Nicolas Straube

Nicolas Straube
University Museum of Bergen · Department of Natural History

Dr. rer. nat.

About

73
Publications
56,171
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1,307
Citations

Publications

Publications (73)
Preprint
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The rapid diversification of notothenioid fishes in the waters surrounding the Antarctic continent is a prime example of the process of adaptive radiation. Within around 10 million years, Antarctic notothenioids have diversified into over 100 species with a broad range of lifestyles and ecological adaptations. However, the exact number of species w...
Article
Full-text available
Among vertebrates, sharks exhibit both large and heterogeneous genome sizes ranging from 2.86 to 17.05 pg. Aiming for a better understanding of the patterns and causalities of shark genome size evolution, we applied phylogenetic comparative methods to published genome-size estimates for 71 species representing the main phylogenetic lineages, life-h...
Article
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Background Modern integrative taxonomy-based annelid species descriptions are detailed combining morphological data and, since the last decades, also molecular information. Historic species descriptions are often comparatively brief lacking such detail. Adoptions of species names from western literature in the past led to the assumption of cosmopol...
Data
Otodus megalodon fossil occurrences: blue dots: records after Pimiento et al. (2016); yellow stars and green wale symbol: records after Eastman (1903, 1906), Belyaev & Glikman (1970), Séret (1987); red star: this study; whale symbol: Cetacean ear bones after Eastman (1906) (green together with O. megalodon).
Data
Otodus megalodon fossil occurrences: blue dots: records after Pimiento et al. (2016); yellow stars and green wale symbol: records after Eastman (1903, 1906), Belyaev & Glikman (1970), Séret (1987); red star: this study; whale symbol: Cetacean ear bones after Eastman (1906) (green together with O. megalodon).
Article
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In this short communication, we describe the first reported case of an in-situ observation and subsequent sampling of a fossil Otodus megalodon tooth from a deep-sea locality in the Pacific Ocean (14.11332°N, 167.39357°W; 3090 m depth). The additional documentation of its location prior to collection allows for tentative conclusions on surrounding...
Preprint
Full-text available
Among vertebrates, sharks exhibit both large and heterogeneous genome sizes ranging from 2.86 to 17.05 pg. Aiming for a better understanding of the patterns and causalities of shark genome size evolution, we applied phylogenetic comparative methods to published genome-size estimates for 66 species representing the main phylogenetic lineages, life-h...
Preprint
Full-text available
Although several methods exist for extracting and sequencing historical DNA originating from drypreserved insect specimens deposited in natural history museums, no consensus exists as to what is the optimal approach. We demonstrate that a customized, low-cost archival DNA extraction protocol (∼ €10 per sample), in combination with Ultraconserved El...
Conference Paper
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Moderne Haie werden heute taxonomisch in die zwei Überordnungen Galeomorphii und Squalomorphii eingeteilt. Im Gegensatz zu der sehr diversen Ordnung der Dornhaie (Squaliformes, 143 Arten), enthalten die vier weiteren Ordnungen (Echinorhiniformes, Hexanchiformes, Squatiniformes und Pristiophoriformes) der Squalomorphii insgesamt nur 45 rezente Arten...
Article
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This study describes for the first time a number of distinct fossil teeth documenting several deep-sea shark species from the Eocene, which were previously not recorded from the North Sea Basin, including Apristurus sp., Orthechinorhinus cf. pfeili, Deania cf. angoumeensis, Squaliolus sp., Etmopterus cf. cahuzaci and Paraetmopterus nolfi. Our findi...
Book
Full-text available
The table and provided download links below are intended for informational use in Chondrichthyan research. The allocation aims for faciliating to find species numbers and most recent information on taxonomic changes. We will regularly update the table and download links at lest twice annually. The updates will be announced on facebook (https://www....
Article
Full-text available
In this study, we apply a two-step (untreated and soft tissue stained) diffusible iodinebased contrast-enhanced micro-computed tomography array to a wet-collection Lantern Shark specimen of Etmopterus lucifer. The focus of our scanning approach is the head anatomy. The unstained CT data allow the imaging of mineralized (skeletal) tissue, while resu...
Article
Full-text available
A growing number of publications presenting results from sequencing natural history collection specimens reflect the importance of DNA sequence information from such samples. Ancient DNA extraction and library preparation methods in combination with target gene capture are a way of unlocking archival DNA, including from formalin-fixed wet-collectio...
Article
Full-text available
In the welcome circumstance that species believed extinct are rediscovered, it is often the case that biological knowledge acquired before the presumed extinction is limited. Efforts to address these knowledge gaps, in particular to assess the taxonomic integrity and conservation status of such species, can be hampered by a lack of genetic data and...
