ALEXANDROS FRANTZIS results 12
· Newest (Page 1/1, per page 25)
Author: ALEXANDROS FRANTZIS ×Clear All Filters
Search Results
Corrigendum to “KOUTOUZI, N., ALEXIADOU, P., POLYCHRONIDIS, L., FRANTZIS, A., FOSKOLOS, I., 2026. Stomach contents of three deep-diving toothed whale species stranded in Greece, eastern Mediterranean. Mediterranean Marine Science, 27 (1), 71–82. https://doi.org/10.12681/mms.42351”
Understanding trophic ecology is essential for assessing the role of top predators in marine food webs. In the Mediterranean Sea, toothed whales are key components of megafauna and for this reason, we investigated the diets of nine deep-diving odontocetes stranded along the Greek coastline: five Risso’s dolphins (Grampus griseus), three goose-beaked whales (Ziphius cavirostris) and one sperm whale (Physeter macrocephalus). A t...
Genomics reveals the role of admixture in the evolution of structure among sperm whale populations within the Mediterranean SeaNARA Subscribed
In oceanic ecosystems, the nature of barriers to gene flow and the processes by which populations may become isolated are different from the terrestrial environment, and less well understood. In this study we investigate a highly mobile species (the sperm whale, Physeter macrocephalus ) that is genetically differentiated between an open North Atlantic population and the populations in the Mediterranean Sea. We apply high‐resol...
Estimating body mass of sperm whales from aerial photographsNARA Subscribed
Body mass is a fundamental feature of animal physiology. Although sperm whales ( Physeter macrocephalus ) are the largest toothed predators on earth, body mass is seldom included in studies of their ecophysiology and bioenergetics due to the inherent difficulties of obtaining direct measurements. We used UAV‐photogrammetry to estimate the weight of free‐ranging sperm whales. Aerial photographs (23 calves, 11 juveniles, 55 nonm...
A Real-Time Acoustic Observatory for Sperm-Whale Localization in the Eastern Mediterranean SeaOA Marine
A deep-water acoustic observatory for real-time detection and localization of vocalizing sperm whales was developed, deployed and operated for two 3-month periods in summer 2020 and 2021, off south-west Crete in the Eastern Mediterranean Sea, in the framework of the SAvEWhales project. Regular clicks, pulsed sounds produced by the diving animals, were detected and localized using a large-aperture array of three hydrophones sus...
The sperm whale (Physeter macrocephalus) is the largest odontocete occurring in the Greek Seas. However, monitoring thespecies’ spatiotemporal distribution patterns is especially difficult during the winter months when unfavorable weather conditionsoften hinder survey efforts. In the Greek Seas, visual cetacean surveys are typically not conducted between November and March. In a first attempt to collect year-round baseline inf...
The mechanisms that determine population structure in highly mobile marine species are poorly understood, but useful towards understanding the evolution of diversity, and essential for effective conservation and management. In this study, we compare putative sperm whale populations located in the Gulf of Mexico, western North Atlantic, Mediterranean Sea and North Sea using mtDNA control region sequence data and 16 polymorphic...
Worldwide structure of mtDNA diversity among Cuvier's beaked whales ( Ziphius cavirostris ): implications for threatened populationsNARA Subscribed
We present the first description of phylogeographic structure among Cuvier's beaked whales ( Ziphius cavirostris ) worldwide using mitochondrial DNA (mtDNA) control region sequences obtained from strandings ( n = 70), incidental fisheries takes ( n = 11), biopsy ( n = 1), and whale‐meat markets ( n = 5). Over a 290‐base pair fragment, 23 variable sites defined 33 unique haplotypes among the total of 87 samples. Nucleotide dive...
Previous1Next