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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Growth, survival, haemolymph osmolality and organosomatic indicies of the Western King prawn (Penaeus latisulcatus Kishinouye, 1896) reared at different salinities

Huynh, Minh Sang January 2003 (has links)
The western king prawn (Penueus Zarisulcutus) is one of the most economically valuable species of crustacean in Australia. The experiment was carried out for 60 days to determine the growth, survival, haemolymph osmolality and organosomatic indices of the western lung prawn (2.95 f 0.26 g mean initial weight) reared at 10, 22, 34 and 46 g L of salinities. In addition, haemolymph osmolality and osmoregulatory capacity (OC) of the western king prawn (5.37 f 0.1 g mean initial weight) reared at salinities (10, 22, 34 and 46 g/L) were determined following 7, 14 and 21 minutes of air exposure and compared with the brown tiger prawn (P, esculentus). Mean final weight, total length, carapace length and specific growth rate (SGR) of the western king prawn were highest at a salinity of 34 g/L. Moult increments (in weight and total length) of the western king prawn were not significantly different (P > 0.05) when reared at four different salinities. Food conversion ratios were lowest in prawns reared at salinities of 22 and 34 g/L. Survival of the western king prawn was highest at a salinity of 22 g/L and lowest at a salinity of 10 g/L. Haemolymph osmolality of the western king prawn increased with an increase in salinity and weight. Isosmotic points of the western king prawn calculated from regression lines between haemolymph and medium osmolality were 28.87, 29.46 and 31.73 g / L at 0, 20 and 60 days of rearing (accordingly to 2.95 f 0.26; 4.02 f 0.47; 5.79 f 0.64 g body weight), respectively. Tail moisture content of the western king prawn decreased with the increase of salinity. After 60 days of rearing, the lowest hepatopancreas moisture content of the prawns was at a salinity of 22 gL. Wet weight and dry weight hepatosomatic indices of the prawns were highest when reared at a salinity of 22 gL. / Wet weight and dry weight tail muscle indices of the prawns were highest at a salinity of 34 gL. Isosmotic points of the western king prawn were 33.79; 33.29; 32.75 and 33.10 g/L at 0, 7, 14, and 21 minutes of air exposure, respectively. Isosmotic points of the brown tiger prawn were 30.89; 31.89; 32.09 and 31.07 g/L at 0, 7, 14, and 21 minutes of air exposure, respectively. Air exposure reduced OC of both the western king prawn and brown tiger prawn. OC of both species at a salinity of 10 giL was reduced significantly after 14 minutes of air exposure. Twenty-one minutes of air exposure did not change OC of the western king prawn reared at salinities of 22, 34 and 46 g/L. OC of brown tiger prawn reared at 22 g/L decreased after 21 minutes of air exposure while OC of the brown tiger prawn reared at 46 g/L decreased after 7 minutes of air exposure. The results indicate that both species spent less energy on osmoregulation at 34 gL salinity than at other salinities. The results suggest that the optimum salinity for rearing of western king prawns ranges from 22 g/L to 34 g/L. Salinities of 10 and 46 gL are unsuitable for rearing brown tiger prawns and salinity 10 g/L is unsuitable for rearing western king prawns. Furthermore, a salinity range from 30 g/L to 32 gL is suitable for the culture of brown tiger prawns.
2

Studies on the utilisation of scampi (Nephrops norvegicus) waste with special reference to hyaluronidase

Krishnapillai, Ashok M. January 1994 (has links)
No description available.
3

Excitation-contraction coupling in muscles of the Norway lobster Nephrops norvegicus

Holmes, Janet January 1997 (has links)
No description available.
4

Comparative histological, histochemical, ultrastructural, scanning electron microscopic and functional studies of the integumental glands ...of A. Salina

Abd El-All, M. A. H. January 1988 (has links)
No description available.
5

Hormones in cirripedes

Clare, Anthony S. January 1984 (has links)
No description available.
6

Presence of Paragonimus species Within the Secondary Crustacean Hosts in Bogotá, Colombia

Phillips, Gillian 08 January 2016 (has links)
Paragonimus spp. are parasites that infect many populations worldwide. It is predicted that infection rates within Asia reach ten to fifteen percent of the total population. Three largest areas of possible infection are Asia, Central and South America as well as Africa where the total population at risk is estimated to be 293 million people. Ingestion of raw or undercooked crustaceans are the source of infection to mammals. The crustaceans Neostrengeria macropa and Procambarus clarkii in Bogotá, Colombia were collected from local markets, pet stores and waterways. Dissection for presence of parasites is imperative to estimate the prevalence of crustacean infection by lung flukes. The preliminary findings show, pending laboratory confirmation, that the native crab species, N. macropa, has a prevalence of 17.2% infection. Invasive crayfish species, P. clarkii has a prevalence of 36.4% from both captive and field capture samples. While the prevalence estimated within this study is lower than compared to previous research in other cities of Colombia, there may be a number of factors that contribute to the difference in prevalence including: collecting season, overall low rainfall, temperature, altitude and the El Niño Southern Oscillation.
7

Aspects of biogeography, systematics and ecolomorphology of deep-sea Tanaidacea (Crustacea, Peracarida)

Hassack, E. January 1987 (has links)
No description available.
8

Anatomy and Lengthening Velocity of Muscles in the Lobster Stomatogastric System

Thuma, Jeffrey B. 20 April 2007 (has links)
No description available.
9

Phylogeographic Analyses of Obligate and Facultative Cave Crayfish Species on the Cumberland Plateau of the Southern Appalachians

