Elasmobranchs Research Papers - Academia.edu (original) (raw)

Ocean acidification and warming have the potential to profoundly impact marine fishes by reducing embryo fitness and survival. Local adaptation to thermal gradients may reduce the impact of global warming, but whether fish from different populations may respond differently to climatic stressors remains unknown. The hypothesis that acidification and warming may have an effect on development, aerobic scope, and survival was tested in little skate (Leucoraja erinacea) embryos from two latitudinally separated populations. Temperature had the strongest effect on development, survival and metabolic rates, but acidification further exacerbated stress on embryos from the Gulf of Maine population by increasing the costs of activity, development time, and reducing body condition of newly hatched skates. Active metabolic rates of both populations exhibited countergradient variation with peak of performance at 18°C, but were affected differently by acidification. These findings demonstrate that even adjacent fish populations may respond differently to increasing temperature and acidification and emphasize the need for multi-stressor studies on different populations of fishes with wide geographic range to understand complex responses to climate change and other environmental challenges.

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- Climate Change, Conservation Biology, Fish Physiology, Elasmobranchs

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 collected for the first time from the site:

- by Jürgen Pollerspöck and +1
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- Fossil Fish, Sharks, Elasmobranchs, Miocene

RESUMO O registro de processos reprodutivos de elasmobrânquios são raros e pouco documentados em aquários destinados à visitação pública. O presente trabalho registra o primeiro caso de distocia em raia-ticonha (Rhinoptera bonasus), (Mitchill, 1815). O exemplar, mantido em cativeiro por 16 anos, apresentou uma gestação de 14 meses. Não houve ocorrência do parto natural, sendo necessária a intervenção humana através de manobras obstétricas para a retirada do feto. Os procedimentos descritos podem ser utilizados como referência em outros casos de distocia com esta espécie. ABSTRACT The registration of reproductive processes of elasmobranchs is rare and little documented in public aquariums. The present work registers the first case of dystocia in cownose ray (Rhinoptera bonasus), (Mitchill, 1815). The ray maintained in captivity by 16 years, it presented a gestation of 14 months. There was not occurrence of the natural childbirth, being necessary the human intervention through obstetric maneuvers for the retreat of the fetus. The described procedures can be used as reference in other cases of dystocia with the species.

- by Venancio Guedes de Azevedo
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- Elasmobranchs, Captive Breeding, Captive Maintenance
- by Douglas J Long
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- Cetaceans, Chondrichthyes, Sharks, Elasmobranchs

A study of factor which may affect the populations of the smooth freshwater stingray, D. garouaensis was carried out. Populations of the species inhabit the Lokoja section of the River Niger. Habitat modification through river dredging and watershed disruption, urban expansion and development, road construction, pollution, culture and tradition are some of the observed factors which could be affecting the survival of D. garouaensis populations in the Lokoja section of the River Niger.

- by Okey Alum-Udensi
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- Elasmobranchs, ORNAMENTAL FISH AQUACULTURE, Tropical Aquarium Fish

The food habits and predatory interactions of Alligator mississippiensis (Ameri-can Alligator) have been thoroughly studied within populations inhabiting inland freshwater ecosystems; however, it is increasingly evident that coastal populations habitually forage in estuarine and nearshore marine ecosystems inhabited by other top predators. While few studies have been performed, data reported thus far from marine-foraging populations indicate individuals chiefly consume small-bodied prey such as crustaceans, fish, and wading birds. Nonetheless, capture and consumption of large-bodied marine prey such as multiple species of sea turtles and a single species of Elasmobranchii (sharks and rays) have been documented. Here, we examine evidence regarding reciprocal intraguild predation between American Alligators and elasmobranchs. We provide the first evidence of American Alligator depredation of 4 Elasmobranchii species and review putative evidence for Elas-mobranchii depredation of American Alligators. We discuss the ecological significance of these interactions, draw comparisons to similar interactions experienced by other crocodil-ians, and recommend further avenues for research on the subject.