Poster
Full-text available
Abstract In this study we conduct literature research of medieval zoological and specifically ichthyological literature which may be the source of motivation for specific ways of mounting dried shark specimens located in several towns in Southern Germany and Austria. German naturalist Conrad Gessner was the first around 1550 ad who described all a...
Article
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Elasmobranchs are characterised by the presence of placoid scales on their skin. These scales, structurally homologous to gnathostome teeth, are thought to have various ecological functions related to drag reduction, predator defense or abrasion reduction. Some scales, particularly those present in the ventral area, are also thought to be functiona...
Article
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The Pacific coast of Colombia is characterized by mangrove ecosystems which play a crucial role as possible nurseries for juvenile sharks. However, trophic food webs from coastal ecosystems are heavily disturbed by increased fishing pressure, which affects numerous shark species. In this region of the Eastern Tropical Pacific (ETP), fisheries’ data...
Article
Full-text available
Due to the peculiar combination of dental features characteristic for different squaliform families, the position of the Late Cretaceous genera Protoxynotus and Paraphorosoides within squaliform families has long been controversial. In this study, we revise these genera based on previously known fossil teeth and new dental material. The phylogeneti...
Article
The Clupeiformes, including among others herrings, anchovies, shads and menhadens are ecologically and commercially important, yet their phylogenetic relationships are still controversial. Previous classification of Clupeiformes were based on morphological characters or lack of synapomorphic characters. More recent studies based on molecular data a...
Article
Full-text available
Etmopteridae (lantern sharks) is the most species-rich family of sharks, comprising more than 50 species. Many species are described from few individuals, and re-collection of specimens is often hindered by the remoteness of their sampling sites. For taxonomic studies, comparative morphological analysis of type specimens housed in natural history c...
Article
Full-text available
A growing number of publications presenting results from sequencing natural history collection specimens reflect the importance of DNA sequence information from such samples. Ancient DNA extraction and library preparation methods in combination with target gene capture are a way of unlocking archival DNA, including from formalin-fixed wet-collectio...
Article
Full-text available
Diet is a crucial trait of an animal’s lifestyle and ecology. The trophic level of an organism indicates its functional position within an ecosystem and holds significance for its ecology and evolution. Here, we demonstrate the use of zinc isotopes (δ66Zn) to geochemically assess the trophic level in diverse extant and extinct sharks, including the...
Article
Full-text available
The newly collected shark and ray tooth fossils from the marine sediments of the Upper Marine Molasse close to Allerding (4.8 km SE of Schärding, Austria) allow for a review of the hitherto known diversity comprising a taxonomic update and the documentation of additional taxa. Besides ten taxa already known from the area, the following taxa were co...
Article
In this study we describe a new kitefin shark (Dalatiidae) genus and species Dracipinna bracheri gen. et sp. nov. based on upper Oligocene and lower Miocene tooth fossils. The teeth were excavated at three different sites which all lie in transgression phases. The fossil shark teeth are diverse and, depending on the excavation site, indicate pelagi...
Article
Sibert and Rubin (Reports, 4 June 2021, p. 1105) claim to have identified a previously unidentified, major extinction event of open-ocean sharks in the early Miocene. We argue that their interpretations are based on an experimental design that does not account for a considerable rise in the sedimentation rate coinciding with the proposed event, nor...
Article
Full-text available
The distinct morphology of teeth of the dogfish sharks Squalus spp. allows for tracking its evolutionary history. Fossils of the genus are known since the early Cretaceous; however, fossilized teeth of Squalus from that period are scarce. Here, we report on the oldest finding of a Squalus tooth fossil (upper Campanian-lower Maastrichtian) from the...
Article
Full-text available
After initial detection of target archival DNA of a 116-year-old syntype specimen of the smooth lantern shark, Etmopterus pusillus , in a single-stranded DNA library, we shotgun-sequenced additional 9 million reads from this same DNA library. Sequencing reads were used for extracting mitochondrial sequence information for analyses of mitochondrial...
Article
Full-text available
Millions of scientific specimens are housed in museum collections, a large part of which are fluid preserved. The use of formaldehyde as fixative and subsequent storage in ethanol is especially common in ichthyology and herpetology. This type of preservation damages DNA and reduces the chance of successful retrieval of genetic data. We applied anci...
Article
Full-text available
A three‐ton shipment of dry shark fins was examined by German customs in 2017 leading to the confiscation of 405 kg of potential CITES species. We analyzed a subsample of this material (115 specimens) using DNA sequence‐based identification and compared results to morphological screening of CITES species. We found a mixture of CITES regulated (4 of...
