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Topologies of the phylogenetic trees used to construct the composite phylogeny. (a) Gilbert (1967: fig. 4) based on morphology; (b) Compagno (1988: fig. 21.10c) based on morphology; (c) Lavery (1992: fig. 1) based on isozymes; (d) Naylor (1992: fig. 3c) based on isozymes; (e) Martin (1993: fig. 1) based on mitochondrial DNA sequences.
Source publication
Abstract Mauro José Cavalcanti (2007)A phylogenetic supertree of the hammerhead sharks (Carcharhiniformes, Sphyrnidae). Zoological Studies 46(1): xxx-xxx. In this study, 5 hammerhead shark phylogenies (based on morphological, isozyme, and mtDNA sequence data) werecombined to generate a complete, well-resolved composite,phylogeny,for the Sphyrnidae...
Contexts in source publication
Context 1
... phylogenetic source trees available for the Sphyrnidae (Fig. 1) were obtained from the literature (Gilbert 1967, Compagno 1988, Lavery 1992, Naylor 1992, Martin 1993, following the protocol proposed by Bininda- Emonds et al. (2003). The phylogenetic hypothesis of Gilbert (1967) was included as a "seed" tree, even though it was not built using a formal cladistic analysis, as recommended by Purvis ...
Context 2
... to the source trees, the topology of the supertree is very similar to that of the tree proposed by Gilbert (1967), from which it differs only in the placement of E. blochii and S. corona (Fig. 1a). The topological structure of the composite phylogeny is also similar to that of the tree presented by Martin (1993), with regard to the relationship between S. media and S. tudes (Fig. ...
Context 3
... of the supertree is very similar to that of the tree proposed by Gilbert (1967), from which it differs only in the placement of E. blochii and S. corona (Fig. 1a). The topological structure of the composite phylogeny is also similar to that of the tree presented by Martin (1993), with regard to the relationship between S. media and S. tudes (Fig. ...
Citations
... blochii, S. mokarran, S. zygaena and the S. lewini-gilberti, group) and the small cephalofoil group (S. tudes, S. corona, S. tiburo and S. media) (Cavalcanti, 2007). Within these groups, the "lewini-gilberti group" is of great interest due to the complexity of species identification. ...
Sphyrna gilberti is a large hammerhead shark described off South Carolina and data distribution on other regions of the Western Atlantic are unknown. An adult male with a total length of 240 cm was collected in 2021 on Campeche, Southwestern Gulf of México. The precaudal vertebral count of the examined individual was 89, and a large head and a robust caudal peduncle were ob-served. This study documents the first record of S. gilberti in Mexican waters.
... Despite the great number of recent phylogenetic appraisals of elasmobranchs, most of them are based solely on molecular data (e.g. Douady et al., 2003;Winchell et al., 2004;Iglésias et al., 2005;Naylor et al., 2005Naylor et al., , 2012aHuman et al., 2006;Vélez-Zuazo & Agnarsson, 2011) and few are focused on relationships at or below the family level (Eitner, 1995;López et al., 2006;Cavalcanti, 2007;Corrigan & Beheregaray, 2009). ...
This is the first study to combine morphological and molecular characters to infer the phylogenetic relationships among catsharks. All currently valid genera classified in the family Scyliorhinidae s.l. and representatives of other carcharhinoid families plus one lamnoid and two orectoloboids were included as terminal taxa. A total of 143 morphological characters and 44 NADH2 sequences were analysed. Parsimony analyses under different weighting schemes and strengths were used to generate hypotheses of phylogenetic relationships. The phylogenetic analysis of 78 terminal taxa, using the combined dataset and weighting each column separately (SEP; k = 3) resulted in one most-parsimonious cladogram of 4441 steps with the greatest internal resolution of clades and strongest support. The main changes in nomenclature and classification are the revised definition and scope of Scyliorhinidae, Apristurus and Pentanchus and the revalidation of Atelomycteridae. The monophyly of Pentanchidae is supported, as is that of most catshark genera. Two new subfamilies of the family Pentanchidae are defined: Halaelurinae subfam. nov. and Galeinae subfam. nov. Our analysis emphasizes the relevance of morphological characters in the inference of evolutionary history of carcharhinoids and sheds light on the taxonomic status of some genera in need of further exploration.