- by James C Nifong
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- Crocodylians, Predator-Prey Interactions, Elasmobranchs
- by Paola Andrea Mejía-Falla
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- Marine Biology, Sharks, Elasmobranchs, Rays

The discovery of deep-sea hydrothermal vents in 1977 challenged our views of ecosystem functioning and yet, the research conducted at these extreme and logistically challenging environments still continues to reveal unique biological processes. Here, we report for the first time, a unique behavior where the deep-sea skate, Bathyraja spinosissima, appears to be actively using the elevated temperature of a hydrothermal vent environment to naturally " incubate " developing egg-cases. We hypothesize that this behavior is directly targeted to accelerate embryo development time given that deep-sea skates have some of the longest egg incubation times reported for the animal kingdom. Similar egg incubating behavior, where eggs are incubated in volcanically heated nesting grounds, have been recorded in Cretaceous sauropod dinosaurs and the rare avian megapode. To our knowledge, this is the first time incubating behavior using a volcanic source is recorded for the marine environment. Despite being the largest biome, the deep sea remains the least explored ecosystem on earth 1,2. In 1977, the discovery of the first deep-sea ecosystems supported by hydrothermal vent fluid emissions at the Galapagos Rift, challenged our views of ecosystem functioning and fueled new hypotheses about how life on earth could have originated around these chemically reactive environments 3–5. Forty years later, we now know that hydrothermal vent ecosystems exist in every ocean basin, supporting rich communities and unique biological processes 6–9. Initially considered isolated patches of life within a barren deep-sea floor, we are beginning to appreciate that these ecosystems interact with the surrounding environment and influence global geochemical cycles 7,8. Most hydrothermal vent sites remain unexplored, and our understanding of the ecology of these ecosystems in most parts of the world remains limited. Furthermore, some of these chemosynthesis based ecosystems are now under threat from human activities and are targeted for exploitation of their mineral resources 10,11. Here, we report for the first time a unique behavior where the Pacific white skate Bathyraja spinosissima, one of the deepest living of all known skate species 12 , uses active hydrothermal vent fields as a natural incubator for their external egg-capsules. To the best of our knowledge and understanding, this is the first time this incubating behavior at an active hydrothermal vent field has been recorded for a species within the marine environment. The Galapagos Platform in the eastern tropical Pacific consists of 13 major volcanic islands and numerous seamounts that straddle the equator 13. To the north of the archipelago and parallel to the equator, the Galapagos Spreading Center (GSC) extends for over 1000 km west to east, crossing the Galapagos Marine Reserve north of Darwin Island (Fig. 1). Previous exploration of the area revealed the presence of active hydrothermal vents,

- by Pelayo Salinas de León and +2
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- Evolutionary Biology, Marine Ecology, Marine Protected Areas, Fish Biology

1. Encabezado. El encabezado llevará el logotipo de la institución, datos e instrucciones generales (ver Anexo) todo en mayúsculas. En el apartado de instrucciones generales, se deberá especificar el uso de calculadora o formulario, así... more

- by Oscar Huchin
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- Elasmobranchs, Lineamientos, Pruebas

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 publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2014, list of descriptions of extinxt and extant species from 2014, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information.

- by Jürgen Pollerspöck
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- Fossil Elasmobranchii, Chondrichthyes, Sharks, Fossil sharks

Professionals who care for sharks, skates, and rays in controlled environments must become knowledgeable about the biology and behavior of the animals within their care and develop a familiarity with the behavior of individual specimens. Natural behaviors can be encouraged by the implementation of behavioral enrichment programs, including animal training through operant conditioning. Training programs can reduce stress in situations where animals must be moved or handled, assist with basic husbandry procedures, and enhance public and educational displays. Since these factors contribute to improving the overall health and welfare of animals in controlled environments, animal training through operant conditioning is an important enrichment tool for facilities that exhibit elasmobranchs.

- by Carlos A . Bohorquez R.
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- Marine Biology, Sharks, Elasmobranchs, Rays
- by Jimena Bohórquez-Herrera
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- Marine Biology, Sharks, Elasmobranchs, Fisheries Bycatch

La Fundación Malpelo, ha sido pionera en Colombia en el uso de nuevas técnicas para el estudio de las poblaciones de tiburones;
tal como la telemetría acústica. Con el objetivo de determinar si hay residencia de las especies Triaenodon obesus y Carcharhinus
galapagensis en el Santuario de Flora y Fauna Isla de Malpelo, se usaron tags acústicos V16 y receptores localizados alrededor de la isla, determinando patrones y diferencias para estas especies.

