Oral Gestation in the Marine Catfish, Galeichthys felis

Abstract

FOR four consecutive summers, 1928, 1929, 1930 and 1931, students of the Louisiana State University Summer Field Biology Laboratory at Grand Isle, Louisiana, studied the breeding habits of the six-whiskered marine catfish, Galeicktkys felis. In 1928, as records were made of the occurrence of this fish in the trawl hauls, it was noticed that Galeickthys felis is a mouthbreeder. In 1929, Elizabeth Foster began a study of the breeding habits of this fish. The following summer Rose Beeson continued the work; and in 1931, I made further observations and. have now organized the mass of data collected during the three summers. I wish here to make acknowledgment of the work done by Misses Foster and Beeson and to thank them for their generosity in permitting their observations to be used as a basis for further study of Galeickthys felis. To Doctor Samuel F. Hildebrand of the United States Bureau of Fisheries, also, I wish to express the appreciation of the laboratory for the courtesy he has extended to us. In August, 1930, he made some observations which proved beyond reasonable doubt that Galeichthys felis is a mouth-breeder. Upon learning of the study being made with the same catfish in this laboratory, he kindly transferred his notes to us. I also wish to thank Doctor Hildebrand for reading this paper and offering valuable suggestions for its improvement. Especially to Doctor Ellinor H. Behre, Director of the Laboratory at Grand Isle, do I wish to express my appreciation of her help and encouragement in this work. An abstract of this paper was published several years ago (Lee, 1931). Most of the material of Galeichthys felis used in this investigation was obtained by trawling in the bays and Gulf around Grand Isle, but some was gotten by seining and some by fishing with hook and line. Upon bringing up the trawl, the mouths of males carrying eggs or young were wrapped in cheesecloth and tied to prevent the fish from spitting out the offspring. Due to the confusion in the net and rough handling as it is brought into the boat, the catfish quite often throw out their eggs. However, if the net is brought up very carefully and the fish are not shaken out but removed by hand, few eggs are.lost. When the fish are handled as described, and their mouths'are full, the egg count per male is considered accurate. The desired measurements and dissections, if not made between trawl hauls, were made in the laboratory very soon after arrival from the trawling trip. Each catch was wrapped separately in cheesecloth to prevent mixing. Only fresh specimens were used for measurements. The fish being brought in were kept in closed containers to prevent drying. Upon arrival at the laboratory, the eggs were taken from the mouths of the males, counted and sometimes measured. Attempts were made to keep eggs alive by means described on a succeeding page. HABITAT AND ABUNDANCE