The most advanced yolked, migratory nucleus, and hydrated oocytes that were destined to be spawned
were identified for individuals on the basis of size-frequency distributions of whole oocytes (larger than 1000 microns).
The variability of egg diameter within batches spawned
from the same female over three consecutive spawning rounds and within diet treatments were determined.
In comparison, only 33% of the LD8:16 control females spawned
during the experimental period, one on 19 February, two on 23 February, and another on 25 February.
White seabass spawned
throughout the lunar cycle; although more individuals may have achieved reproductive readiness following the new moon, because 63% of mass spawning events occurred from the new moon until four days after the new moon.
To determine the time of spawning each day, we checked approximately every 15 minutes for fertilized eggs at the surface of the tank with a hand-held dipnet, usually beginning in mid- afternoon because the fish most often spawned
during the late afternoon or evening.
Mussel Densities and Proportion of Mussels that Spawned
Spawning females collected during 1999 and 2000 were either prespawning (stage 5a) and caught in the morning, or had recently spawned
(stage 5c) and were caught in the afternoon (Table 1).
On 7 April 2002, we observed that the yellow jacks spawned
at ~1705 hours (61 minutes before sunset local time) at Gladden Spit, less than 50 in south of the school of spawning permit.
In addition, when the total number of eggs spawned
is known, juvenile abundance can be used to assess overall variation in egg and larval survival.
These fish, collected between 2200 and 2359 hours during March 1997, all appeared to have recently spawned
Whitemouth croaker is a multiple spawner with an indeterminate annual fecundity; in other words, unyolked oocytes continuously mature and are spawned
throughout the reproductive season (Macchi, 1997).
from 7 April 1995 to 15 June 1995, at locations from the York River to 45 km offshore.