- by Alexandra Pineda-Muñoz
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- Underwater Acoustics, Shark conservation, Sharks, Elasmobranchs

This paper contains a collection of 722 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 2018. The list is the result of regular queries in numerous journals, books and online publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2018, list of descriptions of extinct and extant species from 2018, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide data information on the geographic and depth distribution of newly described species, i.e. the type specimens from the years 1990 to 2018 in a hot spot analysis. The subheader "biodiversity" comprising a complete list of all valid chimaeriform, selachian and batoid species, as well as a list of the top 20 most researched chondrichthyan species. Please note that the content of this paper has been compiled to the best of our abilities based on current knowledge and practice, however, possible errors cannot entirely be excluded.

- by Jürgen Pollerspöck
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- Parasitology, Fossil Fish, Chondrichthyes, Sharks

The bull shark (Carcharhinus leucas Valenciennes, 1839) is a large, primarily coastally distributed shark famous for its ability to penetrate far into freshwater bodies in tropical, subtropical, and warm-temperate climates. It is a cosmopolitan species with a geographical range that includes the coastlines of all major ocean basins (Atlantic
Ocean, Indian Ocean, Pacific Ocean). As a consequence, freshwater occurrences of C. leucas are possible everywhere inside its geographic range. Carcharhinus leucas is a fully euryhaline, amphidromous species and possibly the widest-ranging of all freshwater tolerating elasmobranchs. This species is found not only in river systems with sea access that are not interrupted by human impediments but in hypersaline lakes as well. Rivers and estuaries are believed to be important nursery grounds for C. leucas, as suggested by observations of pregnant females in estuaries and neonates with umbilical scars in rivers and river mouths. Due to the physical capability of this species to enter riverine systems, the documentation of its occurrence in fresh and brackish water is essential for future conservation plans, fishery inspections, and scientific studies that focus on the link between low salinity habitats, shark nurseries, and feeding areas. The author’s review of the available literature on C. leucas revealed the absence of a comprehensive overview of fresh and brackish water localities (rivers and associated lakes, estuaries) with C. leucas records. The purpose of this literature review is to provide a global list of rivers, river systems, lakes, estuaries, and lagoons with records and reports of this species, including a link to the used references as a base for regional, national, and international conservation strategies. Therefore, the objective of this work is to present lists of fresh and brackish water habitats with records of C. leucas as the result of an extensive literature review and analysis of
databases. This survey also took into account estuaries and lagoons, regarding their function as important nursery grounds for C. leucas. The analysis of references included is not only from the scientific literature, but also includes semi-scientific references and the common press if reliable. The result of 415 global fresh and brackish water localities with evidence of C. leucas highlights the importance of these habitats for the reproduction of this species. Moreover, gaps in available distribution maps are critically discussed as well as interpretations and conclusions made
regarding possible reasons for the distribution range of C. leucas, which can be interpreted as the result of geographic circumstances, but also as a result of the current state of knowledge about the distribution of this species. The results of the examination of available references were used to build a reliable and updated distribution map for C. leucas, which is also presented here.

- by Peter Gausmann
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- DISTRIBUTION, Chondrichthyes, Shark conservation, Sharks

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 provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2017, list of descriptions of extinct and extant species from 2017, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide data information on the geographic and depth distribution of newly described species, i.e. the type specimens from the years 1990 to 2017 in a hot spot analysis. New in this year's POTY is the subheader "biodiversity" comprising a complete list of all valid chimaeriform, selachian and batoid species, as well as a list of the top 20 most researched chondrichthyan species.

- by Jürgen Pollerspöck
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- Parasitology, Fossil Fish, Chondrichthyes, Sharks
- by Jimena Bohórquez-Herrera
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- Marine Biology, Sharks, Elasmobranchs, Identification Guide

This paper contains a collection of 807 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 2019. The list is the result of regular queries in numerous journals, books and online publications. It provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2019, list of descriptions of extinct and extant species from 2019, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide data information on the geographic and depth distribution of newly described species, i.e. the type specimens from the years 1990 to 2019 in a hot spot analysis. The subheader "biodiversity" comprising a complete list of all valid chimaeriform, selachian and batoid species, as well as a list of the top 20 most researched chondrichthyan species.

- by Jürgen Pollerspöck
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- Fossil Fish, Chondrichthyes, Sharks, Elasmobranchs

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 provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2016, list of descriptions of extinct and extant species from 2016, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide information on the geographic and depth distribution of newly described species, i.e. the type specimens from the year 1990- 2016 in a hot spot analysis.
Please note that the content of this paper has been compiled to the best of our abilities based on current knowledge and practice, however, possible errors cannot entirely be excluded.

