Crepidula cachimilla (Mollusca: Gastropoda), a new species from Patagonia, Argentina

A new species, Crepidula cachimilla, is described based on a population from 15 m depth in San Antonio Oeste, Argentina. Shell length ranged from 5.4 to 28.5 mm for males and from 9.6 to 52.2 mm for females. The minimum shell length recorded for a brooding female was 23.5 mm, and the maximum shell length was 49.3 mm. A detailed anatomical description is given, showing as main characters of the species a relative thick columellar muscle, a greater closure of the palliai cavity aperture by a fusion of the mantle border, a very small osphradium, with about 16 broad filaments, endostyle divided by a middle longitudinal furrow, very large salivary glands, duplication of both gastric ducts to the digestive gland, male seminal vesicle very long and with irregular walls, pallial oviduct with a broad vaginal duct and a tall papilla originating both from palliai floor and roof. Brood egg masses of mature females contained from 15 to 65 egg capsules. The triangular-shaped egg capsules measured between 2.2 and 3.4 mm in length and between 2.3 and 3.8 mm in width. Each egg capsule contained between 129 and 563 eggs. The number of eggs per capsule and the egg diameter did not correlate with female shell length. Uncleaved eggs measured between 180 and 200 μm in diameter. They all developed synchronously within the egg capsules. Prehatching veliger shells measured between 260 and 300 μm in length. After hatching at the veliger stage, protoconch length during metamorphosis ranged between 700 and 800 μm. These parameters neither coincide with those reported by Hoagland (1977) for the similar Californian Crepidula onyx, nor with the reproductive characters reported by Miloslavich & Penchaszadeh (2001) for Crepidula aplysioides, which supposedly occurs in the region.Fil:Cledón, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Penchaszadeh, P.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Crepidula cachimilla (Mollusca: Gastropoda), a new species from Patagonia, Argentina

A new species, Crepidula cachimilla, is described based on a population from 15 m depth in San Antonio Oeste, Argentina. Shell length ranged from 5.4 to 28.5 mm for males and from 9.6 to 52.2 mm for females. The minimum shell length recorded for a brooding female was 23.5 mm, and the maximum shell length was 49.3 mm. A detailed anatomical description is given, showing as main characters of the species a relative thick columellar muscle, a greater closure of the palliai cavity aperture by a fusion of the mantle border, a very small osphradium, with about 16 broad filaments, endostyle divided by a middle longitudinal furrow, very large salivary glands, duplication of both gastric ducts to the digestive gland, male seminal vesicle very long and with irregular walls, pallial oviduct with a broad vaginal duct and a tall papilla originating both from palliai floor and roof. Brood egg masses of mature females contained from 15 to 65 egg capsules. The triangular-shaped egg capsules measured between 2.2 and 3.4 mm in length and between 2.3 and 3.8 mm in width. Each egg capsule contained between 129 and 563 eggs. The number of eggs per capsule and the egg diameter did not correlate with female shell length. Uncleaved eggs measured between 180 and 200 μm in diameter. They all developed synchronously within the egg capsules. Prehatching veliger shells measured between 260 and 300 μm in length. After hatching at the veliger stage, protoconch length during metamorphosis ranged between 700 and 800 μm. These parameters neither coincide with those reported by Hoagland (1977) for the similar Californian Crepidula onyx, nor with the reproductive characters reported by Miloslavich & Penchaszadeh (2001) for Crepidula aplysioides, which supposedly occurs in the region.Fil:Cledón, M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Penchaszadeh, P.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina