Spotfin Croaker, Roncador steransi
The Spotfin Croaker, Roncador steransi, whose common Spanish name is roncador manchadoa, is a species in the Croaker or Sciaenidae Family, known collectively as berrugatras and corvinas in Mexico. Globally, there are only one species in the genus Roncador, and it is found in Mexican waters of the Pacific.
The Spotfin Croaker has a high, elongated body. They are a silvery color with blue-gray metallic above, brassy sides and a pale silvery belly. The sides have faint undulating lines that follow the scale rows. There is a large black blotch at the base of the pectoral fin for which they are named. They have black gill chambers. The head has a blunt overhanging snout with a recessed mouth on the underside. They do not have chin barbells, however the snout has ten pores and the chin has five pores. The anal fin has two spines and 8 rays with the second spine being slender and approximately 75% of the first ray; the caudal fin is slightly concave; the first dorsal fin has 10 spines and the second dorsal fin has one spine and 24 to 28 rays. They have 24 to 28 gill rakers and are covered with rough scales.
In Mexican waters the Spotfin Croaker has a limited distribution being found from Magdalena Bay northward along the central and northwest coasts of Baja and there is a report that there is an isolation population living in the Guaymas area along the coast of the mainland.
The Spotfin Croaker is found demersal in sandy bays and in the surf zone near rocks at depths up to 65 feet. They reach a maximum length of 70 cm (27 inches). They are very similar to a series of silvery croakers but they are the only one with a very large black blotch at the base of the pectoral fin.
They are caught primarily on cut bait (clams, squid, mullet, mussels, etc.) with small hooks and bottom rigs and viewed to be excellent table fare.