- by Jürgen Pollerspöck and +1
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- Great white shark, Fossil Fish, Chondrichthyes, Shark conservation
- by Alex Tilley
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- Marine Ecology, Elasmobranchs, Latin America and the Caribbean, Stingrays

This document entitled “Guidance on National Plan of Action for Sharks in India” is intended as a guidance to the NPOA-Sharks, and seeks to (1) present an overview of the current status of India’s shark fishery, (2) assess the current management measures and their effectiveness, (3) identify the knowledge gaps that need to be addressed in NPOA-Sharks and (4) suggest a theme-based action plan for NPOA-Sharks.

- by Shoba Kizhakudan and +2
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- Fisheries Management, Marine and Fisheries Policy, Shark conservation, Sharks

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 provides a complete list of publication citations as well as a database report containing rearranged subsets of the list sorted by the keyword statistics, extant and extinct genera and species descriptions from the years 2000 to 2015, list of descriptions of extinct and extant species from 2015, parasitology, reproduction, distribution, diet, conservation, and taxonomy. The paper is intended to be consulted for information. In addition, we provide information on the geographic and depth distribution of newly described species, i.e. the type specimens from the year 1990- 2015 in a hot spot analysis.

- by Jürgen Pollerspöck
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- Fossil Elasmobranchii, Chondrichthyes, Sharks, Fossil sharks

El trabajo de grado titulado "Aspectos biológicos y pesqueros de elasmobranquios capturados en el Parque Nacional Natural Gorgona y su área de influencia entre 2004 y 2005" presentado por la estudiante JIMENA BOHÓRQUEZ HERRERA como... more

- by Jimena Bohórquez-Herrera
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- Marine Biology, Fisheries, Biology, Sharks

This collection is the result of research in numerous journals, books and online publications. It contains 721 citations of papers about living/fossil sharks, rays and chimaeras (Chondrichtyes: Elasmobranchii, Holocephali) and a list of... more

- by Jürgen Pollerspöck
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- Sharks, Elasmobranchs, Rays, Chimaera

Hiu karet (Prionace glauca) adalah hiu pelagis yang menjadi target tangkapan nelayan artisanal Tanjung Luar dan umumnya tertangkap di Samudera Hindia Selatan Nusa Tenggara. Penelitian ini bertujuan untuk mengetahui sebaran ukuran dan beberapa parameter populasi hiu karet (Prionace glauca) yang tertangkap di perairan selatan Nusa Tenggara. Analisis dilakukan terhadap 1.414 ekor hiu karet yang tertangkap rawai hanyut di selatan Nusa Tenggara dan didaratkan di Tanjung Luar, Lombok Timur selama periode 2014 – 2016. Analisis data dilakukan secara deskriptif dan beberapa parameter populasi diduga menurut rumus empiris Froese & Binohlan (2000). Hasil penelitian menunjukkan sebaran ukuran panjang total hiu karet berkisar antara 95 – 383 cm (jantan) dan 113 – 333 cm (betina) dengan rerata ukuran yang tertangkap tidak berbeda nyata. Nisbah kelamin didominasi oleh hiu karet jantan dan telah matang kelamin. Dugaan terhadap beberapa parameter adalah: nilai L∞ antara 333,02 - 385,59 cm dengan Lm jantan antara 187,21 – 215 cm dan betina 139,82 – 159,34 cm. Sebanyak 39,96 – 44,71% hiu karet tertangkap pada panjang optimumnya sehingga ada kecenderungan tangkap lebih.

- by Agus Arifin Sentosa and +1
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- Fisheries Science, Fisheries, Fisheries Management, Fish Biology
- by Carlo Romano and +1
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- Fossil Elasmobranchii, Chondrichthyes, Triassic, Elasmobranchs

