPUE and abiotic factors, nor were ridleys deterred from utilizing areas frequented by bull sharks. Overall, nesting dynamics and prey availability were conceptual model components appearing to have the greatest influence on nearshore ridley occurrence.

No description available.

I conducted a 12-month study of near-shore habitats in Lake Pontchartrain to assess spatiotemporal variation in the abundance of early life stage blue crabs (Callinectes sapidus). Collections were made using a 1 m2 throw trap and data showed that C. sapidus numbers varied over time and among sites. Two recruitment events occurred during the study. During the first recruitment in May-June, C. sapidus entered Lake Pontchartrain via the Inner Harbor Navigational Canal. In September-October, C. sapidus entered the Lake Pontchartrain via the Rigolets and Chef passes. My data suggest that C. sapidus utilize water circulation within the Lake Pontchartrain as a means of transportation throughout the estuary. MODerate-resolution Imaging Spectroradiometer (MODIS) 250 m data were analyzed to gain a large-scale view of suspended sediments patterns within Lake Pontchartrain and quantify water movement. Field sampling along with remote sensing proved to be beneficial when assessing estuarine-wide C. sapidus post-larval dispersal processes.

[ES] El cangrejo azul Callinectes sapidus es un cangrejo nadador de gran tamaño que se ha asentado en distintos lugares alrededor del mundo como especie invasora, incluida la costa mediterránea española, en la que cuenta con una fuerte presencia. Es natural de la costa atlántica de América, desde Canadá a Argentina. Es eurihalino y euritermo, voraz, y capaz de alcanzar altas densidades de población, por tanto, capaz de provocar graves impactos sobre el ecosistema autóctono. Vive habitualmente en sistemas estuarinos, que las hembras abandonan para completar su complejo ciclo vital. Se trata de una especie de interés comercial, ampliamente explotado en su zona de distribución nativa. En este estudio se han llevado a cabo un total de 7 campañas de muestreo para obtener información sobre cada una de las fases de su ciclo de vida. Para obtener información sobre la etapa inicial de vida planctónica se realizaron arrastres pelágicos. Para capturar megalopas y juveniles se emplearon colectores pasivos, y nasas para capturar adultos. Estas campañas de muestreo proporcionan información espacial y temporal sobre cada una de estas fases. En el caso de los individuos adultos permiten caracterizar su población en base al tamaño promedio de los individuos y la proporción de sexos. Además, se han realizado experimentos de modelado y simulación para determinar su posible impacto sobre las especies locales. Por una parte, se han llevado a cabo experimentos de competencia contra Pachygrapsus marmoratus, y por otra, se ha desarrollado un modelo de la red trófica de L'Albufera en "Ecopath with Ecosim". El conjunto de las campañas de muestreo revela un ciclo vital bien definido, con un periodo de apareamiento en abril-junio, una migración reproductiva en julio, un máximo de zoeas en agosto y el periodo septiembre-noviembre como el más importante a lo largo del año para la colonización de sistemas estuarinos por parte de megalopas y juveniles. Las zoeas fueron más abundantes a 1000 m de la costa, y la población de adultos capturados poseía un tamaño promedio elevado y una proporción de sexos con mayoría de hembras. Se capturaron adultos en todas las estaciones del año. P. marmoratus no se ve especialmente afectado por la presencia de C. sapidus. Según el modelo, la especie más afectada por C. sapidus en L'Albufera es Procambarus clarkii, existiendo impactos variados sobre otras especies. La pesca se revela como un mecanismo eficaz de control de la población de C. sapidus. / [CA] El cranc blau Callinectes sapidus és un cranc nadador de gran grandària que s'ha assentat en diferents llocs al voltant del món com a espècie invasora, inclosa la costa mediterrània espanyola, en la qual compta amb una forta presència. És natural de la costa atlàntica d'Amèrica, des del Canadà a l'Argentina És eurihalino i euritermo, voraç, i capaç d'aconseguir altes densitats de població, per tant, capaç de provocar greus impactes sobre l'ecosistema autòcton. Viu habitualment en sistemes estuarinos, que les femelles abandonen per a completar el seu complex cicle vital. Es tracta d'una espècie d'interés