Captive breeding and early development of tank-reared lyretail anthias Pseudanthias squamipinnis (Peters, 1855): Assessments of hatching success, larval survival, and ontogeny

Abstract

The lyretail anthias Pseudanthias squamipinnis is distributed throughout tropical and subtropical coral reefs of the Indo-West Pacific, and it is considered a species of high commercial value in the marine ornamental trade due to its vibrant coloration. This study documented the reproductive behavior and spawning frequency of a tank-reared broodstock population of lyretail anthias, and investigated the optimal temperature and salinity for embryos and larvae cultivations. Furthermore, larval ontogeny was described based on a larviculture protocol incorporating copepod-based feeding. During the experimental period (March 31 to December 3, 2024), a total of 133 spawning events were recorded in a broodstock of 2 males and 2 females, with an average fecundity of 323 +/- 216 eggs per spawn and average fertilization rate of 70.86 +/- 2.33 %. Temperature showed a significantly negative correlation with fecundity (p < 0.01), but a significantly positive correlation with fertilization rate (p <= 0.001). In addition, spawning frequency was not significantly correlated with the lunar cycle during the experimental period (p > 0.05). The pelagic eggs were spherical and transparent (675.14 +/- 2.27 mu m in diameter), containing an oil globule (148.80 +/- 1.45 mu m in diameter) accompanied by several small droplets. The effects of five temperatures (21, 23, 25, 27, and 29 degrees C) and four salinities (25, 30, 35, and 40 ppt) on egg hatching rate and larval survival rate at 2 days post hatch (dph) were examined. The results indicated that P. squamipinnis eggs exhibited significantly higher hatching rates (87.50-98.96 %) when incubated at 25 ppt, regardless of temperature. In contrast, significantly higher 2-dph larval survival rates (59.38-64.58 %) were observed at 25 ppt and within the temperature range of 21 to 25 degrees C. The body length of newly hatched larvae was 1.62 +/- 0.01 mm. First feeding commenced at 3 dph, when the mouth gape height measured 247.74 +/- 4.08 mu m. Notochord flexion began at 15 dph, and metamorphosis was completed by 24 dph. By 55 dph, juveniles reached an average body length of 17.59 +/- 0.86 mm and exhibited a characteristic orange body coloration with a pink stripe extending from its eye. These findings offer valuable insights for developing captive breeding protocols for P. squamipinnis.