Hiu macan atau tiger shark (Galeocerdo cuvier Peron & Lesuer, 1822) banyak tertangkap di perairan Samudera Hindia. Status konservasinya masuk dalam Daftar merah IUCN dan hampir terancam (NT). Tujuan penelitian adalah untuk mendapatkan informasi parameter populasi hiu macan di perairan Samudera Hindia bagian Selatan Nusa Tenggara Barat. Penelitian dilakukan di tempat pendaratan ikan Tanjung Luar, Lombok Timur pada bulan Januari sampai dengan Desember 2016 menggunakan metode survei. Hasil penelitian terhadap 808 ekor ikan contoh menunjukkan bahwa kisaran panjang total untuk hiu macan (Galeocerdo cuvier) antara 116 - 400 cmTL. Perbandingan kelamin ikan hiu macan jantan dan betina dalam keadaan tidak seimbang, dengan jumlah betina lebih besar. Estimasi panjang asimtotik (L∞) sebesar 420 cmTL dengan laju pertumbuhan (K) sebesar 0,260/tahun, laju kematian total (Z) sebesar 1,10/tahun, laju kematian alamiah (M) sebesar 0,35/tahun serta laju kematian akibat penangkapan (F) sebesar 0,75/tahun. Estimasi laju eksploitasi sudah berada pada penangkapan yang berlebih (E = 0,68) oleh karena itu perlu dilakukan tindakan pengelolaan agar pemanfaatannya tetap lestari.
KATA KUNCI : parameter, populasi, hiu macan, Galeocerdo cuvier, Nusa Tenggara Barat

- by Agus Arifin Sentosa
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- Fisheries Science, Fisheries Management, Fish Biology, Fisheries Biology

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 records in total. This edition contains 2,036 different species of parasites recovered from 495 species of elasmobranchs. All information about the parasites are also available at http://shark-references.com/species/host-parasites-list/A or http://shark-references.com/species/parasite-hosts-list/A (weekly update).

- by Jürgen Pollerspöck
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- Parasitology, Chondrichthyes, Sharks, Fish Parasites

Several factors that influence the evolution of the unusual head morphology of hammerhead sharks (family Sphyrnidae) are
proposed but few are empirically tested. In this study we tested the ‘enhanced binocular field’ hypothesis (that proposes
enhanced frontal binocularity) by comparison of the visual fields of three hammerhead species: the bonnethead shark, Sphyrna
tiburo, the scalloped hammerhead shark, Sphyrna lewini, and the winghead shark, Eusphyra blochii, with that of two carcharhinid
species: the lemon shark, Negaprion brevirostris, and the blacknose shark, Carcharhinus acronotus. Additionally, eye rotation
and head yaw were quantified to determine if species compensate for large blind areas anterior to the head. The winghead shark
possessed the largest anterior binocular overlap (48deg.) and was nearly four times larger than that of the lemon (10deg.) and
blacknose (11deg.) sharks. The binocular overlap in the scalloped hammerhead sharks (34deg.) was greater than the bonnethead
sharks (13deg.) and carcharhinid species; however, the bonnethead shark did not differ from the carcharhinids. These results
indicate that binocular overlap has increased with lateral head expansion in hammerhead sharks. The hammerhead species did
not demonstrate greater eye rotation in the anterior or posterior direction. However, both the scalloped hammerhead and
bonnethead sharks exhibited greater head yaw during swimming (16.9deg. and 15.6deg., respectively) than the lemon (15.1deg.)
and blacknose (15.0deg.) sharks, indicating a behavioral compensation for the anterior blind area. This study illustrates the larger
binocular overlap in hammerhead species relative to their carcharhinid sister taxa and is consistent with the ‘enhanced binocular
field’ hypothesis.

- by Mikki McComb-Kobza
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- Elasmobranchs, Sensory Biology, Hammerhead Sharks

The yellow stingray, Urobatis jamaicensis (family Urolophidae), a short-lived, relatively small elasmobranch species (35--40 cm total length), is a common inhabitant of hard bottom and coral reef communities in southeastern Florida and many parts of the Caribbean. A paucity of published studies deal with the yellow stingray, none however on the gross morphology of its nervous system. The gross brain structure of the yellow stingray is compared with previously published studies on other batoid elasmobranchs. The external brain structure of Urobatis jamaicensis was similar to that reported for other Dasyatids, including presence of an asymmetric cerebellum. The bilaterally symmetric brain is well developed and quite large in proportion to body size (≈1--2% bw). Stingrays generally possess a brain three to 10 times the size of their sister groups, the electric rays, guitarfish, and skates , the yellow stingray is no exception.

