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strategy stablished by the Winemiller and Rose model (1992) and the large egg size characteristic of the species inhabiting deep cold waters. Conversely, phylogenetic and evolutionary factors are also important and seem to be decisive at the deepest waters where basically mainly species belonging to the strict deep-sea family Porcellanasteridae are found. All these species possess a mixture of features proper of classical K strategists and the equilibrium strategists proposed by Winemiller and Rose (1992), which enable them to persist in the relatively stable environment with low energy availability that characterizes the great abyssal plains. 93
CHAPTER FIVE- SYNTHESIS AND CONCLUSIONS 5.1- Factors controlling the bathymetric distribution of species and their effects on early life-history stages of echinoderms The factors that control the diversity of communities and also the bathymetric distribution of individual species are likely to involve a number of mechanisms that act during the larval stage. These mechanisms may include larval physiological tolerances to temperature and pressure, inherent larval behaviours and the availability of food. Factors that limit depth of occurrence may place limits on the invasion of deeper water by shallow water species, but in most deep-sea animals, such limiting factors for individual species are unknown (Tyler & Young, 1998). In addition, there are only a few physiological experiments on early life-story stages of deep-sea benthic animals. (Dayton et al., 1982; Young & Tyler, 1993; Young et al., 1996ab, 1997; Tyler & Young, 1998). Tyler & Young (1998) examined temperature and pressure tolerances of the dispersal stages of congeneric species of echinoids with different bathymetric distributions, and it was inferred that physiological tolerances of the larvae influenced the adult distribution. Young et al. (1996b) experimented with early embryos of 7 littoral species of tropical echinoids from Hawaii and the Bahamas and 3 bathyal species from the Bahamas. In every case, embryos tolerated pressures greater than those of their adult normal distributional ranges, but at temperatures found in shallow water. This suggests that pressure does not set actual depth limits for most species and would not prevent recruitment or invasion of depths as great as 2000 m. Sewell & Young (1999) concluded that the geographic distribution of the echinoid Echinometra lucunter does not appear to be limited by the temperatures at 94
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University of Southampton Research
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Graduate School of the National Oce
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UNIVERSITY OF SOUTHAMPTON ABSTRACT
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Marthasterias glacialis (ECHINODERM
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Acknowledgments I know everybody sa
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Prière de l’étoile de mer Seign
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species of asteroid Patiriella para
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embryonic tolerances could determin
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dispersed over great distances and
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lecithotrophic development. The pre
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al., 1997). In a review (Vrijenhoek
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Although larval dispersal and settl
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larvae of shallow water echinoids f
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few hours, whereas other species su
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een defined as a unique sequence of
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therefore a developing form may wel
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adults” that have the definitive
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The dipleurula is the hypothetical
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among tunicate tadpoles, sponge and
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Fig.2.4. Bipinnaria larvae of the a
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In marine invertebrates there is a
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independent of habitat or mode of n
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whether juveniles derived from larv
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and the northern Mediterranean have
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Wares (2001) performed phylogenetic
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Fig. 3.2. A. Marthasterias glaciali
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3.2.2- Temperature/pressure effects
Page 55 and 56: Pressure was applied using an Enerp
Page 57 and 58: Fig. 3.7. Bippinaria larvae of Mart
Page 59 and 60: X Data were abnormal. At 150 and 20
Page 61 and 62: X Data all the embryos were abnorma
Page 63 and 64: X Data blastulae, at 200atm 90% of
Page 65 and 66: 50atm more than 90% of embryos were
Page 67 and 68: Those data (Young et al., 1997; Ped
Page 69 and 70: Percentage of individuals swimming
Page 71 and 72: that settling invertebrate larvae d
Page 73 and 74: CHAPTER FOUR- REPRODUCTIVE FEATURES
Page 75 and 76: In 1973, Vance proposed a theoretic
Page 77 and 78: Species Volume Energy Dev Class Ref
Page 79 and 80: 4.1.2- Body Size The reproductive o
Page 81: Species Depth of max. Depth range (
Page 84 and 85: arm, and the minor radius (r), from
Page 86 and 87: From Eqs.1 and 3 we obtain the esti
Page 88 and 89: Data on maximum body size, maximum
Page 90 and 91: 250 200 Body size (mm) 150 100 50 0
Page 92 and 93: Fig. 4.7. Hierarchical cluster anal
Page 94 and 95: (Hymenaster membranaceus Thomson).
Page 96 and 97: gamete production at low population
Page 98 and 99: varies depending on the vitellogeni
Page 100 and 101: size, high fecundity, small egg siz
Page 102 and 103: strategy described by Winemiller an
Page 104 and 105: It seems that evolutionary features
Page 108 and 109: which normal embryonic/larval devel
Page 110 and 111: Larval dispersal from eight populat
Page 112 and 113: These results are very important si
Page 114 and 115: possibility. The opportunistic spec
Page 116 and 117: hypothesis that the Mesozoic and ea
Page 118 and 119: Barnes, H. and H.T. Powell. 1951. T
Page 120 and 121: Chester, C.M. 1996. The effect of a
Page 122 and 123: Crisp, D.J. 1978. Genetic consequen
Page 124 and 125: David, B., A. Guille, J-P. Féral a
Page 126 and 127: Grant, A. 1983. On the evolution of
Page 128 and 129: Inaba, D. 1934. On some holothurian
Page 130 and 131: of the 6 th International Echinoder
Page 132 and 133: Lieberkind, I. 1926. Ctenodiscus au
Page 134 and 135: McEdward, L.R. and S.F. Carson. 198
Page 136 and 137: Minchin, D. 1987. Sea-water tempera
Page 138 and 139: Pawson, D.L. 1976. Some aspects of
Page 140 and 141: Pingree. R.D., B. Sinha and C.R. Gr
Page 142 and 143: Savidge, G., H.J. Lennon, and A.D.
Page 144 and 145: Shilling, F.M. and D.T. Manahan. 19
Page 146 and 147: Turner, R.L. and J.M. Lawrence. 197
Page 148 and 149: Vickery, M.S. and J.B. McClintock 2
Page 150 and 151: (Eds.): Reproduction Genetics and D
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