FISH and OTHER COMMERCIAL Sciienids on the TEXAS COAST
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NATURAL HISTORY AND CONSERVATION OF REDFISH AND OTHER COMMERCIAL SCIiENIDS ON THE TEXAS COAST B.v.TOHN C. PIDARRON 'l'empOfal'Y assi.~tant, United Siaies Bureau of jl'i.~hel"ies ~ CONTENTS Page Introduction_____________________________________________________________________ 130 General problem_ _______________________________________ _______________ ______ 130 Aim of the investigation_________________________________ 131 Description of Texas coast. ____________________ ______________________ ___________ 131 ~ethods__________________________________________________________________________ 136 Area of study_____________________________________________ __ __________________ 136 Sampling of fish population ____________________________ __ __________ _____ __ _____ 137 Collecting gear___ __ ______________________________________ ___________________ 138 Natural history of the redfish (Scimnops ocellatus) ___________________________ ___ __ 1:39 Description of adult_ _______________________ _________________________________ 1:39 Description of young -_____ 1:39 Spawning and early distribution of young_ _____ _____________________ _____ ___ __ ___ 142 Growth and age_ _________________ __ ____________ __________________________ _ _ 145 Seasonal distribution and movements -- _ -- _____ __ __ _ 152 Size and age at maturity - _________ 153 Food habits_ __________________________ ________________________________ ________ 154 Commercial considerations - ______ __ __ 155 Summary -- -_________ 157 Natural history of the black drum (Po(Jonias cromis)__________________________________ 157 Description of adult -- -_________ 157 Description of young --- __ -__ __ __ 158 Spawning and early distribution of young - ______ __ __ lUO Growth and age_______________________________________________________ 165 Size and age at maturity_ __ __ __ _______________________________ _ -- _____ 170 Seasonal distribution and movemellts_ _ __ _______________ __ _ __ _ __ ____ __ __ ____________ __ __ 171 Food habits - -- - -- ------- -- --------- 174 Commercial considerations - _- - - - -- --------- -- --- -- - -- ---- -- -- ----- -- -- -- -- - -- - - - - - _ 175 Slllnnlary -------------------- -- --- -- ---- -- ------------ -- - -- --- -- - - - __ 178 Natural history of the spotted trout. (Cynoscion neblllosllsL --- -- ------ -- - -- ----- --___ _ 178 Description of adult. ------------------------------------- -- ------- __ __ 178 Description of young --- -- --------------------------- -- ------ -- - --- _- _ __ 178 Spawning IUld carly distribution of young- - -- -- -- - - 180 Growt.h and age ----------------_ 182 Size lmd age at maturity ------ -- ---------- -- - -- ---- --- -- -- ------ -- -- -_ -- ____ IS\) Seasollal distribution llnd movemcnts_ -------- -- ----- -- --- -- - -- - - - -- -- ------- -- --- -- --- __ _ l!lO Food habits - --- - - - ------- -- -- -- ---------- -- ---- -- - -- -- ------- -- -- 191 Commercial considemt.ions__ -_-- __ ------------------- -- - --- -- -- -- -- -- - -- --- - -- --- -- -- -- 192 Summary ~ - - __ ------ -- - -- -- -- -- -- - -- -- -- - -- -- 1\)'\ 129 130 BULLETIN OF THE BUREAU OF FISHERIES Page Natural history of the croaker (Micropogon undulatus)_________________________________ 194 Description of adult ._ ________ 194 Description of young .. ________________ 194 Spawning and early distribution of young_ _______________________________________ 196 Growth and age______________________________________________________________ 198 Size and age at maturity_______________________________________________________ 201 Seasonal distribution and movements__ __________________________________________ 202 Food habits ~______________________________________________ 203 Commercial considerations_ ____________________________________________________ 203 Summary____________________________________________________________________ 203 Natural history of the spot (Leiostomus xanthurus) ____________________________________ 204 Description of adult_ __________________________________________________________ 204 Description of young ._ __________________ 204 Spawning and early distribution of young_ _______________________________________ 204 Growth and age . __ . .. 