Development and Effect of Female Size on Egg and Juvenile Production in the Neogastropod Buccinum cyaneum from the Saguenay Fjord

Abstract

The size at sexual maturity, the developmental timing and biology, and the biochemical (protein, glycogen, and lipid) content of eggs and juveniles were determined in two female size groups of the buccinid Buccinum cyaneum. Males reach sexual maturity at a smaller size (27 mm in shell length) than females (37 mm). A total of 33 females spawned in the laboratory starting in November 1991. The egg capsules were concave, measured 6.3 mm in diameter, and contained between 300 and 1000 eggs measuring 240 μm in diameter. Between 1 and 10 embryos developed. The others underwent chromatin degeneration within 3–4 wk and became nurse eggs. Between 1 and 10 crawling juveniles emerged 9 mo later in July and August and measured 2.5 ± 0.3 mm in shell length. The number of eggs and developing embryos within egg capsules increased with the size of the female. However, the quality of the juvenile at hatching, both in size and in biochemical content, did not vary significantly with female size.