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Marcelo R. De Carvalho - One of the best experts on this subject based on the ideXlab platform.
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Comparative morphology and systematics of the cookiecutter sharks, genus Isistius Gill (1864) (Chondrichthyes: Squaliformes: Dalatiidae)
PloS one, 2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:The dalatiid genus Isistius Gill (1864) has three valid species currently recognized in the literature: Isistius brasiliensis Quoy & Gaimard (1824), I. plutodus Garrick & Springer (1964), and I. labialis Meng, Zhu & Li (1985). The most common species, I. brasiliensis, has a wide geographic distribution and is found in subtemperate and tropical seas circumglobally. A comparative analysis of specimens from different localities throughout its range, however, had never been undertaken. In the present paper, the morphological variation of this species along its entire distribution has been thoroughly analyzed, corroborating that it represents a single widespread species and that I. labialis is its junior synonym. The other congeneric species, I. plutodus, is known from only a few specimens and is also distributed worldwide. A detailed comparative analysis of available material of I. plutodus was conducted verifying its validity as a single widespread species. The present study analyzed in detail the external morphology (coloration, dentition, dermal denticles), internal morphology (skeleton, musculature), lateral-line canals, and morphometric and meristic characters of species of Isistius in order to better define the genus and its included valid species.
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Specimen of Isistius brasiliensis (SCSFRI S07257).
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:Holotype of the junior synonym Isistius labialis Meng, Zhu & Li (1985) [17]. From South China Sea, Pacific Ocean. TL = 442 mm. Left lateral view.
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Mandibular and hyoid arches of Isistius plutodus (ZUEC 8333).
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:(A) dorsal (anterior to top), (B) anterior (dorsal to top), and (C) left lateral views. Note lmh missing from left side in (A), and ceratohyal and hyomandibula missing from left side in (B). Abbreviations: bh, basihyal; cch, large concavities on ceratohyal; ch, ceratohyal; hm, hyomandibula; lmh, ligamentum mandibulo-hyoideum; ma, mandibula; mad, articular fossa; mfl, mandibular accessory cartilage; mk, mandibular knob; op, orbital process; otf, otic flange; pap, palatine plate; pqc, quadrate plate concavity; pqd, quadrate plate condyle; qup, quadrate plate.
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Mandibular and hyoid arches of Isistius brasiliensis (MZUSP 121506).
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:(A) dorsal (anterior to top), (B) posterior (dorsal to top), and (C) left lateral views. Note lmh missing from left side in (A), and ceratohyal and hyomandibula missing from right side in (B). Abbreviations: bh, basihyal; cch, large concavities on ceratohyal; ch, ceratohyal; hm, hyomandibula; lmh, ligamentum mandibulo-hyoideum; ma, mandibula; mad, articular fossa; mfl, mandibular accessory cartilage; mk, mandibular knob; op, orbital process; otf, otic flange; pap, palatine plate; pqc, quadrate plate concavity; pqd, quadrate plate condyle; qup, quadrate plate.
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Comparative morphology and systematics of the cookiecutter sharks, genus Isistius Gill (1864) (Chondrichthyes: Squaliformes: Dalatiidae) - Fig 35
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:Pectoral girdle (A, B, C) and left pectoral fin (D) of Isistius brasiliensis (MNHN 1996–0465). (A) dorsal view (anterior to top); (B) lateral view (dorsal region to top); (C) ventral view (anterior to top); (D) left pectoral fin in lateral view (anterior to left). Abbreviations: cde, pectoral condyle; cor, coracoid bar; df, diazonal foramen; dr, distal radial; mr, medial radial; mta, metapterygial axis; ptp, posterior triangular process of coracoid bar; pr, proximal radial; pro+mes+met, fused propterygium, mesopterygium, and metapterygium; scp, scapular process.
Flávia De Figueiredo Petean - One of the best experts on this subject based on the ideXlab platform.
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Comparative morphology and systematics of the cookiecutter sharks, genus Isistius Gill (1864) (Chondrichthyes: Squaliformes: Dalatiidae)
PloS one, 2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:The dalatiid genus Isistius Gill (1864) has three valid species currently recognized in the literature: Isistius brasiliensis Quoy & Gaimard (1824), I. plutodus Garrick & Springer (1964), and I. labialis Meng, Zhu & Li (1985). The most common species, I. brasiliensis, has a wide geographic distribution and is found in subtemperate and tropical seas circumglobally. A comparative analysis of specimens from different localities throughout its range, however, had never been undertaken. In the present paper, the morphological variation of this species along its entire distribution has been thoroughly analyzed, corroborating that it represents a single widespread species and that I. labialis is its junior synonym. The other congeneric species, I. plutodus, is known from only a few specimens and is also distributed worldwide. A detailed comparative analysis of available material of I. plutodus was conducted verifying its validity as a single widespread species. The present study analyzed in detail the external morphology (coloration, dentition, dermal denticles), internal morphology (skeleton, musculature), lateral-line canals, and morphometric and meristic characters of species of Isistius in order to better define the genus and its included valid species.
