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University of Namibia (2018)

A description of reproduction, diet, nematode infection and sexualdimorphism in Agama anchietae and Pedioplains indata undata (Reptilia : Lacertilia) in Namibia

Buiswalelo, Bertha N.

Titre : A description of reproduction, diet, nematode infection and sexualdimorphism in Agama anchietae and Pedioplains indata undata (Reptilia : Lacertilia) in Namibia

Auteur : Buiswalelo, Bertha N.

Université de soutenance  : University of Namibia

Grade : Master of Science in Biodiversity Management 2018

Résumé
The objectives of this study were to describe reproduction, diet, nematode infection and sexual dimorphism in Agama anchietae and Pedioplanis undata undata, two Namibian lizard species with wide geographic distributions for which such baseline ecological information is still lacking. The specimens used in the study came from the preserved Herpetological Collection of the National Museum of Namibia. Agama anchietae occupies rocky areas and the findings were as follows, reproduction : (i) it reproduces in spring and summer, the warm and rainy season of Namibia when insect food abounds, presumably to optimize the survival of its offspring, (ii) the gonads were inactive during autumn and winter, (iii) the mass of its abdominal fat bodies and liver decreased during the reproductive period, presumably because they serve as sources of energy during that time ; diet : (i) prey items consumed by the sexes belonged to the orders Hymenoptera, Coleoptera, Lepidoptera and Mantodea, (ii) in addition to these an item belonging to the Diptera was also found in males, (iii) no significant numerical differences were found between the sexes with respect to the items consumed, (iv) the fact that hymenopterans occurred in substantially higher numbers suggest that the species relies mainly on sit-and-wait foraging ; nematode infection : (i) in both sexes a larger number of nematodes occurred in the stomach than in the intestine, (ii) no significant numerical differences in infection were found between the sexes ; sexual dimorphism : (i) males were larger than females in absolute body size, (ii) relative hind-limb but not forelimb length of males was significantly longer than that of females ; (iii) relative head breath, length and width of males were all significantly greater than that of females. Pedioplanis undata undata occurs in flat open areas and the findings were as follows, reproduction : (i) a similar pattern with respect to the activity of the gonads as reported for A. anchietae above was also found in this species, (ii) the same also applied to the mass fluctuations of the abdominal fat bodies and the liver ; diet : (i) males consumed items belonging to the orders Hymenoptera, Isoptera, Coleoptera, Lepidoptera, Blatoidea, Solifugida as well as larvae, (ii) in females the prey items belonged to the Hymenoptera, Orthoptera, Coleoptera, Hemiptera and Aranea, (iii) no significant numerical differences were found between the sexes for similar prey items, (iv) the low numbers of hymenopterans but fairly high diversity of prey types suggest that this species is a wide forager ; nematode infection : (i) in both the stomach and intestine nematode infection was low with that of the stomach marginally higher than that of the intestine, (ii) no significant numerical differences were found between males and females ; sexual dimorphism : (i) males and females were of similar body size, (ii) males had significantly longer fore-and hind-lim

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Page publiée le 22 novembre 2018