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Comparisons of egg size, brood size and egg production per lifetime (fecundity per recruit) between lasus tristani from the Tristan da Cunha group of islands and l. lalandii from the west coast of southern Africa reveal distinct differences. Females of the continental species l. lalandii have smaller eggs, larger brood sizes and a greater fecundity per recruit than the insular species l. tristani. Greater egg production in l. lalandii implies that rates of larval mortality are likely to be higher in this species. A number of possible reasons may be involvedthese include differential predation rates on newly hatched and returning larval fonns, as well as losses induced by topographic forcing of currents by the Walvis Ridge. Vergelyking van eiergrootte, broeiselgrootte en eierproduksie per leeftyd (vrugbaarheid per rekruut) tussen lasus tristani van die Tristan da Cunha groep eilande en l. lalandii van die weskus van Suider-Afrika bring duidelike verskille aan die lig. Wyfies van die vastelandspesie l. lalandii het kleiner eiers, groter broeisels en groter vrugbaarheid per rekruut as die eilandspesie J. tristani. Groter eierproduksie by J. lalandii dui op 'n moontlik hoer larvale mortaliteitstempo vir hierdie spesie. Ellike redes daarvoor is moontlik-o.a. differensiele roof tempo's op pas uitgebroeide en terugkerende ]arvale vonns, asook verliese veroorsaak deur topografiese forsering van strome deur die Walvisrif.