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Caudal fins of species of Dalatiidae.
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:(A) Isistius brasiliensis (HUMZ 211104); (B) I. plutodus (HUMZ 210817); (C) Dalatias licha (AMS 12876); (D) Squaliolus laticaudus (MNRJ 30199); (E) S. aliae (NSMT-P 35505); (F) Euprotomicrus bispinatus (NSMT-P 71062); (G) Euprotomicroides zantedeschia (ZMH 114732); (H) Heteroscymnoides marleyi (ZMH 108438); (I) Mollisquama parini (TU 203676).
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Specimen of Isistius brasiliensis (SCSFRI S07257).
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:Holotype of the junior synonym Isistius labialis Meng, Zhu & Li (1985) [17]. From South China Sea, Pacific Ocean. TL = 442 mm. Left lateral view.
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Mandibular and hyoid arches of Isistius plutodus (ZUEC 8333).
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:(A) dorsal (anterior to top), (B) anterior (dorsal to top), and (C) left lateral views. Note lmh missing from left side in (A), and ceratohyal and hyomandibula missing from left side in (B). Abbreviations: bh, basihyal; cch, large concavities on ceratohyal; ch, ceratohyal; hm, hyomandibula; lmh, ligamentum mandibulo-hyoideum; ma, mandibula; mad, articular fossa; mfl, mandibular accessory cartilage; mk, mandibular knob; op, orbital process; otf, otic flange; pap, palatine plate; pqc, quadrate plate concavity; pqd, quadrate plate condyle; qup, quadrate plate.
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Mandibular and hyoid arches of Isistius brasiliensis (MZUSP 121506).
2018Co-Authors: Flávia De Figueiredo Petean, Marcelo R. De CarvalhoAbstract:(A) dorsal (anterior to top), (B) posterior (dorsal to top), and (C) left lateral views. Note lmh missing from left side in (A), and ceratohyal and hyomandibula missing from right side in (B). Abbreviations: bh, basihyal; cch, large concavities on ceratohyal; ch, ceratohyal; hm, hyomandibula; lmh, ligamentum mandibulo-hyoideum; ma, mandibula; mad, articular fossa; mfl, mandibular accessory cartilage; mk, mandibular knob; op, orbital process; otf, otic flange; pap, palatine plate; pqc, quadrate plate concavity; pqd, quadrate plate condyle; qup, quadrate plate.
Theoni Photopoulou - One of the best experts on this subject based on the ideXlab platform.
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Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp
PLoS ONE, 2016Co-Authors: Peter B Best, Theoni PhotopoulouAbstract:The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei (Balaenoptera borealis), fin (B. physalus), inshore and offshore Bryde’s (B. brydeii sp) and sperm whales (Physeter macrocephalus) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde’s whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males.
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(above) Cod end of an Isaacs-Kidd midwater trawl bitten by captured Isistius brasiliensis (photo J C Staiger, University of Miami, 10 May 1972); (below) plug of fish tissue found in the stomach of an I. brasiliensis caught in Isaacs-Kidd midwater trawl (photo M J Miller, Atmosphere and Ocean Research Institute, University of Tokyo, Japan).
2016Co-Authors: Peter B Best, Theoni PhotopoulouAbstract:(above) Cod end of an Isaacs-Kidd midwater trawl bitten by captured Isistius brasiliensis (photo J C Staiger, University of Miami, 10 May 1972); (below) plug of fish tissue found in the stomach of an I. brasiliensis caught in Isaacs-Kidd midwater trawl (photo M J Miller, Atmosphere and Ocean Research Institute, University of Tokyo, Japan).
Peter B Best - One of the best experts on this subject based on the ideXlab platform.
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Identifying the "demon whale-biter": Patterns of scarring on large whales attributed to a cookie-cutter shark Isistius sp
PLoS ONE, 2016Co-Authors: Peter B Best, Theoni PhotopoulouAbstract:The presence of crater-like wounds on cetaceans and other large marine vertebrates and invertebrates has been attributed to various organisms. We review the evidence for the identity of the biting agent responsible for crater wounds on large whales, using data collected from sei (Balaenoptera borealis), fin (B. physalus), inshore and offshore Bryde’s (B. brydeii sp) and sperm whales (Physeter macrocephalus) examined at the Donkergat whaling station, Saldanha Bay, South Africa between March and October 1963. We then analyse the intensity and trends in its predation on large whales. Despite the scarcity of local records, we conclude that a cookie-cutter shark Isistius sp is the most likely candidate. We make inferences about the trends in (1) total counts of unhealed bitemarks, and (2) the proportion of unhealed bitemarks that were recent. We use day of the year; reproductive class, social grouping or sex; depth interval and body length as candidate covariates. The models with highest support for total counts of unhealed bitemarks involve the day of the year in all species. Depth was an important predictor in all species except offshore Bryde’s whales. Models for the proportion of recent bites were only informative for sei and fin whales. We conclude that temporal scarring patterns support what is currently hypothesized about the distribution and movements of these whale species, given that Isistius does not occur in the Antarctic and has an oceanic habitat. The incidence of fresh bites confirms the presence of Isistius in the region. The lower numbers of unhealed bites on medium-sized sperm whales suggests that this group spends more time outside the area in which bites are incurred, providing a clue to one of the biggest gaps in our understanding of the movements of mature and maturing sperm males.
