Nurse egg consumption and intracapsular development in the common whelk Buccinum undatum (Linnaeus 1758)

Table 1 Developmental periods for intracapsular development in B. undatum from the south coast of England at 6 °C

Ontogenetic stage	Mean time in days spent at each stage (individual)	Time at developmental stage in days (whole egg mass)	Mean size (mm ± SD)	Mean size variation within one capsule (mm)^a	n	n (capsules)
Egg	49	0–56	0.23 (±0.01)	0.04	3,235	142
Trochophore	2	42–56	0.32 (±0.02)	0.01	19	12
Early veliger	5	42–56	1.46 (±0.15)	0.33	121	15
Veliger	18	42–77	1.65 (±0.17)	0.27	97	17
Pediveliger	18	70–98	1.91 (±0.32)	0.42	144	20
Pre-hatching juvenile	44	91–140	2.15 (±0.29)	0.38	74	14
Hatching juvenile	n/a	133–140	2.43 (±0.39)	n/a	102	n/a

Mean size at each ontogenetic stage is displayed (mm). Means are determined as an average of n measurements; n dictates total number of individuals measured. n (capsules) dictates number of capsules individuals were measured from and that were examined at each stage. Where n/a is stated, value was inapplicable or not determined
^aOnly capsules with 2 or more individuals included

ISSN: 1438-3888