Population Biology of Marine Iguanas (Amblyrhynchus cristatus). III. Factors Affecting Survival

10.2307/4880 ◽  
1990 ◽  
Vol 59 (2) ◽  
pp. 545 ◽  
Author(s):  
W. A. Laurie ◽  
D. Brown
Keyword(s):  
Population Biology ◽  
Factors Affecting ◽  
Amblyrhynchus Cristatus ◽  
Marine Iguanas

DNA metabarcoding reveals fine scale geographical differences of consumed algae in the Galápagos marine iguanas (Amblyrhynchus cristatus)

2021 ◽  
pp. 1-10
Author(s):  
Sten Anslan ◽  
Denisse Dalgo ◽  
Timm Reinhardt ◽  
Nicolás Peñafiel ◽  
Juan Guayasamin ◽  
...  
Keyword(s):  
Algal Species ◽  
Marine Macroalgae ◽  
Rbcl Gene ◽  
Ribulose Bisphosphate Carboxylase ◽  
Geographical Differences ◽  
Bisphosphate Carboxylase ◽  
Amblyrhynchus Cristatus ◽  
Dna Metabarcoding ◽  
Feeding Activities ◽  
Marine Iguanas

Abstract Galápagos marine iguanas are primarily associated with the marine environment and show special nutritional adaptations. They are the only lizards worldwide that forage on marine macroalgae. Until now, consumed algae have been identified by direct observations during their feeding activities and microscopic identification in faeces samples. In this study, we use a novel DNA metabarcoding approach to identify consumed algal species from the faeces of marine iguanas. We developed primers for the ribulose-bisphosphate carboxylase (rbcL) gene and applied a metabarcoding approach to 25 individual faeces samples collected in four representative sites of two subspecies (Amblyrhynchus cristatus mertensi and A. c. godzilla), found in the San Cristóbal Island. We detected 18 consistently occurring macroalgal operational taxonomic units (OTUs). Most of the OTUs were assigned to Rhodophyta (red algae) and only one OTU to Chlorophyta (green algae). Despite the number of consumed algal species did not differ between two subspecies (OTU richness; P = 0.383), diet overlap level between A. c. mertensi and A. c. godzilla was low (Schoener index = 0.345), suggesting that both subspecies consumed different algal species in their natural environment. Further studies are needed to understand whether the difference of consumed algae reflects disparities in the abundance of algal species between sites, or whether iguanas of the two genetically differentiated subspecies prefer distinct algal species.

Factors affecting resistance to insecticides in house-flies, Musca domestica L. (Diptera: Muscidae). IV. The population biology of flies on animal farms in south-eastern England and its implications for the management of resistance

1985 ◽  
Vol 75 (1) ◽  
pp. 143-158 ◽  
Author(s):  
I. Denholm ◽  
R. M. Sawicki ◽  
A. W. Farnham
Keyword(s):  
Gene Flow ◽  
Musca Domestica ◽  
Population Biology ◽  
Marker Gene ◽  
House Fly ◽  
Factors Affecting ◽  
House Flies ◽  
Resistance Selection ◽  
South Eastern ◽  
Brown Body

AbstractWays in which the bionomics and dynamics of populations of Musca domestica L. can influence the development of insecticide resistance, and how resistance genes spread within and between farms was investigated in a three-year study of the biology and movement of flies on 63 pig-rearing farms in south-eastern England. House-flies survived winter only on 12 ‘overwintering’ farms where they bred in heated pig-rearing houses (‘closed buildings’) throughout the year. In late spring they appeared out doors, and their descendents founded populations on neighbouring ‘summer’ farms where pigs breed only in unheated (‘open’) buildings. There, flies reached peak numbers in August–September and died out by mid-November. Gene flow within and between farms was studied indirectly by mark-release-recapture of colour-marked adults, and directly by monitoring the diffusion of the visible marker gene bwb (brown body) introduced into indigenous house-fly populations. Although movement between open buildings within a farm was unrestricted, dispersal between farms was limited, and gene flow between even adjacent closed buildings was indirect, and required more than one generation. Likewise, indirect and gradual gene flow during summer probably accounted for the similarity in type and frequency of other independent genetic markers of local overwintering populations. Thus closed buildings played a key role in house-fly ecology and population genetics. Unfortunately, control with persistent insecticides in these buildings ensures efficient resistance selection, ultimately resulting in its spread to all pig farms. Less selective control practices are needed at these sites.

The fighting behaviour of marine iguanas

1966 ◽  
Vol 251 (772) ◽  
pp. 475-476 ◽  
Keyword(s):  
Maternal Behaviour ◽  
Bond Forming ◽  
Amblyrhynchus Cristatus ◽  
The Social ◽  
Marine Iguanas ◽  
Marine Iguana ◽  
Bodily Contact ◽  
Forming Behaviour ◽  
Fighting Behaviour ◽  
Striking Contrast

The Marine Iguana ( Amblyrhynchus cristatus ) is a species endemic to the Galapagos Islands. It lives in large aggregations along the rocky shore lines throughout the archipelago. It is the only iguanid specialized for feeding on marine algae, which they crop at low tide from the exposed rocks or even by diving down to the bottom of the sea. The animals are extremely gregarious and sometimes hundreds of iguanas bask on the lava rocks in bodily contact with each other. Besides this mutual attraction, however, no specific forms of social interaction like grooming, mutual feeding rituals, etc. are to be observed. This is in striking contrast to the social behaviour of birds and mammals which use such patterns for bond formation. These bond-forming behaviour patterns are mainly derivates of maternal behaviour, which seem to be preadapted for this purpose. Reptiles lack maternal behaviour and this may in part explain their inability to form a closer bond between adults.

scholarly journals Progressive colonization and restricted gene flow shape island-dependent population structure in Galápagos marine iguanas (Amblyrhynchus cristatus)

2009 ◽  
Vol 9 (1) ◽  
pp. 297 ◽  
Author(s):  
Sebastian Steinfartz ◽  
Scott Glaberman ◽  
Deborah Lanterbecq ◽  
Michael A Russello ◽  
Sabrina Rosa ◽  
...  
Keyword(s):  
Population Structure ◽  
Gene Flow ◽  
Restricted Gene Flow ◽  
Amblyrhynchus Cristatus ◽  
Marine Iguanas
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