Description of the statolith shape of two sympatric ommastrephids in the Mexican Pacific obtained from geometric morphometrics as a tool for identification at the species level

One of the main challenges in the conservation of biodiversity is to overcome inadequate knowledge about species and their intra-specific diversity. In the present study, we attempted to assess morphological distinction of the two previously identified genetic clades within the Luristan newt (Neurergus kaiseri, Schmidt 1952) endemic to Iran, which is essential for its conservation planning. Signals of the morphological variation in N. kaiseri were evaluated using landmark-based geometric morphometrics of body shape and characters of osteological structures. Morphological approaches revealed consistent groupings within the species, confirming the presence of two distinct lineages (previously named as the northern and southern clades). The morphological and genetic data provide evidence for the possible co-existence of two species in N. kaiseri and we recommend assigning the newly recognised forms to the species level.

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Unexpected Morphological Diversity in New Zealand’s Large Diplodactylidae Geckos

10.21203/rs.3.rs-209257/v1 ◽

2021 ◽

Author(s):

Lachie Scarsbrook ◽

Emma Sherratt ◽

Rod Hitchmough ◽

R. Ewan Fordyce ◽

Nicolas J. Rawlence

Keyword(s):

New Zealand ◽

Geometric Morphometrics ◽

Relative Size ◽

Three Dimensional ◽

Morphological Diversity ◽

Anthropogenic Disturbances ◽

Species Level ◽

Global Biodiversity ◽

The Impact ◽

Shape And Size

Abstract Prehistoric anthropogenically-mediated extinctions have impacted global biodiversity; however effects on herpetofauna are poorly-documented. New Zealand’s Diplodactylidae geckos exhibit high species-level diversity, largely independent of discernible osteological changes (cryptic). Consequently, taxonomic affinities of isolated skeletal elements (fossils) are primarily determined by relative size, particularly in the identification of Hoplodactylus duvaucelii; New Zealand’s largest extant gecko species. Here, three-dimensional geometric morphometrics of maxillae (a common fossilized element) was used to determine whether consistent shape and size differences exist between genera, and if cryptic extinctions have occurred in ‘Hoplodactylus cf. duvaucelii’. Sampling included 13 Diplodactylidae species from five genera, and 11 Holocene ‘H. cf. duvaucelii’ subfossil individuals. We found phylogenetic history was the most important predictor of maxilla morphology among extant Diplodactylidae genera. Relative size comparisons could only differentiate Hoplodactylus from other genera, with the remaining genera exhibiting variable degrees of overlap. Six subfossils were positively identified as H. duvaucelii, confirming their proposed Holocene distribution throughout New Zealand. Conversely, five subfossils showed no affinities towards any modern Diplodactylidae genera, implying either increased morphological diversity in mainland ‘H. cf. duvaucelii’ or the presence of at least one extinct, large, broad-toed Diplodactylidae species. These results highlight the impact of anthropogenic disturbances on insular reptile diversity.

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Australian rodents reveal conserved Cranial Evolutionary Allometry across 10 million years of murid evolution

10.1101/2020.04.30.071308 ◽

2020 ◽

Cited By ~ 2

Author(s):

Ariel E. Marcy ◽

Thomas Guillerme ◽

Emma Sherratt ◽

Kevin C. Rowe ◽

Matthew J. Phillips ◽

...

Keyword(s):