... A pesar de los amplios estudios filogenéticos al interior de la familia, aún no se esclarecen por completo las relaciones entre géneros y especies. Para ello, se han considerado datos morfológicos (Gilbert, 1967;Compagno), moleculares (Naylor;Martin, 1993;Lim et al., 2010) y una combinación de ambos (Cavalcanti, 2007). ...
The dermal denticles are dermal structures present in the group of chondrichthyans, they have a very important role in their biology and they have been used as a taxonomic character that allows to recognize groups or species. Therefore, in the present work, the dermal morphology of the juveniles of two species of shovel sharks, Sphyrna tiburo and
S. vespertina, whose evolutionary origin is related to the closure of the Central American isthmus, is compared. For this, dermal samples (1 cm2) from three body regions were obtained and processed to obtain high resolution images by means of scanning electron microscopy (SEM). The denticles of both species have a common morphological pattern, with variations in the length of the ridge extensions, free area and overlapping of the denticles, and the degree of notoriety of the microstructural ornamentation.
... A pesar de los amplios estudios filogenéticos al interior de la familia, aún no se esclarecen por completo las relaciones entre géneros y especies. Para ello, se han considerado datos morfológicos (Gilbert, 1967;Compagno), moleculares (Naylor;Martin, 1993;Lim et al., 2010) y una combinación de ambos (Cavalcanti, 2007). ...
The morphological study of the chondrichthyes teeth represents an important taxonomic characteristic used for the classification and identification of different species. The teeth of four different species of selacimorphs (Carcharhinus leucas, Galeocerdo cuvier, Rhizoprionodon longurio and Sphyrna sp.) were diaphonized in order to standardize a dental technique for their transparency. By standardizing the Okumura-Aprile technique applied for the dental diaphonization of humans, an optimal diaphonization was obtained in the four species treated with 7 % HCl where the pulp chamber was clearly observed. Therefore, we may conclude that the OkumuraAprile technique is efficient in shark dental diaphonization.
... Determining informative and easily detectable traits is needed to reach that goal. On the other hand, sometimes there is significant disconnect between molecular identity and morphological characteristics (Cavalcanti 2007;Bazsalovicsová et al. 2014), and an amendment in the description of a species becomes paramount. Additionally, in a host-parasite system, the accurate identification of a host not only determines the boundaries of its distribution range but also helps us understand how a given parasite disperses , as well as assessing the degree of host specificity (Caira and Jensen 2001). ...
Correct identification of elasmobranch species is crucial for taxonomic and parasitological research. Although molecular barcoding may be the fastest choice to determine the identity of a given species, robust and fast species level identification in the field using morphological characters is essential. During this study, 389 specimens representing seven stingray species (Brevitrygon walga, Himantura leoparda, H. uarnak, Maculabatis randalli, M. arabica, M. gerrardi and Pateobatis fai) were examined from the Persian Gulf and the Gulf of Oman. A 1044 bp fragment of the NADH2 gene was generated for 50 specimens with representatives of all species. To verify the initial morphological identification and to compare intra- and interspecific differences a Neighbor-Joining analysis was conducted using uncorrected p-distances, whereas the Bayesian Inference was used to examine the relationships among taxa. Two species (M. arabica and M. gerrardi) are documented from the Persian Gulf for the first time. The molecular results provide the first known evidence of the sympatric distribution of M. randalli and M. arabica in the north and northwestern Indian Ocean. The results of the Bayesian Inference support the recent divergence of both species. Based on morphological comparisons and molecular support we suggest that the descriptions of M. randalli and M. arabica have been carried out on heterogeneous type series which has led to inconsistency between molecular identification and diagnostic morphological characteristics. Detailed morphological examination revealed that there is a relation between the type and number of denticles on the mid-dorsal surface of the disc and the color pattern of the tail. To address this taxonomic conflict all type materials should be re-examined. The Bayesian Inference tree showed that all specimens from the Persian Gulf and the Gulf of Oman morphologically resembling B. walga were found to group well outside those of the Indian species (B. imbricata) with an average p-distance of 0.097. The low nucleotide differences among the urogymnid taxa (P. fai and H. leoparda) from the Persian Gulf and the Gulf of Oman and their conspecific specimens in the Indo-West Pacific region revealed that philopatric behaviors may cause considerable gene flow among populations.
