Calendario Ictiológico de San Antonio

The rocky shore of Ensenada Panul at the North of the Port of San Antonio, was sampled monthly using a trammel net, in order to identify the habitat species and determine some relation concerning their abundance and their yearly cycle of arrival. Tentatively the total, relative abundance of every species has been established. Three quantitative methods were applied: 1.- The Warfel and Merriman method of yearly score. The most representative species are: A. punctatus; H. chilensis; S. oculatus; M. chilensis; Ch. variegatus. During a 10 month period, using monthly samplings, a total of 441 specimens were collected; 238 during the day and 203 at night. Of the total of 441 specimens 378 belonged to the previously mentioned species. The number of species captured during the daytime were 20; 11 of these were also captured in the night hauls. The main day species is A. punctatus, an Herbivorous fish; 17 species were exclusively represented in the night captures. The dominant species of the habitat at night is S. oculatus, a carnivorous fish. The greater species affinity is found at the end of the summer and the beginning of winter, with an intermixing group in springtime. 2.- With the percentage method three types of abundance curves were found: Type I with a maximum between May–June; Type II with a maximum between March–September (with A. punctatus a unique representative species); and Type III covering a larger period of appearance March–June but in fewer numbers. The dominant species are discussed, and their food diet is taken into account. 3.- With the Motomura method, that relates the log of their quantity and score, a greater specimen density was found in summer night hauls. However, in the spring daytime hauls, a greater diversity of species and lower density was found. During summer, daytime hauls the density was greater than the diversity. In accordance with hauls at different depth; it seems that an exchange of territory by two species exists: Sebastodes oculatus, a carnivorous fish, dominates the shallow rocky water at night, but in the daytime it goes deeper, giving the space to A. punctatus, an herbivorous (seaweed-feeder) which was living deeper during the night time. A discussion of the possibilities of the species not represented in the samples is included. Finally, temperature and water transparency data were correlated with the abundance of the principal species. The species groups appear more or less a month in advance in relation with the modes of temperature and transparency.