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(above) Cod end of an Isaacs-Kidd midwater trawl bitten by captured Isistius brasiliensis (photo J C Staiger, University of Miami, 10 May 1972); (below) plug of fish tissue found in the stomach of an I. brasiliensis caught in Isaacs-Kidd midwater trawl (photo M J Miller, Atmosphere and Ocean Research Institute, University of Tokyo, Japan).
2016Co-Authors: Peter B Best, Theoni PhotopoulouAbstract:(above) Cod end of an Isaacs-Kidd midwater trawl bitten by captured Isistius brasiliensis (photo J C Staiger, University of Miami, 10 May 1972); (below) plug of fish tissue found in the stomach of an I. brasiliensis caught in Isaacs-Kidd midwater trawl (photo M J Miller, Atmosphere and Ocean Research Institute, University of Tokyo, Japan).
Jérôme Mallefet - One of the best experts on this subject based on the ideXlab platform.
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photophore distribution and enzymatic diversity within the photogenic integument of the cookie cutter shark Isistius brasiliensis chondrichthyes dalatiidae
Frontiers in Marine Science, 2021Co-Authors: Jérôme Delroisse, Laurent Duchatelet, Patrick Flammang, Jérôme MallefetAbstract:The cookie-cutter shark Isistius brasiliensis (Squaliformes: Dalatiidae) is a deep-sea species that emits a blue luminescence ventrally, except at the level of a black band beneath the jaw. This study aims to investigate the distribution and histology of the light-emitting organs along the shark body, describe the tissue-specific transcriptomes of the non-photogenic and photogenic ventral integument, describe the repertoire of enzyme-coding transcripts expressed in the two integument regions, and analyse the potential expression of transcripts coding for luciferase-like enzymes (i.e., close homologues of known luciferases involved in the bioluminescence of other organisms). Our analyses confirm the black band’s non-photogenic status and photophore absence within this region. The sub-rostral area is the region where the photophore density is the highest. In parallel, paired-end Illumina sequencing has been used to generate pilot transcriptomes, from the black band and the ventral integument tissues of one individual. In total, 68,943 predicted unigenes have been obtained (i.e., 64,606 for the black band transcriptome, 43,996 for the ventral integument transcriptome) with 43,473 unigenes showing significant similarities to known sequences from public databases. BLAST search analyses of known luciferases, coupled with comparative predicted gene expression (i.e., photogenic, non-photogenic), support the hypothesis that the species uses an unknown luciferase system. An enzymatic repertoire was predicted based on the PRIAM database, and Enzyme Commission numbers were assigned for all detected enzyme-coding unigenes. These transcriptomes based on a single specimen, and the predicted enzyme repertoire, constitute a valuable resource for future investigations on the biology of this enigmatic luminous shark.
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Deep-sea sharks: Relation between the liver's buoyancy and red aerobic muscle volumes, a new approach
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2019Co-Authors: Nicolas Pinte, Mathilde Godefroid, Ouissam Abbas, Vincent Baeten, Jérôme MallefetAbstract:Abstract Shark's buoyancy depends on two types of force: (i) the hydrostatic force which is mainly provided by their liver filled with low density lipids and (ii) the hydrodynamic force which is provided by the morphology of their body and fins. Shallow-water shark species are usually negatively buoyant, whereas deep-sea shark species have been suggested to display neutral buoyancy. It has been suggested that species that are close to the neutrality would have less red aerobic muscle fibers. Here, we investigated several liver features (the hepatosomatic index, the oil content and the lipid composition) playing a major role regarding the buoyancy of three deep-sea shark species (Etmopterus molleri, Etmopterus spinax and Isistius brasiliensis) and one shallow-water counterpart (Galeus melastomus). We used FT-Raman and FT-MIR spectroscopy to qualify/quantify the lipid composition of their liver. Our results showed that most deep-sea shark species studied have liver features providing more buoyancy than their shallow-water counterparts, appart from E. molleri which shows liver's features that resemble more shallow-water shark species (e.g. G. melastomus). Finally, data regarding liver features of several deep-sea shark species from the literature were added and the red aerobic muscle distribution/proportion of nine species was measured, to reveal how these parameters might be related. Our results showed that sharks characterized by a liver providing more hydrostatic force possess proportionally less red aerobic muscles than sharks having a liver that contributes less to their buoyancy. Therefore, our results i.e. deep-sea shark displaying less red aerobic muscle with a liver providing more buoyancy, support low metabolic rates hence slow swimming speed.
