Fecundity and rate of embryonic development of the lobster, Homarus gammarus (L), off the coast of North Wales

Maturity, fecundity and reproductive potential of the European lobster (Homarus gammarus) in Ireland

“…Tully et al 63 Journal of the Marine Biological Association of the United Kingdom (2001) Campbell & Robinson, 1983;2, Perkins, 1971;3, Squires, 1970. Homarus gammarus: 4, Latrouite et al, 1984 (Iroise Sea); 5, Bennett, 1987 (Wales); 6, present study; 7, Bennett, 1987 (Yorkshire); 8, Hepper & Gough, 1978. not shown graphically) and power (y0.0044ÂCL 3.155 ) functions explained 70 and 65% (r 2 in Figure 2B) of the variance in the CL7fecundity relationship respectively. The lower exponent of the CL7fecundity power relationship of 3.15 was partially explained by the increase in egg weight with increasing body size (Figure 3).…”

Comparisons of size at maturity and fecundity of two Scottish populations of the European lobster, Homarus gammarus

“…However, fecundity was not statistically different between locations for a range of egg development (ESI) of 0.29-0.54. Previous studies have also failed to detect geographic differences in fecundity, including studies in Ireland (Tully et al, 2001), England (Bennett and Howard, 1987), Wales (Hepper and Gough, 1978) and France (Latrouite et al, 1984), indicating that H. gammarus fecundity appears similar over this geographic range. The size-specific fecundity relationships obtained in this study were power functions with exponents of 3.3 for the Hebrides and 3.6 for the Firth of Forth.…”

“…In contrast to the American lobster, the spawning cycle in the European lobster is not well understood and assumptions of annual or biennial spawning have been made (Latrouite et al, 1981;Tully et al, 2001), which may have influenced the estimated reproductive potential and obscured possible regional variations. The influence of temperature on the reproductive parameters of the American and European lobster, such as SOM, egg production, time of spawning, co-ordination of the moulting and spawning cycles, time of hatch, and egg attachment and incubation success is believed to be strong (Tully et al, 2001;Hepper and Gough, 1978;Aiken and Waddy, 1986;Waddy and Aiken, 1992). Therefore, knowing the period of spawning is of relevance to avoid biased estimates of the size-fecundity relationship and to allow for better comparisons of regional variations of reproductive potential.…”

Embryonic Development of the American Lobster (Homarus americanus): Quantitative Staging and Characterization of an Embryonic Molt Cycle

“…Therefore, we have used a morphometric index, the size of the screening pigment spot in the lateral eyes (the eye index of Perkins, 1972) as the basis for a percent-staging scheme. The eye index has been used as an indicator of developmental stage in a number of embryonic studies (Schuur et al, 1976;Hepper and Gough, 1978;Cole and Lang, 1980;Sasaki, 1984;Sasaki et al, 1986;Beltz and Kravitz, 1987;Beltz et al, 1990;Helluy and Beltz, 1990;Meier and Reichert, 1990).…”

“…The nineteenth century studies also tend to focus on early embryogenesis while providing little or no information about middle and late development in the egg, and the embryonic molt cycle. A deeper knowledge of lobster embryology could also provide more insight and understanding of studies that examine particular aspects of development, such as the influence of temperature on growth rate (Templeman, 1940;Perkins, 1972) population dynamics (Schuur et al 1976;Hepper and Gough, 1978) the chemical composition and calorific content of the eggs (Pandian 1970a, b;Sasaki, 1984;Sasaki et al 1986) or the differentiation of particular organs or systems, such as heart and gut (Burrage, 1978;Burrage and Sherman, 1979) and, again, nervous system.…”