Download (3398Kb) - ePrints Soton - University of Southampton

Those data (Young et al., 1997; Pedrotti, 1990) suggest that such embryos and
larvae could colonise the deep-sea under the warm deep-sea conditions that prevailed
in the late Mesozoic or early Cenozoic (Menzies et al., 1973; Hessler & Wilson,
1983). In the North Atlantic, Tyler & Young (1998) examined the temperature and
pressure tolerances of embryos and larvae of the shallow water species Echinus
esculentus Linnaeus, shallow and bathyal populations of E. acutus Linnaeus and
lower bathyal populations of E. affinis (Linnaeus). Embryos and larvae of both E.
esculentus and E. acutus were unlike the Mediterranean species, developmental
arrests and abnormalities did not increase with lower temperatures. Embryos of E.
acutus var. norvegicus from the bathyal zone tolerated a significantly broader range of
pressure and temperature than did embryos of E. acutus from shallow subtidal habitats
and also developed more rapidly at lower temperatures, suggesting that E. acutus is a
very plastic species and may be currently in the process of invading the deep-sea by
slowly adapting to increased pressure.
Source d.f. SS MS F p
Pressure (P) 4 12.693 2.6675 195.23 < 0.001
Temperature (T) 3 14.239 7.7764 552.67 < 0.001
Species (S) 1 1.526 1.971 110.69 < 0.001
P*T 12 6.453 0.0796 56.43 < 0.001
P*S 4 1.63 0.04351 24.12 < 0.001
T*S 3 1.63 0.7820 47.17 < 0.001
P*T*S 12 0.087 0.1132 7.57 < 0.001
Error 80 8.75 0.0134 - -
Table 3.1. Three-way analysis of variance for proportion of Asterias rubens and
Marthasterias glacialis that developed abnormally after 48 h of incubation.
66