Skeletal growth rhythmed by seasonal environmental fluctuations in Nile perch (Lates niloticus): implication for paleoclimatic reconstructions - Archive ouverte HAL Accéder directement au contenu
Communication Dans Un Congrès Année : 2022

Skeletal growth rhythmed by seasonal environmental fluctuations in Nile perch (Lates niloticus): implication for paleoclimatic reconstructions

Résumé

Growth in ectotherm vertebrates, especially actinopterygians, is strongly rhythmed by seasonal variation in environmental conditions and by internal physiological controls. Skeletal growth refects the somatic growth rhythm fluctuation by the alternating deposition of different growth marks, observable on thin sections. In tropical regions, growth occurs during the rainy season in many lake and river shes, while it stops during the dry season when resources are not suffcient or when energy is allocated to other functions (e.g., reproduction or healing). The growth rhythm in tropical species would therefore refect the environmental seasonal fluctuations experienced by individuals in their lifetime. Therefore, the study of the growth recorded in fossil bones would allow tracking past seasonal regimes, which would constitute a new way of inferring paleoclimates. However, this approach rst requires to be validated in extant species which are closely related to the studied fossil taxa. For this purpose, we examined the skeletal growth marks of a Nile perch (Lates niloticus) caught in June 2014 in the Chadian Chari River. This species is well represented in African fossil sites since the Miocene. Growth marks were compared within bones and between different bones, and with climatic conditions experienced during life span. Growth occurred at the same rate between the different areas of the same bone and between the different bones (vertebrae, spines, scales). The individual was estimated to be 4-year-old at time of capture. The skeletal growth rate over the past three years was strongly correlated with the environmental seasonal fluctuations, i.e., a small then a large rainy season each year. Consequently, it appears that any fossil record of Nile perch can be used to reconstruct the seasonality that prevailed in the Neogene and Quaternary localities of Africa.
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Dates et versions

hal-03915262 , version 1 (29-12-2022)

Identifiants

  • HAL Id : hal-03915262 , version 1

Citer

Axelle Gardin, Josselin Griffet, Mahamat Adoum, Elise Dufour, Géraldine Garcia, et al.. Skeletal growth rhythmed by seasonal environmental fluctuations in Nile perch (Lates niloticus): implication for paleoclimatic reconstructions. 2nd Virtual Conference for Women Archaeologists and Paleontologists, Mar 2022, online, France. ⟨hal-03915262⟩
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