196 BULLETIN OF THE BUREAU OF FISHERIES 



ventrals are inconspicuous. The pigmentation is quite distinctive and helps to 

 identify the larval and post-larval croakers from larval and post-larval redfish 

 and black drum. Two very small chromatophores are at the base of the anal fin — 

 one generally between the first and second soft rays, the other directly posterior to 

 the last ray. The presence of these two markings seems to be constant in all speci- 

 mens examined, up to a length, at least, at which little doubt exists as to the correct 

 fin-ray count. Three to five small chromatophores lie posterior to the anal fin 

 along the ventral edge of the caudal peduncle. No dorsal chromatophores are 

 evident. (See fig. 33.) 



At a length of 11 millimeters a croaker has all rays in the vertical fin distinct, 

 with the usual count of II-8 for the anal and X, 1-29 for the dorsal. The fin fold 

 has disappeared, and the caudal fin is now considerably produced, a condition that 

 at once separates the species from the spot (Leiostomus xanthurus). Pectorals and 

 ventrals are distinct but not prominent. The ventral chromatophores may or may 

 not be present, but usually are, with the addition of several smaller ones at the base 

 of the caudal fin. Teeth and opercle spines are well developed. (See fig. 34.) 



When Texas croakers reach a length of about 30 millimeters (1.1 inches), they 

 closely resemble a 30-millimeter specimen described by Welsh and Breder (1923, 

 p. 182), and their description is given in part. (See fig. 35.) 



A croaker 30 millimeters long has the spiny armature of the head strongly 

 developed, the mandibular barbels are in evidence, and the shape of the body ap- 

 proaches that of the adult. The caudal has a flowing extension of the lower rays, 

 the longest ray being about equal to the length of the head. The color (in preserved 

 examples) is pale throughout, punctuated with groups of brownish chromatophores 

 in regular rows, 8 on the dorsal line from head to base of caudal, 8 to 10 on a line from 

 the opercular flap to caudal, a less distinct row lying between these. (In Texas 

 specimens the dorsal row always appears the most pronounced.) The snout, pre- 

 maxillary, tip of spinous dorsal, base of anal, and base of caudal rays are punctulate 

 with brownish. The adult color pattern is assumed gradually after a length of 3 

 centimeters is reached, but the fish retains its greatly lengthened caudal fin until a 

 much larger size. 



SPAWNING AND EARLY DISTRIBUTION OF YOUNG 



Along the coast of Texas the croaker ( Micropogon undulatus) spawns in the late 

 fall in the open Gulf of Mexico near the mouths of the various passes that lead into 

 the shallow bays and lagoons. Together with the spot {Leiostomus xanthurus) this 

 species greatly outnumbers in natural abundance the other members of the Scisenidae; 

 and, as a result of this abundance, particularly of young, observations on the spawning 

 and distribution of larval and post-larval fish were clear cut and informing. 



Soon after the first larval redfish had been discovered in the vicinity of Aransas 

 Pass, Tex., in October, 1926, a deluge of larval croakers filled the pass on each incoming 

 tide. The concentration of the young fish was most remarkable. Thousands were 

 obtained in a short haul with a sUk tow net in the deeper waters of the pass itself 

 and thousands more were obtained along the Gulf beach adjoining the pass by means 

 of a small minnow seine hauled along the surf line in a few feet of water. (See 

 Table 27.) , 



