The energetic costs of tail autotomy to reproduction in the lizard Coleonyx brevis (Sauria: Gekkonidae)

Abstract

Energy reserve utilization and energy budgets were compared in tailed and tailless adult female Coleonyx brevis. Carcass, fat body and caudal energy reserves were used for vitellogenesis; mass and energy content (cal/mg and/or cal/reserve) of each were significantly lower at oviposition than at the initiation of vitellogenesis. Total energy reserves accounted for 53% of the reproductive energy investment in tailed females compared to 29% in tailless females. Tailed females had over twice as many reserve calories for egg production than tailless females. Caudal energy reserves represented 60% of the total reserves of tailed females and were one-third greater than the total energy reserves of tailless females. To produce a clutch of eggs both tailed and tailless females supplemented energy reserves with net metabolizable energy that was available after metabolic costs were paid. Tailless females had a significantly greater rate of food ingestion and more net metabolizable energy available for reproduction than tailed females, yet allocated significantly fewer calories/day to reproduction than tailed females, primarily because of the loss of caudal reserves. Reproductive efforts of tailed and tailless females were equivalent. However, the loss of caudal reserves resulted in the production of eggs that were significantly lower in mass and energy content (cal/mg and cal/egg) than when caudal reserves were used. Results empirically support the hypothesis that reproduction has energetic priority over tail regeneration in short-lived, iteroparous species with a low probability of future reproductive success.

Reduced tail regeneration in the Common Lizard, Lacerta vivipara, parasitized by blood parasites

“…Depending on what is more beneficial to an individual's fitness, one of these investments may have priority over the other. Maiorana (1977) demonstrated in one species of salamander that tail regeneration has energetic priority over reproduction, but in a lizard species Coleonyx brevis, Dial & Fitzpatrick (1981) showed that tailless females prioritize energy allocation to reproduction at the expense of tail regeneration. This is also the case in the Common Lizard where pregnant females significantly reduce tail regeneration during gestation when compared with adult males (P < 0·05; M. Massot & J. Clobert, unpublished data).…”

Leg regeneration stunts wing growth and hinders flight performance in a stick insect ( Sipyloidea sipylus )

“…Since appendage regeneration requires the allocation of resources, this process can have profound consequences. In some lizards, for example, regeneration of a lost tail significantly reduced fecundity (Smyth 1974;Maiorana 1977;Dial & Fitzpatrick 1981;Norman & Jones 1993). However, tradeoffs between somatic and reproductive growth are not the only types of allocation tradeoffs that can affect fitness.…”

The impact of limb autotomy on mate competition in blue crabs Callinectes sapidus Rathbun

“…Studies of lizard, salamander, and insect populations have shown that autotomy frequency is often density-dependent (Robinson et al 1991a;Van Buskirk and Smith 1991) and that injury can lower individual fecundity and delay breeding (Smyth 1974;Maiorana 1977;Dial and Fitzpatrick 1981). The present study is significant in showing that autotomy has the potential to affect male-male competition in a polygynous mating system.…”

“…Appendage loss might decrease an individual's ability to attract mates, lower competitive performance for partners, physically hinder copulation, or reduce fecundity. Of these potential costs, only the effect of autotomy on fecundity has been examined in any detail (e.g., Dial and Fitzpatrick 1981). Studies of salamanders and lizards indicate decreased reproductive effort following autotomy because either energetic reserves are lost or metabolic resources are diverted from egg production to regeneration (Smyth 1974;Maiorana 1977;Vitt et al 1977;Dial and Fitzpatrick 1981;Vitt and Cooper 1986).…”

“…Of these potential costs, only the effect of autotomy on fecundity has been examined in any detail (e.g., Dial and Fitzpatrick 1981). Studies of salamanders and lizards indicate decreased reproductive effort following autotomy because either energetic reserves are lost or metabolic resources are diverted from egg production to regeneration (Smyth 1974;Maiorana 1977;Vitt et al 1977;Dial and Fitzpatrick 1981;Vitt and Cooper 1986). The impact of autotomy on mate choice, mate competition (Sekkelsten 1988), or the mechanics of pairing has received surprisingly little attention.…”