Article
Full-text available
Apart from wet-collection specimens, shark and ray (Neoselachii) museum collection specimens are often represented as articulated jaws or single teeth. In many cases, detailed information on locality, species identification and data on the specimen's body are lacking. The identification key for jaws and teeth presented herein is part B of a planned...
Article
Full-text available
An important character on several taxonomic levels for shark identification is the tooth morphology. Sharks show a variety of highly specialized dentitions reflecting adaptations to their feeding habits. Intraspecific variation of tooth morphology such as sexual or ontogenetic dimorphism is poorly known in many species, even though tooth morphology...
Article
Full-text available
The subgenus Mantidactylus is a group of frogs endemic to Madagascar, including the largest anuran species on the island. Although these frogs are common and widely distributed, their taxonomy remains unclear. Two species are currently recognised, M. grandidieri and M. guttulatus, with another available name, Rana pigra, considered to be a synonym...
Article
Five Garra species are recognized for the Main Nile basin. Garra vinciguerrae is confirmed as valid species. Three species are new to science, Garra napata sp. nov., G. jamila sp. nov. and G. sannarensis sp. nov. A fourth species, Garra sp. “White Nile”, is known from only a single museum specimen in rather poor condition. Garra napata sp. nov., de...
Article
Full-text available
In addition to articulated, mostly formaldehyde-fixed and ethanol-preserved, taxidermy or anatomical specimens, sharks and rays are represented in scientific collections by numerous jaws and isolated teeth. These specimens often source from historical collections where existing informations about species, sex or geographic origin in many cases are...
Presentation
Full-text available
Deep-sea environment represents a wide proportion of the earth surface. However, it still remains largely mysterious and poorly studied. Up to now, scientists consider that only 1% of the entire biotope was sampled. Deep-sea ecosystems show a lush and extremely diversified fauna, which sometimes presents surprising characteristics such as the abili...
Article
Full-text available
Background Previous molecular studies on the phylogeny and classification of clupeocephalan fishes revealed numerous new taxonomic entities. For re-analysing these taxa, we perform target gene capturing and subsequent next generation sequencing of putative ortholog exons of major clupeocephalan lineages. Sequence information for the RNA bait design...
Article
Fossil tip‐dating allows for the inclusion of morphological data in divergence time estimates based on both extant and extinct taxa. Neoselachii have a cartilaginous skeleton, which is less prone to fossilization compared to skeletons of Osteichthyans. Therefore, the majority of the neoselachian fossil record is comprised of single teeth, which fos...
Poster
Full-text available
Sharks play important roles in maintaining and shaping healthy ecosystems, where some species are even considered keystone species in Chile. The overall abundance of Chilean elasmobranchs has been showing a steady decline. Moreover, little is known about their distribution range, and life history in Patagonia, especially in the Comau fjord in South...
Article
Fossil upper and lower squaliform shark teeth from the upper Austrian marine Molasse (Paratethys, Upper Egerian, Aquitanian) were collected. For testing the phylogenetic signal of 31 reviewed dental characters of both fossil and extant etmopterids and somniosids, we performed phylogenetic analyses using both parsimony and maximum likelihood approac...
Data
This paper contains a collection of 817 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2017. The list is the result of regular queries in numerous journals, books and online publications. It p...
Article
Full-text available
In this study, a diverse fauna of fossil elasmobranch teeth from the Early Miocene (Middle Burdigalian) is analysed. The fossil diversity strongly resembles extant deep-water shark and ray assemblages. The fossils were collected from the Upper Marine Molasse of the lower Ottnangian in the Neuhofener Beds location, Mitterdorf, Germany. The collectio...
Data
This paper contains a collection of 803 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2016. The list is the result of regular queries in numerous journals, books and online publications. It p...
Article
Full-text available
A new species of lanternshark, Etmopterus alphus (Squaliformes: Etmopteridae), is described from the south-western Indian Ocean. The new species resembles other members of the ‘Etmopterus lucifer’ clade in having linear rows of dermal denticles and most closely resembles E. molleri from the south-western Pacific. The new species is fairly common al...
Data
Full-text available
This paper contains a collection of 786 citations (no conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2015. The list is the result of regular queries in numerous journals, books and online publications. It p...
Article
In this study, two parthenogenetic events within a family of the whitespotted bambooshark Chiloscyllium plagiosum are reported. A captive female produced multiple parthenogens. Unexpectedly, a single specimen of a total of nine parthenogens displayed external claspers characterizing the male sex in chondrichthyans. Upon dissection, internal sexual...
Article
Full-text available
Fish scale geckos (Geckolepis) are taxonomically poorly resolved, mainly because of the difficulty of applying standard morphological characters to diagnose taxa. Three species, Geckolepis maculata, G. polylepis, and G. typica, are currently recognized from Madagascar and the Comoro Islands. Molecular studies suggested a number of operational taxon...
