Egg and larval development of laboratory-reared gulf flounder, Paralichthys albigutta, and southern flounder, P. lethostigma (Pisces, Paralichthyidae)

• Published in: Fishery bulletin (Washington, D.C.) Vol. 93; no. 3; pp. 504 - 515
• Main Authors: Powell, AB, Henley, T
• Format: Journal Article
• Language: English
• Published: 1995
• Subjects: Marine; Paralichthys
• ISSN: 0090-0656

The egg and larval development of Paralichthys albigutta (gulf flounder) and P. lethostigma (southern flounder) are described from laboratory-reared and field-collected specimens. Paralichthys albigutta eggs and oil globules had a mean diameter of 0.87 mm (range: 0.84-0.90 mm) and 0.18 mm (range: 0.17-0.19 mm), respectively. Paralichthys lethostigma eggs and oil globules had a mean diameter of 0.91 mm (range: 0.84-0.96 mm) and 0.18 mm (range: 0.16-0.20 mm), respectively. Recently hatched P. albigutta larvae ranged from 1.8 to 2.2 mm in notochord length (NL) and P. lethostigma from 2.0 to 2.2 mm NL. Pigment on embryos and newly hatched larvae was relatively more developed for P. albigutta. Almost-paired and almost-contiguous ventral midline melanophores occurred on preflexion larvae of both species and remained throughout the larval stages. Pigment on the maxillary, vomer, dorsum of the mid-brain, lateral surface of the caudal area, lateral surface of gut, and extent of pigment along the ventral midline of the isthmus were used to separate laboratory-reared. P. albigutta from P. lethostigma. However, this pigment was less useful in separating field-collected material. The number of cranial spines appeared to be diagnostic in separating laboratory-reared early-preflexion larvae. Paralichthys lethostigma consistently had three cranial spines, whereas P. albigutta had less than three spines. The development of meristic characters was considered the most useful character in separating P. albigutta from P. lethostigma because at any given size P. albigutta was generally more developed than P. lethostigma.