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diameter) that develop into lecithotrophic larvae and may spend several weeks in the plankton before settlement. The results showed that the patterns of buoyancy of eggs and swimming velocity of larvae should initially facilitate dispersion in P. tesselatus. Scheltema (1971) introduced into the scientific literature several expressions that explicitly address larval dispersal abilities, recognizing the need for terms that describe dispersal potential. Teleplanic (tel= far, planos= wanderer) are those larvae with planktonic periods exceeding two months and possibly enduring a year or more. Teleplanic larvae are common amongst architectonid and cymatiid gastropods (Scheltema, 1966, 1988), bivalve veligers (Scheltema & Scheltema, 1984), spionid and chaetopterid polychaetes (Scheltema, 1986b, 1988, 1992), sipunculan pelagosphera (Scheltema & Hall, 1975), and lobster phylosoma (Phillips & Sastry, 1980). Teleplanic dispersal is also known to occur in enteropneust tornaria (Scheltema, 1987), phoronid actinotrochs, brachyuran zoea and megalopae, and echinoderm bipinnaria, auricularia (Scheltema, 1986b), and ophioplutei (Hendler, 1991). Distributions of teleplanic larvae suggest that they are capable of transoceanic dispersal in both the Atlantic (Scheltema, 1968, 1971) and the Pacific Oceans (Scheltema, 1986b, 1988). The term actaeplanic (actaeos= coastal, planos= wanderer) was introduced in 1989 to refer to shoreline larvae with planktonic periods from one week to less than 2 months. About 70 % of temperate sublittoral species are included in this category; most of them have planktonic development times of 4 to 6 weeks (Levin & Bridges, 1995). Anchiplanic (Anchi= near, planos= wanderer) refers to “nearby wanderers” larvae, which remain in the plankton from a few hours to a few days. This abbreviated dispersal ability can be found in almost every phylum, and is particularly common 35
among tunicate tadpoles, sponge and bryozoan larvae, and some coral planulae, as well as certain polychaete families. The non-planktonic larvae are at the end of the spectrum. This kind of larva is considered Aplanic (a= without). Examples of aplanic larvae include forms that emerge from the adult with the capability to settle, but also include some lecithotrophic larvae in which development occurs completely during encapsulation or while crawling on the seabed, as happens in some corals (Gerrodette, 1981; Fadlallah & Pearse, 1982). 2.5. Larval types of Asteroids The class Asteroidea includes seven orders and 34 families of echinoderms incorporating approximately 1800 species (Clark & Downey, 1992; Hendler et al., 1995). Asteroids have basically two characteristic larval types: bipinnaria and brachiolaria (Fell, 1967). In addition, there are two more larval forms that are derived from the planktotrophic larvae: yolky brachiolariae and barrel-shaped larvae (Young, 2002). Ultimately some species do not have a larval stage and undergo direct development via a mesogen (Fell, 1967; Oguro, 1989; Chia & Walker, 1991; Chia et al., 1993; McEdward & Janies, 1993; McEdward & Miner, 2003). 2.5.1. The Bipinnaria The bipinnaria is a pelagic, feeding larva with a complex body form characterized by the bilateral arrangement of the pre- and post- oral ciliated, swimming and feeding bands that are originated on the arms (McBride, 1914; Kume & Dan, 1968) (Fig. 2.4.AB). The ovoid body has two ventral folds (oral and anal hoods) and multiple lateral lobes. Hollow extensions of the body wall form elongate bipinnarian arms that contain blastocoelic space and are not supported by calcareous 36
Page 1 and 2: University of Southampton Research
Page 3 and 4: Graduate School of the National Oce
Page 5 and 6: UNIVERSITY OF SOUTHAMPTON ABSTRACT
Page 7 and 8: Marthasterias glacialis (ECHINODERM
Page 9 and 10: Acknowledgments I know everybody sa
Page 11 and 12: Prière de l’étoile de mer Seign
Page 13 and 14: species of asteroid Patiriella para
Page 15 and 16: embryonic tolerances could determin
Page 17 and 18: dispersed over great distances and
Page 19 and 20: lecithotrophic development. The pre
Page 21 and 22: al., 1997). In a review (Vrijenhoek
Page 23 and 24: Although larval dispersal and settl
Page 25 and 26: larvae of shallow water echinoids f
Page 27 and 28: few hours, whereas other species su
Page 29 and 30: een defined as a unique sequence of
Page 31 and 32: therefore a developing form may wel
Page 33 and 34: adults” that have the definitive
Page 35: The dipleurula is the hypothetical
Page 39 and 40: Fig.2.4. Bipinnaria larvae of the a
Page 41 and 42: In marine invertebrates there is a
Page 43 and 44: independent of habitat or mode of n
Page 45 and 46: whether juveniles derived from larv
Page 47 and 48: and the northern Mediterranean have
Page 49 and 50: Wares (2001) performed phylogenetic
Page 51 and 52: Fig. 3.2. A. Marthasterias glaciali
Page 53 and 54: 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
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varies depending on the vitellogeni
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size, high fecundity, small egg siz
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strategy described by Winemiller an
Page 104 and 105:
It seems that evolutionary features
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strategy stablished by the Winemill
Page 108 and 109:
which normal embryonic/larval devel
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Larval dispersal from eight populat
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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
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David, B., A. Guille, J-P. Féral a
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Grant, A. 1983. On the evolution of
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Inaba, D. 1934. On some holothurian
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of the 6 th International Echinoder
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Lieberkind, I. 1926. Ctenodiscus au
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McEdward, L.R. and S.F. Carson. 198
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Minchin, D. 1987. Sea-water tempera
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Pawson, D.L. 1976. Some aspects of
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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
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Turner, R.L. and J.M. Lawrence. 197
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Vickery, M.S. and J.B. McClintock 2
Page 150 and 151:
(Eds.): Reproduction Genetics and D
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