Evaluation of larval quality of viviparous scorpionfish Sebastiscus marmoratus

Abstract

Abstract:We aimed to develop an acute test for larval quality in the viviparous scorpionfish (Sebastiscus marmoratus). Rearing experiments until day 13 post parturition were conducted to investigate the survival of larvae for 13 different batches, and tolerance to starvation of larvae was examined and expressed by the survival activity index (SAI). We also observed 5 the morphological characters, enzyme activity, and swimming behavior of larvae on day 0 and 1, followed by the correlation analysis between SAI. Larvae with high SAI (≥26) showed significantly higher survival on day 13 than larvae with low SAI, which confirmed that SAI is a reliable index that can be used to evaluate larval quality, similar to the former findings. The esterase activity (r=-0.713, P<0.01), swim frequency (r=-0.735, P<0.01) and swimming 10 speed (r=-0.588, P<0.05) of larvae on day 0 were significantly and negatively correlated with SAI. We conclude that enzyme activity and behavioral characters of larvae just after parturition can be a real-time index for evaluating the larval quality of this species.

Screening of enzyme activity for assessing the condition of larvae in the seven-band grouper Epinephelus septemfasciatus and devil stinger Inimicus japonicus

“…Additionally, some studies used the enzyme activity as an indicator for assessing the fitness and survival potential of fish larvae [2,5]. Supporting evidence was found by Ueberschär [2] who reported a tryptic activity measurement is useful in detecting unfavorable health condition of herring larvae.…”

“…Matsuo et al [5] also reported enzyme activity, esterase and alkaline phosphatase, can be a real-time index for evaluating the quality of viviparous scorpionfish larvae. Although Araujo et al [4] did not find correlation between enzyme activity and survival in Japanese flounder larvae, they observed whenever esterase and phospholipase fluorescence intensities were low, survival and growth of larvae were also low.…”

“…Further experiments should be conducted to determine whether the enzyme activity measurement can be a real-time biomarker for assessing the condition and/or quality of seven-band grouper and devil stinger using different batches at the same rearing conditions as revealed in the viviparous scorpion fish [5].…”

“…Enzyme activities of larvae were performed on individual larvae according to the highly sensitive fluorescence method of Ueberschär [2] with slight modifications after Matsuo et al [5]. Seven band grouper and devil stinger larvae were individually homogenized in 1 ml of 35 ppt artificial seawater using a sonicator (Sonifer 150, Branson, CT, USA).…”

“…Enzyme activity measurements using fluorescence technique is an advantageous method for estimating nutritional condition and stress of marine fish larvae because this technique can be done into the daily routine work in fish hatcheries and it requires a short period for determining [1][2][3][4]. Recently, Matsuo et al [5] reported that enzyme activity can be applied as a real-time biomarker for evaluating the larval quality in viviparous scorpionfish Sebastiscus marmoratus, however, not much is known whether this method is applicable for the diagnosis of oviparous fish larvae.…”