Checklist of ascidians (Chordata, Tunicata) from the southern Gulf of Mexico Author A. Palomino-Alvarez, Lilian Author Moreira Rocha, Rosana Author Simoes, Nuno text ZooKeys 2019 832 1 33 http://dx.doi.org/10.3897/zookeys.832.31712 journal article http://dx.doi.org/10.3897/zookeys.832.31712 1313-2970-832-1 961F1299F1A3432794B315609F6F5A65 961F1299F1A3432794B315609F6F5A65 Pyura sp. Material examined. CAGoM-0129, CAGoM-0128, CAGoM-0134, B10, 11 m, 17-06-2017, leg. L. Palomino-Alvarez; CAGoM-0160, CAGoM-0162, CAGoM-0146, Pro 1, 7 m, 26-05-2015, leg. L. Palomino-Alvarez. Remarks. Specimens were compared with Panamanian specimens and are similar to a new species being described (Skinner et al. in press). In Yucatan peninsula they are 9-10 cm long, and were found mainly on coral reefs. Oral tentacles are more numerous (43-58) and one of the specimens had the following vessel formula: E 11 (28) 9 (28) 6 (34) 6 (36) 5 (33) 5 (31) 6 LD 3 (30) 5 (28) 5 (27) 6 (32) 6 (30) 6 (22) 10. All other characters were within the variation found in Panama.