Body Size ◽

Geometric Morphometrics ◽

Species Level ◽

Stabilizing Selection ◽

Ecological Opportunity ◽

Masticatory Efficiency ◽

Evolutionary Allometry ◽

Murid Rodents ◽

Masticatory Apparatus

ABSTRACTAmong vertebrates, placental mammals are particularly variable in the covariance between their cranial shapes and body size (allometry), with the notable exception of rodents. Australian murid rodents present an opportunity to assess the cause of this anomaly because they radiated on an ecologically diverse continent unique for lacking other terrestrial placentals. Here we used 3D geometric morphometrics to quantify species-level and evolutionary allometries in 38 species (317 crania) from all Australian murid genera. We ask if ecological opportunity resulted in greater allometric diversity; conversely, we test if intrinsic constraints and/or stabilizing selection conserved allometry. To increase confidence in species-level allometric slopes, we introduce a new phylogeny-based method of bootstrapping and randomly resampling across the whole sample. We found exceedingly conserved allometry across the 10 million year split between Mus and the clade containing Australian murids. Cranial shapes followed craniofacial evolutionary allometry (CREA) patterns, with larger species having relatively longer snouts and smaller braincases. CREA is consistent with both intrinsic constraints and stabilizing selection hypotheses for conserved allometry. However, large-bodied frugivores evolved faster, while carnivorous specialists showed skull modifications known to conflict with masticatory efficiency. These results suggest a strong role of stabilizing selection on the masticatory apparatus of murid rodents.

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Molecular Phylogenetics of Trapezia Crabs in the Central Mexican Pacific

Oceans ◽

10.3390/oceans1030011 ◽

2020 ◽

Vol 1 (3) ◽

pp. 156-164

Author(s):

Hazel M. Canizales-Flores ◽

Alma P. Rodríguez-Troncoso ◽

Eric Bautista-Guerrero ◽

Amílcar L. Cupul-Magaña

Keyword(s):

Molecular Phylogenetics ◽

Coral Species ◽

Nuclear Gene ◽

Integrative Taxonomy ◽

Species Level ◽

Crab Species ◽

Tropical Eastern Pacific ◽

Mexican Pacific ◽

Molecular Analyses ◽

Coral Communities

To date, Trapezia spp. crabs have been considered obligate symbionts of pocilloporid corals. They protect their coral hosts from predators and are essential for the health of certain coral species. However, the basic details of this group of crustaceans are lacking, and there is a need for species-level molecular markers. The Tropical Eastern Pacific (TEP) region harbors important coral communities mainly built by corals of the genus Pocillopora, with three known Trapezia species known to associate with them: Trapezia bidentata, T. formosa and T. corallina. Both taxonomic and molecular analyses were carried out with samples of all three crab species collected from Pocillopora spp. in the Central Mexican Pacific. Analysis of both a mitochondrial and a nuclear gene revealed only two species, T. corallina and T. bidentata. T. formosa however appears to be a morphotype of T. bidentata. The use of integrative taxonomy for this group has increased the knowledge of the biodiversity not only of the study area, but of the whole TEP and will enhance the future study of the Trapezia–Pocillopora symbiosis.

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Comparison of Landmark- and Outline-Based Geometric Morphometrics for Discriminating Mosquito Vectors in Ratchaburi Province, Thailand

BioMed Research International ◽

10.1155/2018/6170502 ◽

2018 ◽

Vol 2018 ◽

pp. 1-10 ◽

Cited By ~ 2

Author(s):

Tanawat Chaiphongpachara

Keyword(s):

Aedes Aegypti ◽

Geometric Morphometrics ◽

Culex Quinquefasciatus ◽

Low Cost ◽

Species Level ◽

Malaria Vectors ◽

Mosquito Vectors ◽

Successful Control ◽

Dengue Vectors ◽

Anopheles Barbirostris

It is often challenging to identify mosquito vectors in the field based on morphological features due to their similar morphologies and difficulties in obtaining undamaged samples but is required for their successful control. Geometric morphometrics (GM) overcomes this issue by analyzing a suite of traits simultaneously and has the added advantages of being easy to use, low cost, and quick. Therefore, this research compared the efficiency and precision of landmark- and outline-based GM techniques for separating species of mosquitoes in Huay Nam Nak village, Ratchaburi Province, Thailand. This research collected 273 individuals belonging to seven species: Anopheles barbirostris, An. subpictus, Culex quinquefasciatus, Cx. vishnui, Cx. whitmorei, Aedes aegypti, and Ae. albopictus. Both landmark-based and outline-based GM techniques could identify malaria vectors in this area to the genus level successfully and were also very effective for identifying the malaria vectors Anopheles spp. and the dengue vectors Aedes spp. to the species level. However, they were less effective for distinguishing between species of Culex. Therefore, GM represents a valuable tool for the identification of mosquito vectors in the field, which will facilitate their successful control.