Article
Full-text available
Significance The river sharks of the genus Glyphis , widely feared as man-eaters throughout India, remain very poorly known to science. The group constitutes five described species, all of which are considered highly endangered and restricted to freshwater systems in Australasia and Southeast Asia. DNA sequence data derived from 19th-century dried...
Article
Full-text available
Background: Squaliform sharks represent approximately 27 % of extant shark diversity, comprising more than 130 species with a predominantly deep-dwelling lifestyle. Many Squaliform species are highly specialized, including some that are bioluminescent, a character that is reported exclusively from Squaliform sharks within Chondrichthyes. The inter...
Data
Supplementary text: detailed materials and methods for phylogenetic analyses. Supplementary Fig. 1: Plotted results from the MEDUSA analysis with species level representation. Supplementary Table 1: Species richness values (from [15]) for the different shark clades included in the analyses. Supplementary Table 2: Supplementary Table S2. Crown limit...
Article
Full-text available
The vast majority of species within the lanternshark genus Etmopterus harbour complex luminescent markings on their flanks, whose functional significance has long remained obscure. Recent studies, however, suggest these enigmatic photophore aggregations to play a role in intraspecific communication. Using visual modelling based on in vivo luminesce...
Book
Full-text available
This is the second version of the database report “Host-Parasite List” and “Parasite-Host List” of cartilaginous fishes (Chondrichthyes: Elasmobranchii, Holocephali). The two lists result from the analysis of 1,078 research articles reporting on host-parasite relations in diverse species of sharks, rays, and chimaeras. The list contains 6,891 recor...
Data
Full-text available
This paper contains a collection of 1099 citations (685 articles and 414 conference abstracts) on topics related to extant and extinct Chondrichthyes (sharks, rays, and chimaeras) as well as a list of Chondrichthyan species and hosted parasites newly described in 2014. The list is the result of regular queries in numerous journals, books and online...
Article
Full-text available
Counterilluminating animals use ventral photogenic organs (photophores) to mimic the residual downwelling light and cloak their silhouette from upward-looking predators. To cope with variable conditions of pelagic light environments they typically adjust their luminescence intensity. Here, we found evidence that bioluminescent sharks instead emit a...
Article
Full-text available
An annotated checklist of chondrichthyan fishes (sharks, batoids, and chimaeras) occurring in Taiwanese waters is presented. The checklist is the result of a biodiversity workshop held in Mach 2012 as well as on-going systematic revisions by the authors. The chondrichthyan fauna of Taiwan is one of the richest in the world with the number of specie...
Article
Full-text available
n an effort to establish a DNA sequence based checklist of the highly diverse chondrichthyan fauna of Taiwan, we se- quenced the mitochondrial NADH2 gene of 257 freshly sampled specimens of Taiwanese chondrichthyans, which were identified to species level by experts in the field. The newly generated sequences were analysed in the context of an alre...
Article
Full-text available
DNA hybridization capture combined with next generation sequencing can be used to determine the sequences of hundreds of target genes across hundreds of individuals in a single experiment. However, the approach has thus far only been successfully applied to capture targets that are highly similar in sequence to the bait molecules. Here we introduce...
Chapter
Full-text available
AbStrAct. -lantern sharks (Etmopterus spp.) constitute a regular by-catch in longline fisheries conducted along the north-eastern Kerguelen Plateau shelf in depths of 600 to 1700 m. Kerguelen lantern sharks are morphologically close to E. granulosus, E. sp. b, South african E. cf. granulosus, and E. litvinovi. However, molecular phylogenetic analys...
Article
Full-text available
Straube, N., Kriwet, J. & Schliewen, U. K. (2010). Cryptic diversity and species assignment of large lantern sharks of the Etmopterus spinax clade from the Southern Hemisphere (Squaliformes, Etmopteridae). —Zoologica Scripta, 40, 61–75. Many species of the speciose deep-sea shark family Etmopteridae (lantern sharks) are a regular by-catch component...
Article
Full-text available
Deep-sea Lantern Sharks (Etmopteridae) represent the most speciose family within Dogfish Sharks (Squaliformes). We compiled an extensive DNA dataset to estimate the first molecular phylogeny of the family and to provide node age estimates for the origin and diversification for this enigmatic group. Phylogenetic inferences yielded consistent and wel...
Article
Full-text available
Dogfish sharks (Squaliformes) are a highly diverse group of neoselachians occurring in a wide range of marine environments and are common members of deep-sea faunas. The order Squaliformes comprises six families with approximately 98 extant species. The dentition of most squaliforms is characterized by a strong dignathic heterodonty and dental vari...