Standard length-total length relationships of gulf menhaden, Brevoortia patronus Goode, bay anchovy, Anchoa mitchilli (Valenciennes), and Atlantic croaker, Micropogon undulatus (Linnaeus), from Galveston Bay.

B. patronus, A. mitchilli and M. undulatus were collected, and standard length (SL) and total length (TL) were obtained. Linear regression lines were fitted to the length data by the method of least squares, and the correlation coefficient (r) and the mean square deviation from regression were calculated. The SL-TL conversion equation for menhadens was TL=0.62044 + 1.25323 SL, and for anchovies it was TL=0.22391 + 1.20634 SL. Unlike the other 2 species, the SL-TL conversion equation for the croakers changed with body length; the relative length of the caudal fin decreased as body length increased. Three separate regression lines were calculated for the 3 size groupings of Atlantic croaker: TL=1.21592 + 1.26753 SL for fish 28-95 mm SL, TL=9.70548 + 1.17538 SL for fish 102-159 mm SL, and TL= 19.88505 + 1.10952 SL for fish 168-255 mm SL.