Effect of Fat Body Excision in Female <i>Bufo bufo</i> on the Ipsilateral Ovary, with a Discussion of Fat Body‐Gonad Relationships

Jørgensen, C. Barker

doi:10.1111/j.1463-6395.1986.tb00844.x

Cited by 6 publications

(1 citation statement)

References 28 publications

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“…Similar, or even more drastic, effects have been reported for other anuran species (e.g. Jørgensen 1986). Because fecundity correlates with body size, reduced growth will affect clutch size negatively in the next season.…”

Section: Discussionsupporting

confidence: 85%

Low proportions of reproducing hemiclonal females increase the stability of a sexual parasite–host system (Rana esculenta, R. lessonae)

Reyer

Wälti

Bättig

et al. 2004

Journal of Animal Ecology

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Summary1. The number of reproductive events per lifetime affects all levels of ecological complexity, including the structure and dynamics of species communities. Here we investigate a sexual parasite-host system with two water frog species of which one ( Rana esculenta , E) is a hemiclonal hybrid that depends on one of its parental species ( R. lessonae , L) for successful reproduction. Previous theoretical models have shown that relative fecundities are important for the species composition and stability of this system, but empirical data from natural mixed LE-populations were lacking. 2. We used three different methods to estimate the proportion of annually reproducing hybrid and parental females: (a) screening for eggs through a tiny incision into the belly skin, (b) measuring plasma hormone titres from blood samples and (c) counts of egg clumps deposited into the pond. 3. After accounting for the respective adult population sizes of the two female typescalculated from mark-recapture analyses -we found that all three estimates revealed a higher proportion of reproducing L-than E-females. Ratios ranged from 1·43 (method c), to 1·90 (a) to 2·38 (b), with an average of 1·90. 4. We also investigated three potential causes for the fecundity difference (age structure, hybrid sterility and differences in reproductive costs) but could not find compelling evidence for any of them. We hypothesize that size-related differences in energy budgets offer the most probable explanation. 5. The consequences of the observed species differences in annual reproductive success were analysed with a theoretical model. The higher proportion of reproducing R. lessonae females increases the possibilities for stable coexistence in mixed LE-populations under a variety of combinations of mating patterns, relative fecundity and larval performance. The results, however, also indicate new limits for coexistence and highlight the paramount importance of larval competition for explaining the composition and dynamics of mixed LE-populations.

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Section: Discussionsupporting

confidence: 85%

Low proportions of reproducing hemiclonal females increase the stability of a sexual parasite–host system (Rana esculenta, R. lessonae)

Reyer

Wälti

Bättig

et al. 2004

Journal of Animal Ecology

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Interrelationship between food availability, fat body, and ovarian cycles in the frog,Rana tigrina, with a discussion on the role of fat body in anuran reproduction

Girish

Saidapur

2000

J. Exp. Zool.

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Role of fat bodies in oocyte growth and recruitment in the frog Rana cyanophlyctis (Schn.)

Prasadmurthy

Saidapur

1987

J. Exp. Zool.

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Effects of 30-day bilateral fat body excision in February and November and replacement with 10 or 20 mg fresh aqueous fat body homogenate 6 days a week for 30 days, unilaterally or bilaterally fat body excision plus 20 IU human chorionic gonadotrophin (HCG) in February, and long-term (60 days) fat body excision in March-April were studied in Rana cyanophlyctis. In addition, the effect of ovariectomy on fat body weights in February and November was also studied. The frogs were fed 6 days a week with live guppies ad libitum. The ovarian follicular kinetics was studied by estimating the numbers of first growth phase (FGP), medium and large second growth phase (MSGP and LSGP) oocytes and atretic follicles. Regardless of season, 1-month fat body ablation caused a significant reduction in LSGP oocytes, gonadosomatic index, and increase in atretic follicles. Administration of 20 mg fat body homogenate to fat-body-excised frogs prevented the fall in the number of LSGP oocytes and the gonadosomatic index. In fact, there was a significant increase in the LSGP oocytes and percentage weight of ovaries in these frogs. Follicular atresia was greatly reduced due to fat body homogenate (10 or 20 mg) administration. In 30-day unilaterally fat-body-extirpated frogs, the mean weight of the ipsilateral ovary was reduced to 50% compared to that of the shamoperated frogs due to increased follicular atresia and associated decrease in LSGP oocytes. The administration of HCG increased recruitment of SGP oocytes in unilaterally as well as bilaterally fat-body-ablated frogs. This was accompanied by a reduction in atresia of oocytes and elevation of the gonadosomatic index. Interestingly, in long-term fat-body-ablated frogs, ovarian weight recovered and follicular kinetics in them was identical to that found in shamoperated control frogs. Furthermore, in 30-day ovariectomized frogs, in both seasons there was a significant rise in fat body weights. The above findings in R. cyanophlyctis suggest that fat bodies have a role in vitellogenesis, and they serve as immediate sources of lipid energy needed for follicular growth. If adequate food is provided to fat-body-excised frogs, after an initial setback, ovarian growth commences by drawing lipids from other sources. It is concluded that fat bodies in the frog have a supporting and possibly not an obligatory role in vitellogenic growth of oocytes.

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Effect of Fat Body Excision in Female Bufo bufo on the Ipsilateral Ovary, with a Discussion of Fat Body‐Gonad Relationships

Abstract: Jgrgensen, C. B. 1986. Effect of fat body excision in female Bufo bufo on the ipsilateral. ovary, with a discussion of fat body-gonad relationships. (Zoophysiological Laboratory, August Krogh Institute, Copenhagen, Denmark.)-Acia 2001. (Stockh.) 67, 5-10.

Cited by 6 publications

References 28 publications

Low proportions of reproducing hemiclonal females increase the stability of a sexual parasite–host system (Rana esculenta, R. lessonae)

Low proportions of reproducing hemiclonal females increase the stability of a sexual parasite–host system (Rana esculenta, R. lessonae)

Interrelationship between food availability, fat body, and ovarian cycles in the frog,Rana tigrina, with a discussion on the role of fat body in anuran reproduction

Role of fat bodies in oocyte growth and recruitment in the frog Rana cyanophlyctis (Schn.)

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