comercial, àmpliament explotat en la seua zona de distribució nativa. En este estudi s'han dut a terme un total de 7 campanyes de mostreig per a obtindre informació sobre cadascuna de les fases del seu cicle de vida. Per a obtindre informació sobre etapa inicial de vida planctònica es van realitzar arrossegaments pelàgics. Per a capturar megalopas i juvenils es van emprar col·lectors, i nasas per a capturar adults. Estes campanyes de mostreig proporcionen informació espacial i temporal sobre cadascuna d'estes fases. En el cas dels individus adults permeten caracteritzar la seua població sobre la base de la grandària mitjana dels individus i la proporció de sexes. A més, s'han realitzat experiments de modelatge i simulació per a determinar el seu possible impacte sobre les espècies locals. D'una banda, s'han dut a terme experiments de competència contra Pachygrapsus marmoratus, i per una altra, s'ha desenvolupat un model de la xarxa tròfica de L'Albufera en "Ecopath with Ecosim". El conjunt de les campanyes de mostreig revela un cicle vital ben definit, amb un període d'aparellament a l'abril-juny, una migració reproductiva al juliol, un màxim de zoeas a l'agost i el període setembre-novembre com el més important al llarg de l'any per a la colonització de sistemes estuarinos per part de megalopas i juvenils. Les zoeas van ser més abundants a 1000 m de la costa, i la població d'adults capturats posseïa una grandària faig una mitjana d'elevat i una proporció de sexes desviada cap a les femelles. Es van capturar individus adults en totes les estacions de l'any. P. marmoratus no es veu especialment afectat per la presència de C. sapidus. Segons el model, l'espècie més afectada per C. sapidus en L'Albufera és Procambarus clarkii, existint impactes variats sobre altres espècies. La pesca es revela com un mecanisme eficaç de control de la població de C. sapidus. / [EN] The blue crab Callinectes sapidus is a large swimming crab that has settled in different places around the world as an invasive species, including the Spanish Mediterranean coast, where it has a strong presence. It is native to the Atlantic coast of America, from Canada to Argentina. It is euryhaline and eurythermic, voracious, and capable of reaching high population densities, therefore, capable of causing serious impacts on the native ecosystem. It usually lives in estuarine systems, which the females leave to complete their complex life cycle. It is a species of commercial interest, widely exploited in its native range. In this study, a total of 7 sampling campaigns were carried out to obtain information on each of the stages of their life cycle. To obtain information on the initial stage of planktonic life, pelagic trawls were used. Collectors were used to capture megalopae and juveniles, and traps were used to capture adults. These sampling campaigns provide spatial and temporal information on each of these stages. In the case of adult individuals, they allow us to characterize the population based on the average size of the individuals and the sex ratio. In addition, modeling and simulation experiments have been carried out to determine their possible impact on local species. On the one hand, competition experiments have been carried out against Pachygrapsus marmoratus, and on the other hand, a model of the food web of L'Albufera has been developed in "Ecopath with Ecosim". The set of sampling campaigns reveals a well-defined life cycle, with a mating period in April-June, a reproductive migration in July, a maximum of zoeas in August and September-November as the most important period throughout the year for the colonization of estuarine systems by megalopae and juveniles. Zoeas were most abundant at 1000 m offshore, and the population of adults captured had a high average size and a sex ratio skewed towards females. Adult individuals were captured in all seasons. P. marmoratus is not particularly affected by the presence of C. sapidus. According to the model, the species most affected by C. sapidus in L'Albufera is Procambarus clarkii, with varied impacts on other species. Fishing is shown to be an effective mechanism for controlling the population of C. sapidus. / Gil Fernández, A. (2024). Adaptación e impacto ecosistémico de Callinectes sapidus Rathbun, 1896 en la costa mediterránea española: caso de L'Albufera de Valencia [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/211375