Buhay, Jennifer Elizabeth 12 July 2006 (has links) (PDF)
Cave systems and their unique biota are widely viewed as highly endangered, yet very little is known about basic life history, ecology, distributions, habitat requirements, and evolutionary relationships of subterranean species. The crux of the problem in cave studies is the assumption that traditionally defined morpho-species represent distinct evolutionary lineages. Convergence is exhibited in the morphologies of many animal groups, vertebrate and invertebrate, which leads to confusion in diagnosing species' boundaries, geographic distributions, gene flow routes, and imperilment. This dissertation research includes phylogeographic analyses of freshwater cave-dwelling crayfishes in the Southern Appalachians, a global hotspot of subterranean biodiversity. By examining population structure in light of habitat, geology, geography, and hydrology, we can better provide conservation direction for these groundwater species. Chapter one introduces a method, Nested Clade Phylogeographic Analysis (NCPA), used to investigate hypotheses about historical and current population structures within species. Using a statistically-testable framework, NCPA can elucidate historical speciation patterns and current routes of gene flow using genetic sequence data of thoroughly-sampled species. Using diverse examples, the chapter details the methodology of building haplotype networks, performing the geographic analyses, inferring past and contemporary evolutionary patterns and processes, and delineating species' boundaries. Chapter two examines two competing hypotheses regarding conservation status of cave-dwelling species using a wide-ranging group of obligate subterranean crayfish species on the Cumberland Plateau's western escarpment. Using a population genetic approach, cave crayfish exhibited moderate to high levels of genetic diversity and attained large population sizes over their evolutionary histories. Phylogeographic analyses revealed that this crayfish assemblage originated along the northern end of the Cumberland Plateau and in leading-edge small steps, colonized southward and accumulated diversity along the way. Current species' boundaries do not match traditional morpho-species designations and also do not match current hydrological units. Chapter three explores phylogeography and habitat differences within the facultative cave-dwelling crayfish species Cambarus tenebrosus. This freshwater species is unique in that it inhabits surface and subsurface karst environments, has an unusually large distribution, and exhibits troglomorphism with reduced eyes and elongated limbs. Using sequence data from over 100 sampled localities, mostly along the Cumberland Plateau, C. tenebrosus appears to have inhabited surface and subsurface biomes throughout its evolutionary history. Additionally, this species shows extremely high levels of genetic diversity and NCA revealed significant phylogeographic structure within the species, but there was no significant relationship between habitat and genetic structure. Chapter four examines the obligate cave crayfish assemblage, genus Cambarus, subgenus Aviticambarus, which ranges across the southernmost area of the Southern Appalachians, which is known to contain the highest species diversity of obligate terrestrial animals in the United States. The Aviticambarus assemblage is only currently known from 58 caves in Alabama and Tennessee, and with samples from half of the known sites, this study uncovered additional lineages previously obscured by convergent morphology. These species show low levels of genetic diversity and populations that do not appear to be expanding. Species' boundaries are supported by geologic and phylogeographic information, but not current drainage basin boundaries.
10

Use of Stable Isotope and Trace Metal Signatures to Track the Emigration of Female Blue Crabs, Callinectes sapidus, from Tampa Bay

Williams, Sky Barrington 01 January 2013 (has links)
The blue crab, Callinectes sapidus, supports a successful fishery in the Atlantic Ocean and throughout the Gulf of Mexico, with a total landing of 8,158,788 lb. and a total value of $10,562,128 for the state of Florida during 2012 (FWC 2012 Annual Landings Summary). An accurate and comprehensive understanding of the blue crab's life history and seasonal migration behavior is essential in defining effective management strategies for the fishery. Tag recapture studies and ultrasonic tracking methods for studying blue crab migrations are costly in terms of time and resources. In this study an alternative approach, microchemical natural tagging, was successfully used to determine a female's mating habitat. This approach assumes that the exoskeleton of the post-terminal molt female blue crab reflects the mating habitat's chemical signature and that the chemical signals are stable over time. To test these hypotheses, mature female blue crabs were collected from two Tampa Bay locations. Collected crabs were placed in tanks for 29 days, a subset was sacrificed at T = 0 and then twice per week, and the exoskeletons were analyzed via Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Elemental Analyzer Infrared Mass Spectrometry (EA-IRMS) to observe the stability of the exoskseletal chemical signature over time. Over the 29 day time series, no significant change in the concentrations of Li, Ca, and Ba, or the isotopic ratios of 13C/12C (δ13C) and 15N/14N (δ15N) were observed (ANOVA p-value > 0.05). A Canonical Analysis of Principal Coordinates (CAP)-based discriminate analysis with leave-one-out cross-validation collectively compared Li concentrations, δ13C, and δ15N among five Tampa Bay locations, producing a confusion matrix successfully classifying field collected crabs into: Alafia River 33%#37;, Little Manatee River 71%#37;, Palm River 67%#37;, Safety Harbor 30%#37;, and Skyway Fishing Pier 83%#37;, with an overall classification success of 66%#37;. These results suggest that the largest biomass component of the migratory pulse collected near the mouth of Tampa Bay was dominated by crabs originating from an area not widely harvested by commercial fishermen, as relatively few of the migrating females were matched to riverine locations that were intensively fished. Instead, most appeared to originate from open waters of Tampa Bay. It is possible that low densities of blue crab inhabiting a large area that is not commercially fished, effectively shields a proportion of the individuals in the Tampa Bay estuary from economic exploitation, creating a density-dependent natural harvest refugium.

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