Prostheceraeus crozieri

Prostheceraeus crozieri (Hyman, 1939) Fig. 7 Material examined. Campeche coast, Mexico • 1; Cayos sumergidos del Oeste; 20.4°N, 92.2°W; 18 m; 14 Sep. 2017; A. Gutiérrez leg.; CRPPY -0018 • 1; Cayo Arcas; 20.2°N, 92.0°W; 16.3 m; 20 Aug. 2018; A. Hernández leg.; CRPPY -0108. Distribution. Recorded in the east coast of Florida and the Florida Keys, Bermuda (Crozier 1917; Hyman 1939); Curaçao (Marcus and Marcus 1968); Jamaica, the Gulf of Mexico, and the Caribbean (Hyman 1952). New record for the coast of Campeche, Mexico. Description. Oval or circular-shaped body, 2.3 cm in length and 0.8 cm in width, with a semi-transparent white-beige background with transverse wavy black lines. The lines alternately end in a black spot or an orange blotch. Dorsal surface with white spots and a submarginal semi-transparent and marginal narrow white band (Fig. 7 A, C, D). Ventral surface creamy white (Fig. 7 B). Marginal orange tentacles long with black and white tips. Cerebral eye is distributed in two elongated clusters, each containing ~ 35 eyes (Fig. 7 A, C). The anatomy of the reproductive system agrees with that described by Hyman (1939). Remarks. The specimen from the Gulf of Mexico aligns with the description of Prostheceraeus crozieri provided by Hyman (1939). Newman et al. (2000) transferred both Pseudoceros crozieri Hyman, 1939 and Prostheceraeus zebra Hyman, 1955 to Maritigrella crozieri due to the presence of a tubular pharynx and the lack of uterine vesicles. Litvaitis et al. (2019) reclassified Maritigrella crozieri as Prostheceraeus based on the description and illustration of Prostheceraeus zebra by Hyman (1955). Biology. Prostheceraeus crozieri is documented as a primary consumer of the sea squirt Ecteinascidia turbinata. Although this ascidian species was prolific within the research areas, the occurrence of Prostheceraeus crozieri was limited.