TY - JOUR
T1 - Effects of marine ciliates on survivability of the first-feeding larval surgeonfish, Paracanthurus hepatus
T2 - Laboratory rearing experiments
AU - Nagano, Naoki
AU - Iwatsuki, Yukio
AU - Kamiyama, Takashi
AU - Nakata, Hideaki
PY - 2000/1/1
Y1 - 2000/1/1
N2 - The contribution of ciliates as a food source to survival of first-feeding surgeonfish larvae, Paracanthurus hepatus, was examined in rearing experiments. The larvae were exposed to eight treatments; i.e. a tintinnid, Amphorellopsis acuta (1.0 × 104, 5.1 × 103 and 2.2 × 103 cells 1-1) and a naked ciliate, Euplotes sp. (1.3 × 104, 8.0 × 103 and 5.0 × 103 cells 1-1), plus two controls without ciliates. Highest survival of the larvae over the first 4-8 days was observed in the highest density of A. acuta. Rearing experiments also showed that the survivals of larvae fed with A. acuta were higher than those fed with Euplotes sp. Gut content analyses revealed loricae of A. acuta in the larvae. Although Euplotes sp. (lacking loricae) was never recognized in those larval guts, feeding on Euplotes sp. by larvae was confirmed using the ciliate labeled with fluorescent microspheres, implying that the feeding on naked ciliates by fish larvae has been overlooked. The results strongly suggested that both tintinnid and naked ciliates play important roles as alternative food sources to copepod nauplii by enhancing the survivability of fish larvae, especially those with a smaller mouth.
AB - The contribution of ciliates as a food source to survival of first-feeding surgeonfish larvae, Paracanthurus hepatus, was examined in rearing experiments. The larvae were exposed to eight treatments; i.e. a tintinnid, Amphorellopsis acuta (1.0 × 104, 5.1 × 103 and 2.2 × 103 cells 1-1) and a naked ciliate, Euplotes sp. (1.3 × 104, 8.0 × 103 and 5.0 × 103 cells 1-1), plus two controls without ciliates. Highest survival of the larvae over the first 4-8 days was observed in the highest density of A. acuta. Rearing experiments also showed that the survivals of larvae fed with A. acuta were higher than those fed with Euplotes sp. Gut content analyses revealed loricae of A. acuta in the larvae. Although Euplotes sp. (lacking loricae) was never recognized in those larval guts, feeding on Euplotes sp. by larvae was confirmed using the ciliate labeled with fluorescent microspheres, implying that the feeding on naked ciliates by fish larvae has been overlooked. The results strongly suggested that both tintinnid and naked ciliates play important roles as alternative food sources to copepod nauplii by enhancing the survivability of fish larvae, especially those with a smaller mouth.
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U2 - 10.1023/a:1004094825739
DO - 10.1023/a:1004094825739
M3 - Article
AN - SCOPUS:0001487322
VL - 432
SP - 149
EP - 157
JO - Journal of Aquatic Ecosystem Health
JF - Journal of Aquatic Ecosystem Health
SN - 0018-8158
IS - 1-3
ER -