LARVAL AND JUVENILE DEVELOPMENT OF THE CUBBYU PAREQUES UMBROSUS WITH NOTES ON THE HIGH HAT PAREQUES ACUMINATUSLARVAE

摘要

Larval and juvenile development of Pareques umbrosus is described from laboratory spawned and reared specimens. Eggs of P. umbrosus ranged from l.08 to l.38 mm diam- eter with a single, pigmented oil globule 0.23 mm diameter. Yolk-sac larvae averaged 2.82 mm NL and had heavy golden-green stellate chromatophores covering the trunk and tail in fresh specimens. Preserved larvae had scattered melanophores on the trunk, tail and yolk-sac. Transition to exogenous feeding occurred at 2.59 mm NL and melanistic pigmentation included a distinct band around the tail anterior to the tip of the notochord, another vertical swath from the dorsal finfold through the pectorals to the pelvic area, and a lateral stripe that extended from the snout through the eye to the cleithrum. Two preopercle spines appeared just prior to flexion at 4.67 mm SL. A continuous horizontal stripe the length of the trunk and tail first developed at about 8.l6 mm SL. Metamorpho- sis to the juvenile stage occurred between l0.00 and l5.00 mm SL. Juveniles averaging 30.5 nun SL had a characteristic 3-stripe color pattern, and a darkly pigmented first dorsal with a white trailing edge. The first dorsal was l.5 times longer than the body depth. The pigmented pelvic fin had white leading and trailing edges. All but the center longitudinal body stripe were narrower than the pupil in juveniles with 4 to 6-stripes. All stripes were narrower than the pupil when the adult 7-stripe pattern was developed by 4 l- 67 mm SL. Lab reared P acuminatus larvae of known-age were distinguished from P umbrosus by the presence of three distinct pre-operacular spines in flexion larvae, con- spicuous White leading and trailing edges on the first dorsal, and in juveniles by the extremely long first dorsal (~75/100 SL).