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Shell shape as an indicator of phenotypic stocks of Tehuelche scallop (Aequipecten tehuelchus) in Northern Patagonia, Argentina

10.1101/2021.10.14.464278 ◽

2021 ◽

Author(s):

Leandro Nicolas Getino Mamet ◽

Gaspar Soria ◽

Laura Schejter ◽

Federico Marquez

Keyword(s):

Genetic Differentiation ◽

Geometric Morphometrics ◽

Fishery Management ◽

Species Level ◽

Shell Shape ◽

Shape Variation ◽

Geographic Scale ◽

Northern Patagonia ◽

Morphologic Variation ◽

Genetic Pool

Tehuelche scallop, Aequipecten tehuelchus, is a commercially exploited species in Northern Patagonia, Argentina. Without genetic differentiation at the species level, A. tehuelchus presents three morphotypes: tehuelchus, madrynensis, and a non-common variant felipponei. The main goal of this study was to analyze the shell shape variation of Tehuelche scallop to differentiate and identify the phenotypic stocks. The shape differences between and within the two main morphotypes (tehuelchus and madrynensis) were assessed using geometric morphometrics in nine localities. The shell shape presented variability at geographic scale, with the morphologic traits that maximized the differentiation among localities between the tehuelchus and madrynensis morphotypes. Scallops from madrynensis morphotype presented higher and circular shell discs with smaller auricles than those from tehuelchus morphotype. Morphometric differentiation was also detected among localities of each morphotype, wherein most of the variability was related to the disc circularity and the symmetry of the auricles. The presence of morphologic variation in San Matias and San Josi gulfs, wherein a single genetic pool is shared, evidenced the plastic nature of the species. Given the distribution of this resource in distinct provincial jurisdictions, the differentiation of phenotypic stocks has relevance in the context of fishery management, especially if zoning and rotational strategies are implemented.

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Mapping mangrove leaf area index at the species level using IKONOS and LAI-2000 sensors for the Agua Brava Lagoon, Mexican Pacific

Estuarine Coastal and Shelf Science ◽

10.1016/j.ecss.2004.09.027 ◽

2005 ◽

Vol 62 (1-2) ◽

pp. 377-384 ◽

Cited By ~ 75

Author(s):

John M. Kovacs ◽

Jinfei Wang ◽

Francisco Flores-Verdugo

Keyword(s):

Leaf Area Index ◽

Leaf Area ◽

Species Level ◽

Area Index ◽

Mexican Pacific

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Skeletal variation in extant species enables systematic identification of New Zealand’s large, subfossil diplodactylids

BMC Ecology and Evolution ◽

10.1186/s12862-021-01808-7 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Lachie Scarsbrook ◽

Emma Sherratt ◽

Rodney A. Hitchmough ◽

Nicolas J. Rawlence

Keyword(s):

New Zealand ◽

Geometric Morphometrics ◽

Three Dimensional ◽

Morphological Diversity ◽

Species Level ◽

Important Predictor ◽

Extant Species ◽

Systematic Identification ◽

Shape And Size

AbstractNew Zealand’s diplodactylid geckos exhibit high species-level diversity, largely independent of discernible osteological changes. Consequently, systematic affinities of isolated skeletal elements (fossils) are primarily determined by comparisons of size, particularly in the identification of Hoplodactylus duvaucelii, New Zealand’s largest extant gecko species. Here, three-dimensional geometric morphometrics of maxillae (a common fossilized element) was used to determine whether consistent shape and size differences exist between genera, and if cryptic extinctions have occurred in subfossil ‘Hoplodactylus cf. duvaucelii’. Sampling included 13 diplodactylid species from five genera, and 11 Holocene subfossil ‘H. cf. duvaucelii’ individuals. We found phylogenetic history was the most important predictor of maxilla morphology among extant diplodactylid genera. Size comparisons could only differentiate Hoplodactylus from other genera, with the remaining genera exhibiting variable degrees of overlap. Six subfossils were positively identified as H. duvaucelii, confirming their proposed Holocene distribution throughout New Zealand. Conversely, five subfossils showed no clear affinities with any modern diplodactylid genera, implying either increased morphological diversity in mainland ‘H. cf. duvaucelii’ or the presence of at least one extinct, large, broad-toed diplodactylid species.

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