- by Anna Michel
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- Marine Biology, Fish Biology, Elasmobranchs

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 series of dental identification keys. Herein, lamniform sharks are in focus. Today, the order Lamniformes comprises 15 species in 10 genera and 7 families. All of these large active pelagic sharks have a worldwide geographic distribution. The key is essentially based on the following characters: dental formula, presence/absence of specific categories of teeth ((para-)symphyseal, intermediate teeth), form of crown, number of cusplets, and dentition type. The key allows the identification to genus and species level, if adequate specimens are available. It is further supplemented by a detailed species account. The glossary presented in part A of this series extended by some terms that are specific for lamiform sharks. Zusammenfassung: In zahlreichen wissenschaftlichen Sammlungen befinden sich neben formaldehyd-bzw. alkoholkonservierten Ganzkörper-und anatomischen Präparaten oftmals Kiefer und Zähne von Haien und Rochen. Bei diesen Exemplaren fehlen häufig detaillierte Informationen über die Art, das Geschlecht oder die geografische Herkunft. Mit der vorliegenden Arbeit wird ein weiterer Teil eines Bestimmungsschlüssels für Kiefer und Zähne von lamniformen Haien vorgestellt (Teil B der geplanten Reihe). Diese Ordnung beinhaltet derzeit 15, meist großwüchsige, weltweit verbreitete pelagische Arten in zehn Gattungen und sieben Familien. Zur Identifizierung wird dabei im Wesentlichen auf folgende Merkmale zurückgegriffen: Zahnformel, An-oder Abwesenheit bestimmter Zahngruppen ((Para-) Symphysenzähne, Intermediärzähne), Form der Krone, Anzahl der Zahnspitzen und Art der Bezahnung. Der Schlüssel ermöglicht die Bestimmung bis auf Artebene. Ergänzt wird er durch eine detaillierte Artbeschreibung in Bezug auf zahnmorphologische Merkmale. Das im ersten Teil vorgestellte Glossar wird um einige Begriffe, die für diese lamniformen Haie von Bedeutung sind, erweitert.

- by Jürgen Pollerspöck
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- Sharks, Elasmobranchs, Guide

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 collection site is a clay pit in between the Lower Bavarian villages Fürstenzell and Schmidham. The sample revealed 14 shark and four ray species. We present the first record of fossils assigned to taxa Nanocetorhinus tuberculatus, Deania and Apristurus from Germany. In addition, we describe a hitherto unknown genus and species of shark, Pseudoapristurus nonstriatus gen. et sp. nov., based on fossil teeth. The documented diversity is compared to both extant and fossil records of neoselachian deep-water diversities, and it is evident that this Miocene fauna is very similar in composition to indo-pacific deep-water assemblages. Zusammenfassung Aus der Oberen Meeresmolasse (Neuhofener Schichten, unteres Ottnangium) Niederbayerns (Tongrube zwischen Fürstenzell und Schmidham) wird eine artenreiche Tiefwasser-Elasmobranchierfauna beschrieben. Insgesamt werden 14 Hai-und vier Rochenarten nachgewiesen. Erstnachweise für Deutschland werden von Nanocetorhinus tuberculatus, Apristurus sp. und Deania sp. erbracht. Zusätz-lich wird eine bisher unbekannte Neoselachier Gattung und Art (Pseudoapristurus nonstriatus nov. gen. et sp.) anhand von Zahnfossilien beschrieben. Ein Vergleich der hier dokumentierten Diversität mit verschiedenen anderen rezenten und fossilen Neoselachier Vergesell-schaftungen zeigt, dass die vorliegende Fauna große Übereinstimmungen mit rezenter indo-pazifischer Tiefseediversität aufweist.

- by Jürgen Pollerspöck
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- Fossil Fish, Sharks, Elasmobranchs, Fossils

There are few studies investigating captive conditions for commonly kept public aquaria species. Here the thornback ray (Raja clavata) was used to determine preferred captive conditions via choice tests and behavioural observations. Substrate type, substrate colour, substrate depth, group size and refuge use were all used to assess usage, number of stereotypic behaviours and activity in captive born rays. Sand was the preferred choice of substrate which also brought fewer surface breaking behaviours (a possible stereotypic behaviour) compared to gravel or bare tanks. Lighter colours of sand were preferred, as were deeper depths whilst increasing group size increased possible stereotypic behaviours. Type of resting behaviour (horizontal vs vertical) also differed within experiments − rays switched from horizontal to vertical resting, on the side of the tank when using gravelled versus sandy areas of the tank. The rays in this study appeared not to use refuges. Very few published studies have focused on what aquatic animals want, here we use preference tests, which are a useful way of determining what the animal wants, and can help aquarists provide the best conditions for captive thornback rays.