... Most of these hypotheses were based on the analysis of morphological data, with a recent outburst of molecular data [1]. Most of the molecular phylogenies are at the order and family level [2][3][4][5][6][7][8]. Species level phylogenies have included a relatively small number of species [4] and typically focused on smaller clades within sharks such as some families or genera [9][10][11]. ...
Elasmobranchs (sharks, rays and skates) are considered as one of the most ancient and successful vertebrate lineages. According to fossil evidence, elasmobranchs were present from the lower Devonian period and diversified during the “Age of Fishes” to become widely distributed and represented by diverse morphological and ecological forms. The elasmobranch lineage has survived four mass extinction events, and the most extant taxa are derivable from Mesozoic forms. Despite a highly successful evolutionary trajectory, elasmobranch species have not been characterized completely, and still ambiguity persists for some of the species identification. Phylogenetic studies with molecular data would resolve taxonomic ambiguity and provide insights in the evolutionary relationship among elasmobranchs. This chapter summarizes the complete phylogeny work carried on elasmobranchs and highlights the significance of phylogeny for formulating conservation measures.
... Contents were recovered from each gut region of each shark, and total gut content masses ranged from 0.05% to 0.7% of body mass (mean ± SEM: 0.31 ± 0.10%). Because we did not measure body masses of our sharks, we estimated their body masses from the length-weight relationship for scalloped hammerheads (Sphyrna lewini), which are similarly sized and closely related to bonnetheads (Cavalcanti, 2007), using the equations described in Kohler et al. (1996). Frozen samples were then shipped on dry ice to UC Irvine where they were stored at −80°C until analyzed (within 6 months). ...
Few investigations have studied digestive enzyme activities in the alimentary tracts of sharks to gain insight into how these organisms digest their meals. In this study, we examined the activity levels of proteases, carbohydrases, and lipase in the pancreas, and along the anterior intestine, spiral intestine, and colon of the bonnethead shark, Sphyrna tiburo. We then interpreted our data in the context of a rate-yield continuum to discern this shark's digestive strategy. Our data show anticipated decreasing patterns in the activities of pancreatic enzymes moving posteriorly along the gut, but also show mid-spiral intestine peaks in aminopeptidase and lipase activities, which support the spiral intestine as the main site of absorption in bonnetheads. Interestingly, we observed spikes in the activity levels of N-acetyl-β-d-glucosaminidase and β-glucosidase in the bonnethead colon, and these chitin and cellulose, respectively, degrading enzymes are likely of microbial origin in this distal gut region. Taken in the context of intake and relatively long transit times of food through the gut, the colonic spikes in N-acetyl-β-d-glucosaminidase and β-glucosidase activities support the contention that bonnetheads take a yield-maximizing strategy to the digestive process, with some reliance on microbial digestion in their hindguts. This is one of the first studies to examine digestive enzyme activities along the gut of any shark, and importantly, the data match with previous observations that sharks take an extended time to digest their meals (consistent with a yield-maximizing digestive strategy), and that the spiral intestine is the primary site of absorption in sharks.
Copyright © 2015. Published by Elsevier Inc.
... The results are given in Table 2, showing that the optimum of the projection encoding satisfies more quartets of the input data than the MRP supertrees. Finally, the differences of the objective functions of our two encodings can be illustrated by computing the supertree of 5 highly conflicting source trees of 8 species of hammerhead sharks from (Cavalcanti 2007). The optimum for the projection encoding is exactly the same as source tree (b) in (Cavalcanti 2007), whereas the optimum for quartet encoding is exactly the same as source tree (a). ...
... Finally, the differences of the objective functions of our two encodings can be illustrated by computing the supertree of 5 highly conflicting source trees of 8 species of hammerhead sharks from (Cavalcanti 2007). The optimum for the projection encoding is exactly the same as source tree (b) in (Cavalcanti 2007), whereas the optimum for quartet encoding is exactly the same as source tree (a). Thus, the two objective functions are not equivalent in the case of conflicting source trees. ...
