scholarly journals Diversity of compounds in femoral secretions of Galápagos iguanas (genera:AmblyrhynchusandConolophus), and their potential role in sexual communication in lek-mating marine iguanas (Amblyrhynchus cristatus)

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3689 ◽  
Author(s):  
Alejandro Ibáñez ◽  
Markus Menke ◽  
Galo Quezada ◽  
Gustavo Jiménez-Uzcátegui ◽  
Stefan Schulz ◽  
...  
Keyword(s):  
Potential Role ◽  
Sexual Communication ◽  
Eicosenoic Acid ◽  
Lipophilic Compounds ◽  
Femoral Glands ◽  
Lek Mating ◽  
Amblyrhynchus Cristatus ◽  
Marine Iguanas ◽  
Marine Iguana ◽  
Femoral Secretions

BackgroundChemical signals are widely used in the animal kingdom, enabling communication in various social contexts, including mate selection and the establishment of dominance. Femoral glands, which produce and release waxy secretions into the environment, are organs of central importance in lizard chemical communication. The Galápagos marine iguana (Amblyrhynchus cristatus) is a squamate reptile with a lek-mating system. Although the lekking behaviour of marine iguanas has been well-studied, their potential for sexual communication via chemical cues has not yet been investigated. Here we describe the diversity of the lipophilic fraction of males’ femoral gland secretions among 11 island populations of marine iguanas, and compare it with the composition of its sister species, the Galápagos land iguana (Conolophus subcristatus). We also conducted behavioural observations in marine iguana territorial males in order to explore the possible function of these substances in the context of male dominance in leks.MethodsFemoral secretions were analysed by gas chromatography coupled to mass spectrometry (GC–MS), and chromatography with a flame ionisation detector (GC-FID) in order to characterise the lipophilic composition. To understand the potential role of femoral secretions in marine iguana intraspecific communication, territorial males were sampled for their femoral glands and monitored to record their head bob rate—a territorial display behaviour in males—as well as the number of females present in their leks.ResultsWe found that the gland secretions were composed of ten saturated and unsaturated carboxylic acids ranging in chain length between C16and C24, as well as three sterols. Cholesterol was the main compound found. Intriguingly, land iguanas have a higher diversity of lipophilic compounds, with structural group of lipids (i.e. aldehydes) entirely absent in marine iguanas; overall the chemical signals of both species were strongly differentiated. Lipid profiles also differed among populations of marine iguanas from different islands, with some islands demonstrating a high diversity of lipophilic compounds (i.e. full spectra of compounds), and others lacking one or more compounds. Among the compounds most frequently found missing were 11- and 13-eicosenoic acids. Gland secretions of males with a better body condition and with a higher dominance status (i.e. those accompanied by females and with higher head bob display) were proportionately richer in C20-unsaturated fatty acids (11-eicosenoic acid).DiscussionLand and marine iguanas strongly diverged in their chemical composition of the femoral glands likely due to ecological differences between both species. Despite that marine iguana populations varied in their femoral gland composition that was not related to their genetic structure. Our results indicated that 11-eicosenoic acid may play an important role in intraspecific chemical communication in marine iguanas.

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.

New highly polymorphic microsatellite loci for the Galápagos marine iguana, Amblyrhynchus cristatus

2012 ◽  
Vol 33 (3-4) ◽  
pp. 533-536 ◽  
Author(s):  
Amy MacLeod ◽  
Volker Koch ◽  
Carolina García-Parra ◽  
Fritz Trillmich ◽  
Sebastian Steinfartz
Keyword(s):  
Microsatellite Loci ◽  
Galapagos Archipelago ◽  
Amblyrhynchus Cristatus ◽  
Dinucleotide Motif ◽  
Hardy Weinberg Equilibrium ◽  
Marine Iguanas ◽  
Successful Amplification ◽  
Marine Iguana ◽  
Unique Species ◽  
Significant Linkage

We describe the development and characterisation of six new dinucleotide motif microsatellite loci for populations of marine iguanas (Amblyrhynchus cristatus), endemic to the Galápagos archipelago. Primers were based on microsatellite-bearing sequences and initially developed using universally labelled primers. When analysed across 5 populations (representing 150 individuals), new loci displayed, on average, high levels of genetic diversity (range: 2-13 alleles, mean: 5.73) and values of heterozygosity (range: 0.0-0.906, mean: 0.605). No consistent deviations from Hardy-Weinberg equilibrium or significant linkage disequilibrium were observed, and all loci were shown to be free of common microsatellite errors. Utilising the 13 previously available microsatellite loci for this species, we describe here four multiplex combinations for the successful amplification of 19 microsatellite loci for marine iguanas. This powerful set of highly polymorphic markers will allow researchers to explore future questions regarding the ecology, evolution, and conservation of this unique species.

Trophic niche differentiation mirrors intra-island population structure of Galápagos marine iguanas (Amblyrhynchus cristatus)

2019 ◽  
Author(s):  
Sten Anslan ◽  
Timm Reinhardt ◽  
Patrick Fink ◽  
Mario Brauns ◽  
Nicolás Peñafiel ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Genetic Differentiation ◽  
Stable Isotope Analysis ◽  
Isotope Analysis ◽  
Trophic Niche ◽  
Ecological Niches ◽  
Amblyrhynchus Cristatus ◽  
Significant Difference ◽  
Marine Iguanas ◽  
Marine Iguana

Abstract Background: Differences in the trophic niche often underlie ecological specialization of individuals and can promote ecological speciation of populations, but studies showing a link between differences in the trophic niche and genetic differentiation of populations are rare. On the island of San Cristóbal (Galapágos archipelago), a strong genetic differentiation between two relatively proximate populations (subspecies; Amblyrhynchus cristatus mertensi and A. c. godzilla) of marine iguanas along the coastline has been observed. Here, we explore whether this genetic differentiation is mirrored in the iguanas’ trophic niche. Results: Although, no significant difference in the number of consumed algal taxa between subspecies were detected, the Schoener index exhibited low diet overlap between A. c. mertensi and A. c. godzilla. The latter was also demonstrated by the PERMANOVA analysis with significantly different diet OTU composition from the fecal samples between subspecies. Stable isotope analysis revealed that subspecies identity was overall more important than site for the iguanas’ resource use. Conclusions: By applying a metabarcoding approach on feces samples in combination with stable isotope analysis of skin sheds, we found that A. c. mertensi and A. c. godzilla differ in their ecological niches. Moreover, stable isotope analysis indicated that marine iguana populations have low spatial foraging distances, which, together with the diet partitioning patterns, might explain, at least partially, the lack of gene flow between these geographically proximate marine iguana populations. Key words: diet analysis, trophic niche, metabarcoding, stable isotopes, marine iguanas, Amblyrhynchus cristatus

Swimming, Diving and Lactate Production of the Marine Iguana, Amblyrhynchus cristatus

Copeia ◽  
1976 ◽  
Vol 1976 (4) ◽  
pp. 709 ◽  
Author(s):  
George A. Bartholomew ◽  
Albert F. Bennett ◽  
William R. Dawson
Keyword(s):  
Lactate Production ◽  
Amblyrhynchus Cristatus ◽  
Marine Iguana

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.

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