Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 34 for “"Sea urchins"”.
-
Systematics and biodiversity of South African sea urchins
… lowest in>500m.This maybe a result of the deep-seas (>500m) being severely under-sampled. The lack of full-time taxonomists and lack of expertise to review this group, may have contributed to the high number of new records.
-
Hydrogen peroxide-induced genotoxicity and transgenerational implications in sea urchins
… is an antiparasitic treatment against sea lice in Atlantic salmon aquaculture and is released into the surrounding waters. H<sub>2</sub>O<sub>2</sub> is presumed to degrade and dilute rapidly within days and considered environmentally friendly. However, modelling studies showed …
-
COLLAGEN AND ANTIOXIDANTS FROM SEA URCHINS: WASTE VALORIZATION CHALLENGES TOWARDS REGENERATIVE MEDICINE
Sea urchins (mainly Paracentrotus lividus) are well known worldwide as a delicacy that is processed in the food industry or consumed directly in restaurants. The gonads are the only edible part of these marine animals, while the rest (more than 90-95% of their total mass) is discarded as waste. …
-
Distributional relationships among subtidal algae, sea urchins and reef fish in northeastern New Zealand
Interactions among large brown macroalgae, sea urchins, and fishes were investigated in northeastern New Zealand during the period 1988 - 1993. The Cape Rodney to Okakari Point Marine Reserve was the site of many of these investigations. The patterns of abundance of large brown macroalgae and …
-
Development of an embryo-larval chronic toxicity test using the sea urchins Tripneustes gratilla and Echinometra mathaei
… and ecologically relevant. Gametes of the sea urchins Echinometra mathaei and Tripneustes gratilla are used for acute toxicity testing purposes in South Africa through the fertilisation test (e.g. for testing effluents and seawater samples). However, this test has raised questions on the …
-
The primary structure of histones H2B from sperm of the sea urchins Parechinus angulosus and Psammechinus miliaris
Histones H2B have been purified from sperm of the sea urchin Parechinus angulosus and Psammechinus miliaris. Three H2B variants have been completely sequenced from P. angulosus and two H2B variants from P. miliaris have been partially sequenced. The sequences of the sperm histones H2B are compared …
-
The feasibility of a commercial-scale recirculating aquaculture system integrating sea urchins (Tripneustes gratilla) and seaweed (Ulva)
It has been proposed that the highly valued sea urchin, Tripneustes gratilla, and the green macroalga, Ulva, could be suitable co-candidates for a land-based recirculating Integrated MultiTrophic Aquaculture (IMTA) system. This IMTA system is suggested to be sustainable and efficient, primarily …
-
Ecological interactions between abalone (Haliotis midae) juveniles and sea urchins (Parechinus angulosus), off the south-west coast of South Africa
… of a strong positive relationship between the urchins Parechinus angulosus and juveniles of the abalone Haliotis midae. Both species occupied primarily hard substrates, showing preferences for encrusting corallines. Of the juvenile abalone sampled, > 98% were found beneath sea urchins. All …
-
A study of the infestations occurring in Parechinus Angulosus
… has been steadily growing. Work has been done on sea urchins from Bermuda, Tortugas, the east and west coasts of Japan, the coast of North Carolina; the coast of California, the Mediterranean Sea. and the North Sea. The present paper deals with the sea urchin Parechinus Angulosus, the only species …
-
Effects of Bisphenol-A and Styrene on Fertilization and Development of the Purple Sea Urchin (Strongylocentrotus purpuratus)
… and get ingested by marine mammals, turtles, and sea birds, but they also leach chemicals, such as bisphenol-A (BPA) and styrene into the aquatic environment. While some of these chemicals are known to be toxic, few studies have examined their effects on broadcast spawning marine invertebrates, …
-
Assessment of predation by the West Coast rock lobster (Jasus lalandii) : relationships among growth rate, diet and benthic community composition, with implications for the survival of juvenile abalone (Haliotis midae)
… on the benthos, but more specifically on sea urchins and juvenile abalone.
-
Evaluating in situ Grazing Patterns of Lytechinus variegatus and their Effects on Seagrass Beds of Thalassia testudinum
<p>The sea urchin<em> Lytechinus variegatus </em>is a known grazer of the seagrass <em>Thalassia testudinum</em>, and has been known to denude vast stands of seagrass beds at high densities. Outside of these denudation events, the effects of sea urchins on seagrass are poorly understood. This study …
-
Development of scientifically base management towards a sustainable fishery of the common sea urchin, Paracentrotus Lividus, in Sardinia
In recent years sea urchins have become a premium commodity in the world where both males and females of the species are harvested for their gonads, generally referred to as “roe” in the fishery and catering market. Fishing for sea urchins can be a very profitable business during the first 5 to 10 …
-
Deoxyribonuclease probing on sea urchin embryo chromatin
The role that the sea urchin, Parechinus angulosus, embryo and sperm histone variants play in chromatin structure has been investigated. Chromatin structure has been determined at different levels of resolution in sperm and in developing embryos using micrococcal nuclease, pancreatic …
-
Attractant properties of chemical constituents of the green macroalga Ulva and their response effects on the commercially important sea urchin Tripneustes gratilla
Interest in commercial sea urchin aquaculture is growing worldwide. This is because sea urchins have good quality roe which is a delicacy in many countries. Since the quality of sea urchin roe is dependent on what the sea urchin eats, increased research is being carried out to understand sea urchin …
-
Biomarkers (lipids, fatty acids and stable isotopes) to examine diet of the sea urchin Evechinus chloroticus.
… improve the knowledge of feeding habits of wild sea urchins from north-eastern New Zealand, revealing a high contribution from Ecklonia radiata to E. chloroticus diets, but also a contribution from Carpophyllum plumosum in the Hauraki Gulf. The use of lipid and fatty acid composition of E. …
-
Acid-base regulation in the sea urchin Parechinus angulosus during CO₂-induced seawater acidification
… rates and weak ability to regulate ion exchange, sea urchins are thought to be particularly weak acid-base regulators. Recent findings showing species-specific capacities for extracellular pH regulation however suggest that species currently exposed to natural CO₂ elevations, such as upwelling …
-
Assessing the potential of the unexploited South African Cape sea urchin, Parechinus angulosus, as a new aquaculture species
Sea urchins are harvested for their gonads, otherwise known as “uni”, that have a high market value, particularly in Asian countries such as Japan and China. Over the last few decades, the market for ‘uni' has steadily expanded. Current and future demand for sea urchin products cannot be met by the …
-
The histone H1 of the sea urchin embryo, partial structures, enzymatic modifactions and developmental programme
Developmental biology owes a tremendous debt to sea urchins. These animals have proved to be experimental jewels, and since they are distributed abundantly along the Peninsula coastline, they are readily at hand. Sea urchin embryos have been shown to be extremely well suited for analysis of …
-
Multi-stressor impacts of ocean warming and acidification on the regeneration andbiomineralisation of <i>Psammechinus miliaris</i>
… are vital for survival, mobility, and defence. Sea urchins, as ecologically important benthic grazers, rely on the ability to regenerate tube feet and calcify spines to maintain function in dynamic coastal habitats. This thesis investigates the response of the coastal sea urchin Psammechinus …
Page 1 of 2