Studies on Volutids in Argentina (Caenogastropoda, Volutidae)

PENCHASZADEH, P.E., ARRIGHETTI, F., BIGATTI,G., CLEDÓN M., GIMÉNEZ, J., LUZZATTO, D., SANCHEZ ANTELO , C.

Sanibel, Florida, USA

Congreso; American Malacological Society; 2004

Adelomelon brasiliana (Lamarck, 18 1 1) specimens were captured monthly in the Mar rlel Plata area (15m depth) during three consecutive years. The reproductive seasorl extends from September to April. The mature oocytes reach 200 pn in diameter before spawning. In autumn, a resting phase begins, and non-spawned oocytes undergo reabsorption. Among the Volutidae, Adelomelon brasiliana is the only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 diameter before spawning. In autumn, a resting phase begins, and non-spawned oocytes undergo reabsorption. Among the Volutidae, Adelomelon brasiliana is the only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Mar rlel Plata area (15m depth) during three consecutive years. The reproductive seasorl extends from September to April. The mature oocytes reach 200 pn in diameter before spawning. In autumn, a resting phase begins, and non-spawned oocytes undergo reabsorption. Among the Volutidae, Adelomelon brasiliana is the only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 diameter before spawning. In autumn, a resting phase begins, and non-spawned oocytes undergo reabsorption. Among the Volutidae, Adelomelon brasiliana is the only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 only species known to lay free egg capsules. The distribution of egg capsules is aggregated due to bottom currents. Egg capsules are often stranded on the beach afier strong storms; there they die or suffer predation by shore birds. Gonad development of Zidona dufresnei (Donovan, 1823) (Caenogastropoda: Volutidae) was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 was studied over a period of two consecutive years. The reproductive season in this species i11 the sampled locality off Mar del Plata extended from October to March. Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0 Size at first gonadic maturity in females was 12.8 cm shell length and in males 12.0