- by Gavan Cooke
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- Zoology, Animal Welfare, Environmental enrichment, Elasmobranchs
- by Paola Andrea Mejía-Falla
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- Marine Biology, Sharks, Elasmobranchs, Rays

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 scarce, incomplete or incorrect. The identification key for jaws and teeth presented herein focuses on squalomorph sharks, which comprise almost 34 % of all sharks with 179 species in 31 genera and 11 families. The key is essentially based on the following characters: vascularisation stage, labial apron, number of cusplets, distal heel, lingual ornamentation, cutting edge, and dentition kind. The key allows the identification to genus level. It is further supplemented by a comprehensive glossary of tooth morphological terms as well as an updated checklist of all currently described squalomorph sharks with indication of the distribution and the dental formula. Zusammenfassung: In zahlreichen wissenschaftlichen Sammlungen befinden sich neben formaldehyd-oder alkoholkonservierten Ganzkörper-und anatomischen Präparaten oftmals Kiefer und Zähne von Haien und Rochen. Diese Exemplare stammen häufig aus historischen Sammlungen und die vorhandenen Informati-onen über die Art, das Geschlecht oder die geografische Herkunft sind oftmals lückenhaft oder falsch. Mit der vorliegenden Arbeit wird ein Bestimmungsschlüssel für Kiefer und Zähne von squalomorphen Haien vorgestellt. Diese Überordnung beinhaltet derzeit 179 Arten in 31 Gattungen und 11 Familien und stellt damit annähernd fast 34 % aller heute bekannten Haiarten dar. Zur Identifizierung wird dabei im Wesentlichen auf folgende Merkmale zurückgegriffen: Art des Vaskularisationssystems, labiales Apron, Anzahl der Zahn-spitzen, Talon, linguale Ornamentik, Form der Schneide und Art der Bezahnung. Der Schlüssel ermöglicht die Bestimmung bis auf Gattungsebene. Ergänzt wird er durch ein umfangreiches Glossar der wichtigsten zahnmorphologischen Begriffe sowie eine aktualisierte Checkliste aller derzeit bekannten squalomorphen Haie mit Angabe der geographischen Verbreitung und der Zahnformel.

- by Jürgen Pollerspöck
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- Chondrichthyes, Sharks, Elasmobranchs, Tooth

Here we describe a new elasmobranch assemblage consisting of isolated dental material from the Aquitanian near-shore marine deposits of the Shuwayr and Warak formations at Sharbithat, in eastern Sultanate of Oman. The faunal composition clearly indicates affinities to other early Miocene elasmobranch-bearing localities worldwide. This assemblage is predominantly composed of large and common pelagic sharks as well as teeth attributable to a new species of fantail stingray, Taeniurops tosii, as old as the oldest undisputable fossil records of Taeniurops. The study of this fossil assemblage presented here improves the knowledge of the ancient elasmobranchs that frequented the eastern Arabian coasts during the closure of the Neotethys and the birth of the Arabian Sea.

- by Geologica Acta
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- Elasmobranchs, Neogene, New Species, Arabian Sea

Elasmobranch remains are quite common in Miocene deposits and were the subject of numerous studies since the middle of the nineteenth century. Nevertheless, the taxonomic diversity of the Marine Molasse sharks, rays and skates is still largely unknown. Here, we describe 37 taxa from the lower Miocene of the Molasse Basin: 21 taxa could be identified at species level, whereas 15 taxa could only be assigned to genus and one taxon is left as order incertae sedis. The material was collected from deposits of the Auwiesholz Member of the Achen Formation (middle Burdigalian, middle Ottnangian age, ca. 17.8 Ma) exposed near Simssee, Upper Bavaria. This faunal assemblage is a mixture of shallow marine, near-coastal, pelagic and deep-water taxa. The fauna from Simssee displays different biogeographic dynamics at local and regional scales, possibly related to the intense climatic, oceanographic and tectonic events that occurred during the Eggenburgian-Ottnangian stages. The faunal relationships of the early Miocene chondrichthyan faunas from the Mediterranean Sea and Paratethys with others regions are established on the basis of qualitative (presence/absence) data. The beta diversity (Sørensen-Dice coefficient) of the Miocene Molasse elasmobranchs was used to characterize the taxonomic differentiation between localities and regions. According to our results, the fauna from Simssee shows close similarities with those from Switzerland, Austria, France and northern Germany. Faunal similarities and differences are mainly related to tectonic events and oceanographic variables (i.e. migration through seaway passages) or might represent collecting biases.

