Alguns aspectos da biologia de Subulina octona (Bruguiere,1789) (Gastropoda, Pulmonata, Subulinidae) em condi??es de laborat?rio

Autor: Bessa, Elisabeth Cristina de Almeida
Přispěvatelé: Ara?jo, Jos? Luiz de Barros, Amato, Suzana Bncke, Jurberg, Pedro
Jazyk: portugalština
Rok vydání: 1990
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UFRRJ
Universidade Federal Rural do Rio de Janeiro (UFRRJ)
instacron:UFRRJ
Popis: Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2020-09-18T14:03:09Z No. of bitstreams: 1 1990- Elisabeth Cristina de Almeida Bessa.pdf: 506126 bytes, checksum: df210253a0732e334282cb6065b82b28 (MD5) Made available in DSpace on 2020-09-18T14:03:09Z (GMT). No. of bitstreams: 1 1990- Elisabeth Cristina de Almeida Bessa.pdf: 506126 bytes, checksum: df210253a0732e334282cb6065b82b28 (MD5) Previous issue date: 1990-12-27 Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq In order to understand the biology Subulina octona (Brugui?re, 1789) under laboratory conditions the following reproductive and developmental characteristics have been studied: oviposition; size of the eggs; period of incubation; occurence of self-fertilization; growth of the shell; and the development of specimens fed with different diets (lettuce; lettuce plus concentrated ration). The study 42 individually isolated specimens of S. octona during 182 days indicated that oviposition occur between 10 pm and 10 am with maximum peak between 10 pm and 4 am. The number of oviposition per snail varied from 11 to 19 with two to eight eggs per cluster and a total of 42 to 112 eggs were layed by a singles snails during the period of study. The interval between ovipositions was from seven to 31 days with 76% of the cases concentrated between seven to 15 days. Measurements of 180 eggs showed that the value for the greatest axis varied from 1.5 to 2.0 mm (1.6 mm, was the most frequent) while that of smallest axis varied from 1.2 to 1.6 mm (1.3 mm was the most frequent). The period of incubation of 137 eggs (layed in February 1990) varied from one to 14 days. Self-fertilization in S. octona was observed among 32 snails, individualy isolated for 154 days; eggs were detected in 38 to 50-days-old sanils; total number of ovipositions varied from six-nine; number of eggs per cluster, one-nine; total number of eggs per snail, 16-56. A period of incubation of one to 15 days and a viability of 94.8% were observed for eggs layed in July of 1990 by these isolated snails. Thirty-two specimens were measured to determine length of shell of recently ecloted snails and growth rates. The lenght of shell of recently ecloded snails was 1.3-1.8 mm. Growth rates were established after detection of the first egg-bearing specimen, with 15 days interval measurements; during the first 45 days shells grew 0.8 to 1.5 mm and during the last 75 days, 0.2-1.0 mm. Snails fed for 30 days with lettuce achieved less than half of the lenght of snails fed with lettuce plus concentrated ration. Objetivando conhecer aspectos da biologia de Subulina octona (Brugui?re, 1789) em condi??es de laborat?rio, foram estudadas as seguintes caracter?sticas reprodutivas e de desenvolvimento: oviposi??o, tamanho de ovos, per?odo de incuba??o, ocorr?ncia de autofecunda??o, crescimento da concha e desenvolvimento de exemplares alimentados com alface e com alface e ra??o concentrada. A partir de 42 exemplares de S. octona isolados, um a um, por 182 dias, verificou-se que as posturas s?o realizadas entre 22:00 e 10:00 horas com o pico m?ximo entre 22:00 e 4:00 horas. O n?mero de posturas por moluscos variou de 11 a 19, o n?mero total de ovos por postura de dois a oito e o de ovos por molusco de 42 a 112. O intervalo entre as posturas variou de sete a 31 dias, com 76% dos intervalos concentrados entre sete e 15 dias. Medidas de 180 ovos mostraram que os valores para eixo maior variaram de 1,5 a 2,0 mm (valor modal=1,6 mm) e para eixo menor de 1,2 a 1,6 mm (valor modal = 1,3 mm). A partir de 137 ovos postos em fevereiro/1990, verificou-se que o per?odo de incuba??o foi de um a 14 dias. Confirmou-se a ocorr?ncia de autofecunda??o em S. octona a partir de 32 jovens rec?m-eclodidos, isolados um a um por 154 dias. Constatou-se a presen?a de ovos nos exemplares isolados, 38 a 50 dias ap?s eclos?o. Verificou-se ainda que o n?mero de posturas foi de seis a nove, o n?mero total de ovos por posturas de um a nove e o de ovos por molusco de 16 a 56; a partir de ovos postos em julho/1990 obteve-se 94,8% de viabilidade, sendo o per?odo de incuba??o de um a 15 dias. Em 32 exemplares rec?m-eclodidos constatou-se medidas de concha de 1,3 a 1,8 mm. A partir do aparecimento do primeiro exemplar com ovo foram realizadas medidas quinzenais de todos os exemplares, verificando-se que nos primeiros 45 dias ap?s este evento, as conchas cresceram de 0,8 a 1,5 mm e que nos ?ltimos 75 dias os valores estiveram entre 0,2 e 1,0 mm. Os moluscos alimentados durante 30 dias com alface alcan?aram menos da metade do comprimento daqueles alimentados com alface e ra??o concentrada.
Databáze: OpenAIRE
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