The supertree construction problem is about combining several phylogenetic
trees with possibly conflicting information into a single tree that has all the
leaves of the source trees as its leaves and the relationships between the
leaves are as consistent with the source trees as possible. This leads to an
optimization problem that is computationally challenging and typically
heuristic methods, such as matrix representation with parsimony (MRP), are
used. In this paper we consider the use of answer set programming to solve the
supertree construction problem in terms of two alternative encodings. The first
is based on an existing encoding of trees using substructures known as
quartets, while the other novel encoding captures the relationships present in
trees through direct projections. We use these encodings to compute a
genus-level supertree for the family of cats (Felidae). Furthermore, we compare
our results to recent supertrees obtained by the MRP method.
... Most of these hypotheses were based on the analysis of morphological data, with a recent outburst of molecular data [1]. Most of the molecular phylogenies are at the order and family level [2][3][4][5][6][7][8]. Species level phylogenies have included a relatively small number of species [4] and typically focused on smaller clades within sharks such as some families or genera [9][10][11]. ...
The elasmobranchs (sharks, rays and skates) being the extant survivors of one of the earliest offshoots of the vertebrate evolutionary tree are good model organisms to study the primitive vertebrate conditions. They play a significant role in maintaining the ecological balance and have high economic value. Due to over-exploitation and illegal fishing worldwide, the elasmobranch stocks are being decimated at an alarming rate. Appropriate management measures are necessary for restoring depleted elasmobranch stocks. One approach for restoring stocks is implementation of conservation measures and these measures can be formulated effectively by knowing the evolutionary relationship among the elasmobranchs. In this study, a total of 30 species were chosen for molecular phylogeny studies using mitochondrial cytochrome c oxidase subunit I, 12S ribosomal RNA gene and nuclear Internal Transcribed Spacer 2. Among different genes, the combined dataset of COI and 12S rRNA resulted in a well resolved tree topology with significant bootstrap/posterior probabilities values. The results supported the reciprocal monophyly of sharks and batoids. Within Galeomorphii, Heterodontiformes (bullhead sharks) formed as a sister group to Lamniformes (mackerel sharks): Orectolobiformes (carpet sharks) and to Carcharhiniformes (ground sharks). Within batoids, the Myliobatiformes formed a monophyly group while Pristiformes (sawfishes) and Rhinobatiformes (guitar fishes) formed a sister group to all other batoids.
... While interest in the taxonomy of elasmobranchs is probably at an all-time high, efforts to understand their phylogenetic interrelationships have lagged behind (Thomson and Shaffer, 2010). Contributions to our understanding of elasmobranch phylogeny have thus far been restricted to studies focusing on the interrelationships of particular groups, including Arctoraja (Spies et al., 2011), Batoidea (Aschliman et al., in press;McEachran and Aschliman, 2004;Rocco et al., 2007), Carcharhinus (Dosay-Akbulut, 2008), Carcharhinidae (Naylor, 1992), Carcharhiniformes (Compagno, 1988), Dasyatidae (Sezaki et al., 1999), Dasyatis (Rosenberger, 2001), Etmopteridae (Shirai and Nakaya, 1990;Straube et al., 2010), Lamnidae (Dosay-Akbulut, 2007;Martin, 1997), Laminiformes Naylor et al., 1997;Shimada, 2005), Myliobatiformes (de Carvalho et al., 2004;Dunn et al., 2003;Gonzalez-Isáis and Dominguez, 2004;Lovejoy, 1996;Nishida, 1990), Orectolobidae (Corrigan and Beheregaray, 2009), Rajiformes (McEachran and Dunn, 1998;McEachran and Miyake, 1990;Turan, 2008), Scyliorhinidae (Human et al., 2006;Iglésias et al., 2005), Sphyrnidae (Cavalcanti, 2007;Lim et al., 2010), Selachii (Vélez-Zuazo and Agnarsson, 2011), Squatina (Stelbrink et al., 2009), and Triakidae (López et al., 2006), or studies focusing on the relationships among major lineages using a few carefully chosen exemplars for multiple lineages (Compagno, 1977;de Carvalho, 1996;Douady et al., 2003;Heinicke et al., 2009;Maisey, 1984a,b;Mallatt and Winchell, 2007;Naylor et al., 2005;Shirai, 1992Shirai, , 1996Winchell et al., 2004). To our knowledge, no phylogenetic studies of elasmobranchs have incorporated dense taxon sampling at the species level across the entire breadth of elasmobranch diversity. ...
