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.
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Showing 1 to 10 of 10 for “"Echinoidea"”.
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The foraging strategy of Diadema antillarum (Philippi) (Echinodermata: Echinoidea)
<p>Diadema antillarum (Philippi) is a common echinoid grazer in Caribbean reef areas. Field observations in st . Croix, u.s.v.r. an.d Disc. overy Bay, Jamaica and laboratory experiments demonstrate that these urchins have a strong feeding preference for algal turf. Seasonal variation in the …
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Estratégia reprodutiva e gametogênese de Cassidulus mitis Krau, 1954 (Echinodermata: Echinoidea)
Cassidulus mitis Krau is an endemic species from Rio de Janeiro, Brazil. To verify its reproductive cycle, samples were taken from October 1998 to April 2000 at Vermelha Beach. Sex ratio of 1 (x2= 1.48; a0.05=3.84; DF= l) was found for C. mitis. Reproduction occurs overall the year. Gonadal index …
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Modelagem matemática do crescimento somático e mortalidade do ouriço-do-mar Cassidulus mitis Krau, 1954 (Echinoidea: Cassidulidae)
The somatic growth of Cassidulus mitis Krau, 1954, a tropical brooding species, from a population located at the Vermelha Beach, Rio de Janeiro, Brazil, was analyzed by observing the monthly size distributions from December 1998 to April 2000, as well as by a mark-recapture experiment. These data …
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The reproduction and recruitment of the sand dollar Arachnoides placenta (L.) (Echinoidea: Echinodermata) from differing habitats on the North Queensland coast
The reproductive periodicity, recruitment and population studies of the intertidal Indo-Pacific echinoid, Arachnoides placenta (Linnaeus), were investigated from April 2001 to September 2002 at sites along 650km of the north Queensland coast, Australia. Three locations were sampled, comprising …
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Comparação interpopulacional de caracteres morfológicos e reprodutivos do ouriço-do-mar Arbacia lixula (Linnaeus, 1758) (Echinodermata: Echinoidea) em duas localidades do litoral do estado do Rio de Janeiro
Arbacia lixula (Linnaeus, 1758) is a common echinoid on the Brazilian coast, although there are few studies about this species in the South Atlantic Ocean. This work aims to compare morphological and reproductive traits in two sea urchin populations and verify the reproductive cycle of Arbacia …
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Exploring the morphospace of cidaroid echinoid spines.
Crown group cidaroids (Echinodermata: Echinoidea: Cidaroida) display a variety of spine morphologies thought to be adapted in response to selective pressures around them. Echinoid spines directly interact with their surroundings and morphologies should reflect environmental conditions changing …
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Systematics and biodiversity of South African sea urchins
The South African Echinoidea (Echinodermata) were last reviewed by Clark & Courtman Stock (1976) and numerous unidentified specimens and records have accumulated since that time, plus there have been many taxonomic changes within the group. Therefore this study, which forms the first of its kind in …
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Marine invertebrate sperm: assessment of sperm quality using computer-aided sperm analysis
… invertebrates, namely Parechinus angulosus (Echinoidea), Choromytilus meridionalis (Bivalvia), Crassostrea gigas (Bivalvia), Donax serra (Bivalvia) and Haliotis midae (Gastropoda) were investigated. The sperm morphology and base-line data were gathered concerning the sperm concentration, …
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Post-larval development in deep-sea echinoderms
… to three classes (Ophiuroidea, Asteroidea and Echinoidea), is described using scanning electron microscopy. The life history of Ophiocten gracilis is also examined as a case study for future research on post-larval organisms. The analysis of development in ophiuroids reveals that species can be …