206 Size and age at maturity .. _______ ________ ____ 209 Seasonal distribution and movements .. _____ 209 Food habUs__________________________________________________________________ 210 Commercial considerations_ ____________________________________________________ 210 Sulllmary____________________________________________________________________ 210 Summary of recommendations_ __ ____ _____ __ ___ ___________ _____________________ __ 211 Bibliography_____________________________________________________________________ 214 INTRODUCTION GENERAL PROBLEM In the summer of 1925 the United States Bureau of Fisheries, heeding a demand from Texans for more specific information as to the actual status of their coastal marine fisheries, conducted a short survey of those fisheries. The results of the study were presented in a Preliminary Report on the Marine Fisheries of Texas, by Higgins and Lord (1926), in which the character of the fisheries was discussed in the light of their past and present yields. A logical recommendation given in this report was for the immediate initiation of biological investigations that would include primarily extended study of the life histories of various marine food fishes of the State. Having complete control of its commercial fisheries, Texas has been alarmed for some time as to the possibility that serious depletion of its shore fisheries would occur before any steps could be taken to insure a permanent supply of food fish. Many prohibitive laws have been passed, unfortunately, without sufficient knowledge of the life histories of the fish to allow rational conservation of the fish stock as well as intelligent utilization and development of the fisheries. The people most interested in the future welfare of the marine resources of Texas are beginning to realize that 11 fundamental prerequisite for adequate fisheries legislation is an accurate, unbiased knowledge of the life histories of the food fish entering into the fisheries. NA'l'UHAL HIS'l'ORY OF REDFISH, E're., 01<' 'l'EXAS 131 AIM OF THE INVESTIGATION 1 The natural histories of the three leading food fishes of coastal Texfis-the redfish (Sciacnops ocellatus), the black drum (Pogonias cromis), llnd the spotted sea trout (Cynoscion nebulosus)-hl1ve been little understood in any section of the distribution of these species. Along the Texas COllst serious debates often arise as to the habits of the redfish, drum, and spotted trout, with special reference to the location of spfiwning areas and the distribution of young and adult fish. Reliable information concerning the life histories of these most valued shore fishes is of much interest, both from a popular standpoint and the point of view of those individuals that are intrusted with the conservfition of the natural resources of Texas. To furnish this sound basis for conservation, the first of a series of scientific fishery investigations was undertfiken to ascertain, primarily, the location of the spawning grounds, rate of growth, seasonal distribution, and movements of the redfish, black drum, and spotted sea trout. As a result of the support of the Texas game, fish, and oyster commission, which consisted in furnishing a fishing boat and crew, various launches, as well as other equipment and services, the bureau is able to present the following paper, embodying the results and conclusions of 14 months' field observations and collections along the coast of TeXllS. These observations, conducted continuously from April, 1926, to .Tune, 1927, included studies on the natural history of the croaker (Micropogon undu latlls) and the spot (Leiostomus xenth1J,rus), fishes of secondary commercial importance in Texas but of considerable value along the Atlantic COllst. DESCRIPTION OF TEXAS COAST The entire coast line of Texas, from the mouth of the Sabine River in the north to the mouth of the Rio Grande in the south, extends along the Gulf of Mexico for nearly 400 miles. The great,er portion of the coast is bordered hy II chain of low, sandy barrier islands, which sepnmte the many coastlll bfiys and lagoons from the Gulf of Mexico and through which run the various passes that eonnect the inland waters with the Gulf. The coast line following the winding shores of these many bays, lagoons, and coves extends about 2,000 miles along the mainland. A central coastal section, extending, roughly, from Copano Bay on the north to Baffin Bay on the south, provides an extremely diverse system of intercoastal and Gulf waters. Many types of marine environment are to be found within this general area, in which the greater part of the field work centered and which, for the purposes of the investigation, appeared to satisfy the demand for an area of observation that would be representative of the entire coast line. -------------- 1 Appreciation and thanks are due to tho following individuals for assistance and mlvice, whieh enabled the investigator to r:rogress in his tusk moro rapidly than wonld have heen possible if their intorest and help had beenlaeking: Turner E. lIubby. former commissioner of the 'rexas game, fish, and oyster commission; William J. 'l'ucker, present commissioner of the Stato com" mission; C. W. Gibson, of the Lone Star Fish & Oyster Co., Corpus Christl, 'rex.; nobert E. Farley, deputy of the 'rexas game, fish, and oyster commission; Lawrenco Oates of