larvae accounted for 54% of embryos at 16 h postfertilization, and 98% of larvae at 20 h postfertilization.
Mortalities during the initial growth stage from fertilized egg to the hatch out of trochophore
larvae (Stage 14) varied from 43% to 86%, with no correlation to temperature.
5h 16-cell 19h 32-64-cell 23h Blastula 43h Gastula Day 3 (56 h) Trochophore
Day 4 (104 h) Veliger Day 6 (133 h) Hatching Day 10 Competence Day 51 Metamorphosis Day 61 2.
and veligers were most abundant near the surface of the water (Ault 1985).
concepts: ciliary bands and the evolution of larvae in spiralian Metazoa.
Representatives of some phyla also share a trochophore
larval stage (e.
Most annelid larval forms, feeding or not, can be readily related to the trochophore
ground plan, which Nielsen (2001, 2004) defined as a larva bearing an apical tuft, a preoral ciliated band derived from trochoblasts (prototroch), an adoral ciliary zone, and postoral metatroch, gastrotroch, and telotroch, all of which bands consist of multiciliate cells with compound cilia.
This study analyzed, for the first time in Atrina maura, the influence of the origin (depth, tidal phases) and gross condition of broodstock in reproductive performance (number and size of released and fertilized eggs; number of trochophore
and veliger larvae) and larval performance (growth and survival).
are found in a number of spiralians, and the trochophore
is believed to be the ancestral larval type of the spiralians (lophotrochozoans) (Nielsen, 2004, 2005; Raff, 2008).
developed after exposure of fertilized eggs to dispersed oil (25 mg/L) or oil (100 mg/L; [F.
Much of the remainder of polychaete trochophores
, including epidermal epithelium of the hyposphere, the generative zone for metameres, the gut (whether functional in the trochophore
or not), derivatives of the mesoderm, and ingressing neurons of the cerebral ganglia, continue to develop during larval, metamorphic, and juvenile development as components of the definitive adult body (e.
Thus at least some palaeonemertean larvae appear to be modified trochophores