- by Jürgen Pollerspöck and +1
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- Fossil Elasmobranchii, Fossil Fish, Chondrichthyes, Sharks

On 10 March 2017, thirty individuals of giant devil ray, Mobula mobular, were caught accidentally by a commercial purse seiner at a depth of approximately 25 m off Beşadalar, the Gulf of Antalya. Of the thirty specimens, two are described... more

- by Elif Özgür
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- Marine Biology, Chondrichthyes, Sharks, Elasmobranchs

Penelitian ini bertujuan untuk mengetahui keragaman laju penangkapan Elasmobranchii pada berbagai alat tangkap yang dioperasikan oleh nelayan Tanjung Luar. Penelitian dilakukan selama bulan Januari hingga November 2016. Data diperoleh dengan bantuan enumerator yang mencatat jumlah dan jenis alat tangkap beserta kapal yang mengoperasikannya, total ekor dan bobot hasil tangkapan nelayan Tanjung Luar setiap bulan. Analisis dilakukan berdasarkan laju tangkap dengan rumus hasil tangkapan per satuan upaya (CPUE) berbasis ekor dan biomassa tangkapan. Hasil menunjukkan terdapat 12 variasi alat tangkap yang digunakan oleh nelayan Tanjung Luar yang merupakan perpaduan antara jaring insang/gillnet, rawai, pancing dan pukat cincin. Rerata laju tangkap individu tertinggi dimiliki oleh armada kapal yang mengoperasikan alat tangkap perpaduan gillnet dan rawai (dasar dan hanyut) sebesar 4,51 ekor/kapal/bulan sementara rerata laju tangkap biomassa tertinggi dimiliki oleh armada kapal yang mengoperasikan alat tangkap perpaduan gillnet dan rawai hanyut sebesar 103,93 kg/kapal/bulan. Laju tangkap Elasmobranchii bervariasi tergantung jenis alat tangkap, metode operasional dan jumlah kapal yang beroperasi.

- by Agus Arifin Sentosa
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- Fisheries Science, Fisheries, Shark conservation, Sharks

Os peixes formam o grupo de vertebrados com maior número de espécies que todos os outros vertebrados em conjunto. Habitam os mais diversos tipos de ambientes, mas para isso foram necessários milhões de anos de evolução e impressionantes adaptações morfológicas, funcionais e fisiológicas. Algumas destas adaptações e suas funções associadas serão apresentadas a seguir. Este artigo foi elaborado para oferecer um material atualizado e ilustrado sobre as diferentes formas do corpo, revestimentos, nadadeiras, bocas, dentes, olhos e suas diversas adaptações morfológicas e anatômicas. O objetivo foi de produzir um material didático-pedagógico visando explorar as imagens que contribuem à compreensão do texto, de forma a atender às necessidades das disciplinas de Biologia e Ciências, no contexto do assunto “Peixes”.

- by Luciano Gomes Fischer and +1
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- Ichthyology, Functional Morphology, Morphology, Fish Biology

The banded guitarfish (Zapteryx exasperata) is a commercially-important species in the Northwest artisanal ray fishery of Mexico. However, very little information about its fisheries characteristics and catch abundance is available. Seasonal sampling was conducted between 1998─2000 and 2004─2005 in five fishery camps in the Gulf of California. Z. exasperata is a secondary resource in ground fisheries, and is caught using gill nets with mesh sizes between 15─20 cm from small fiberglass boats called “pangas,” fishing between 4─54 m depth. Catches were composed of individuals between 41.3─90 cm TL with an average weight of 2.18  1.13 kg. The sex ratio of the catches was 1:1. Females reached larger sizes and weights than males; therefore, the morphometric relationships were different between sexes. CPUE reached its highest values during spring (3.4 ind/trip), and was lowest during summer. CPUE was also higher in fishing sites with depths between 100─200 m (5.5 ind/trip). Z. exasperata fishery characteristics are similar to those reported for elasmobranchs in other regions of Mexico. In particular, the seasonality of the catches was similar to that reported for other ray species in the Gulf of California, with a peak during spring and summer.

- by Maria-del-Pilar Blanco-Parra
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- Fisheries, Morphology, Elasmobranchs