fuscus larvae is like that of other planktotrophic nudibranch larvae (Kempf and Willows, 1977; Perron and Turner, 1977; Chia and Koss, 1978; Bickell and Kempf, 1983; Hubbard, 1988), with a rapid rate of shell growth early in the larval period and a cessation of shell growth prior to competence in those few veligers
that achieved competency.
Fertilized eggs (1 hpf) were tested with densities between 888 and 2,341 ind/ml, and early benthic veligers
were tested with densities between 333 and 932 ind/ml (Table 1).
Velum of encapsulated veligers
of Petaloconchus (Gastropoda), and the problem of re-evolution of planktotrophic larvae.
Phototactic behavior in Haliotis mariae larvae was noticed from hatching to veliger
. Trochophores and veligers
were most abundant near the surface of the water (Ault 1985).
(1997b) of an early stage in the morphogenesis of the accessory salivary gland of encapsulated veligers
of Nucella lapillus shows clear parallels to the "ventral lip tubule" that I observed in late-stage larvae of C.
On day 4 after fertilization, veligers
are transferred from the larval culture tanks into nursery tanks, with a basal area of 7-10 [m.sup.2] for settlement.
We classified hatchlings as one of two types: veligers
(free-swimming lecithotrophic veligers
) or juveniles (post-metamorphic crawling juveniles with no velum).
The hatchery tank water was filtered every 48 h through with two consecutive screens according to the stages of larval development: 50 and 125 [micro]m (trocophores), 70 and 125 [micro]m (D-shaped veligers
), 125 and 250 [micro]m (umbo larvae), 250 and 500 [micro]m (pediveliger larvae), and 500 and 1,000 [micro]m (juveniles).
of the opistho-branch Philine aperta, with a shell length of about 270 [micro]m and a prototrochal cilium length of 50 to 55 [micro]m, maximum clearance rate was [approximately equal to]1.4 ml [d.sup.-1] (Hansen, 1991).
The number and size of released and fertilized eggs, number of veliger
larvae, and the survival and growth rate of larvae were significantly higher in January 2012 and correspond to low temperatures, high concentrations of food, high percent of ripe gonads, high- condition index (Cl), and low-muscle index (MI).
Egg capsules of the gastropod Concholepas concholepas (Bruguiere, 1789) that had been deposited in a continuous-flow aquarium at the Estacion de Biologia Marina Abate Juan Ignacio Molina, of the Universidad Catolica de la Santisima Conception, Chile, were kept in jars in aerated seawater at 14 [degrees]C, at the Campus San Andres of the same university, where veligers
hatched over several days.
At 120 [+ or -] 0.58 h after spawning, the veligers
that hatched were free swimming in the aquarium, moving vertically, and at times, retracting into the shell as if at rest (Fig.