![]() Ingestion rate increased with ration at 2 and 5 inds/mL but was not significantly affected by ration at 10 inds/mL. d−1, but larvae held at 2 and 5 inds/mL had significantly higher ingestion rates than those stocked at 10 inds/mL at 40×103 and 100×103 cells. ![]() It was not significantly affected by stocking density at 5×103 and 20×103 cells Ingestion rate ranged from 2×103 to 29×103 cells There was no significant effect of ration on percent survival at 2 and 5 inds/mL, but survival decreased with increasing ration at 10 inds/mL. Percent survival over the experiment duration (23 d) ranged from 7% to 56% in the various treatments and generally decreased with increasing stocking density. d−1 at 2 and 5 inds/mL, but decreased with increasing ration at 10 inds/mL.Growth rate increased with increasing ration up to 40×103 cells d−1, and was significantly higher at 2 and 5 than at 10 inds/mL at 40×103 and 100×103 cells.d−1, was significantly higher at 5 than at 2 inds/mL at 20×103 cells.It increased with stocking density at 5×103 cells Growth rate ranged from 2.15 to 3.85 μm/d in the various treatments. All three measurements were significantly affected by stocking density, ration, and their interaction. (Tahitian strain, TISO clone) were assessed. d−1) on growth, survival, and ingestion rate of larval geoduck clams Panopea generosa fed Isochrysis sp.The combined effects of initial stocking density (2, 5, 10 individuals /mL) and feed ration (5×103, 20×103, 40×103, 100×103 cells © 2018 National Shellfisheries Association. globosa from the embryonic stage to early juvenile stages. This is the first description of the development of P. The results demonstrate that highly uniform larvae sizes can be obtained from spawning runs in controlled environmental conditions. globosa is smaller than that of SL (SH = 0.875, SL = -2.20). The linear relationship between SL and SH indicates that the rate of SH growth during larval development of P. The growth of SH and SL were best described by a linear function of time (T = days) from fertilization to the pediveliger stage (SL = 12.04 T + 81.40 and SH = 10.69 T + 67.33). Umbo growth was apparent 7 days after fertilization, and pediveliger larvae (355.36 ± 20.99 μm SL and 313.64 ± 21.24 μm SH) developed 21 days after fertilization. Veliger larvae (146.36 ± 17.54 μm SL and 121.78 ± 15.96 μm SH) were observed 43 h after fertilization. Trochophore larvae (94.80 ± 0.74 μm SL and 82.92 ± 4.69 μm SH) were observed 17.5 h after fertilization. Fertilization and meiosis were confirmed by single membrane formation (after ∼5-10 min) and extrusion of the first polar body (after ∼15-20 min), respectively. Gametes were obtained from wild ripe broodstock and fertilized under controlled conditions (22.15☌, 35‰, pH8.4). The embryonic and larval developmental stages of the geoduck clam Panopea globosa were described, and the size at different ages post-fertilization were evaluated using both shell length (SL) and shell height (SH).
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