ONTOGENIC CHANGES IN FOOD-INTAKE AND DIGESTION RATE OF THE HERBIVOROUS MARINE IGUANA (AMBLYRHYNCHUS-CRISTATUS, BELL)

被引:64
作者
WIKELSKI, M
GALL, B
TRILLMICH, F
机构
[1] BOT INST,ABT SCHEER,W-8000 MUNICH 19,GERMANY
[2] DEPT BEHAV ECOL,W-4800 BIELEFELD 1,GERMANY
关键词
ONTOGENY; HERBIVORY; FOOD INTAKE; DIGESTION; MARINE IGUANA;
D O I
10.1007/BF00317112
中图分类号
Q14 [生态学(生物生态学)];
学科分类号
071012 ; 0713 ;
摘要
Young reptiles have higher relative energy demands than adults, but the proposed ontogenetic changes in diet to fulfil these demands were not found in the algae-eating Galapagos marine iguanas on Santa Fe. Feeding and digestion rates were investigated to analyse how young achieve higher energy intake. Daily food intake of free ranging marine iguana hatchlings (6-11 months old) was about one third that of adults, but relative intake (g dry mass . g-1 wet mass . day-1) was four times higher in the hatchlings. During feeding experiments, relative daily food intake of hatchling marine iguanas was approximately three times higher than that of adults (0.042 vs 0.013 g dry mass . g-0.8 wet mass . day-1), and mean gut passage time was two times shorter (5 vs 1 0 days). The hatchlings also maintained high body temperatures (36.7-degrees-C) even under relatively cool day-time air temperatures of 32-degrees-C. Apparent digestibility of algal food measured both during feeding trials and by Mn2+ AAS (atomic absorption spectrometry) for free-ranging iguanas was 70%, independent of body size and temperature. The red algae prevailing in the diet were high in protein (30% dry mass) and energy (12. 1 kJ/g dry mass). Diving iguanas had higher rates of energy intake than intertidal foragers, but daily intake was less. Maintenance of high body temperature enabled hatchlings to achieve high digestion rates and, combined with high relative intake, thus achieve sufficient energy intake for rapid growth despite higher mass specific metabolic rates. Estimates of biomass of marine iguanas and their algal food are given for a section of coastline on Santa Fe.
引用
收藏
页码:373 / 379
页数:7
相关论文
共 34 条
[1]   OBSERVATIONAL STUDY OF BEHAVIOR - SAMPLING METHODS [J].
ALTMANN, J .
BEHAVIOUR, 1974, 49 (3-4) :227-267
[2]   CELLULOSE DIGESTION AND VOLATILE FATTY-ACID PRODUCTION IN THE GREEN TURTLE, CHELONIA-MYDAS [J].
BJORNDAL, KA .
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-PHYSIOLOGY, 1979, 63 (01) :127-133
[3]  
CARPENTER CHARLES C., 1966, PROC CALIF ACAD SCI, V34, P329
[4]  
DARWIN C, 1883, J RES
[5]  
EIBLEIBESFELD I, 1964, ENCY CINEMATOGRAPHIC
[6]   MICROBIAL DIGESTION IN THE HERBIVOROUS LIZARD UROMASTYX-AEGYPTIUS (AGAMIDAE) [J].
FOLEY, WJ ;
BOUSKILA, A ;
SHKOLNIK, A ;
CHOSHNIAK, I .
JOURNAL OF ZOOLOGY, 1992, 226 :387-398
[7]   EFFECT OF TEMPERATURE ON DIGESTIVE EFFICIENCY IN HERBIVOROUS LIZARD, DIPSOSAURUS-DORSALIS [J].
HARLOW, HJ ;
HILLMAN, SS ;
HOFFMAN, M .
JOURNAL OF COMPARATIVE PHYSIOLOGY, 1976, 111 (01) :1-6
[8]   EFFECT OF TEMPERATURE ON THE DIGESTIVE EFFICIENCY OF 3 SPECIES OF LIZARDS, CNEMIDOPHORUS-TIGRIS, GERRHONOTUS-MULTICARINATUS AND SCELOPORUS-OCCIDENTALIS [J].
HARWOOD, RH .
COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY A-MOLECULAR & INTEGRATIVE PHYSIOLOGY, 1979, 63 (03) :417-433
[9]  
HOBSON E S, 1969, Copeia, P401
[10]  
HOBSON ES, 1965, COPEIA, P249