Ecological adaptations and morphological variation in the posterior disc of larvae of Sciomyzidae (Diptera)

1990 ◽  
Vol 68 (3) ◽  
pp. 517-521 ◽  
Author(s):  
Jean-Claude Vala ◽  
Charles Gasc
Keyword(s):  
Morphological Variation ◽  
Feeding Behaviour ◽  
Posterior Part ◽  
Aquatic Species ◽  
Terrestrial Species ◽  
Ecological Adaptations ◽  
Morphological Aspects

The posterior part of segment 12 in the larvae of Sciomyzidae, commonly called the posterior disc, has four morphological aspects related to habitat and feeding behaviour. According to the variations observed, the following ecological categories can be used: (i) supra-aquatic species have well-developed float hairs (hydrofuge interspiracular processes) and long triangular peripheral lobes of the disc; (ii) semi-aquatic species have moderately developed float hairs and short triangular lobes; (iii) intermediate terrestrial species have very short float hairs and circular lobes; (iv) true terrestrial species have vestigial, scalelike float hairs and hemispherical lobes.

scholarly journals Ontogenetic and inter-elemental osteohistological variability in the leopard tortoise Stigmochelys pardalis

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e8030 ◽  
Author(s):  
Alexander Edward Botha ◽  
Jennifer Botha
Keyword(s):  
Bone Resorption ◽  
Hind Limb ◽  
Life History Traits ◽  
Histological Analysis ◽  
Fundamental System ◽  
Adult Stage ◽  
Aquatic Species ◽  
Terrestrial Species ◽  
Limb Bones ◽  
Hind Limbs

Testudines are a group of reptiles characterized by the presence of a shell covered by keratinous shields. Stigmochelys pardalis is the most widely distributed terrestrial testudine in southern Africa. Although relatively common with some life history traits being well known, the growth of this species has yet to be studied in any detail. The bone microanatomy of this clade differs from that found in other amniotes, where terrestrial species tend to display characteristics normally seen in aquatic species and vice versa. A detailed histological analysis of the limb bones of S. pardalis reveals extensive variation through ontogeny. Cortical bone becomes increasingly thicker through ontogeny and is finally resorbed in the late sub-adult stage, resulting in a thin cortex and a large infilled medullary cavity. The predominant bone tissues are parallel-fibred and lamellar-zonal for the forelimbs and hind limbs respectively. The oldest individual displayed an External Fundamental System indicating that the growth rate had decreased substantially by this stage. Variability is prevalent between the forelimb and hind limb as well as between early and late sub-adults Forelimb elements exhibit characteristics such as faster growing parallel-fibered bone tissue, slightly higher vascularization and a predominance of annuli over Lines of Arrested Growth (LAG) compared to the hind limb which exhibits poorly vascularized, slower growing lamellar-zonal bone interrupted by LAGs. These differences indicate that the forelimb grew more rapidly than the hind limb, possibly due to the method of locomotion seen in terrestrial species. The extensive bone resorption that occurs from the early sub-adult stage destroys much of the primary cortex and results in a significantly different ratio of inner and outer bone diameter (p = 3.59 × 10­−5; df = 28.04) as well as compactness (p = 2.91 × 10­−5; df = 31.27) between early and late sub-adults. The extensive bone resorption seen also destroys the ecological signal and infers an aquatic lifestyle for this species despite it being clearly terrestrial. This supports the results of other studies that have found that using bone microanatomy to determine lifestyle in testudines does not produce accurate results.

scholarly journals Species can base their impression of themselves on the number of sensory neurons they have and their IUCN level

2021 ◽  
Author(s):  
aaron goetz
Keyword(s):  
Emotional Disturbance ◽  
Sensory Neurons ◽  
Killer Whale ◽  
Anthropogenic Influence ◽  
Aquatic Species ◽  
Pilot Whale ◽  
Terrestrial Species ◽  
Western Gorilla ◽  
Pilot Whales

Abstract Humans have the most sensory neurons of any terrestrial species, 18.83B, with more than twice as many as the runner up western gorilla. There are three aquatic species with more than humans and seven more with more than the western gorilla. The killer whale with more than twice as many as humans, long-finned and short-finned pilot whale with a little less than twice humans. With that many sensory neurons it would be assumed that those would be the species with the most emotional disturbance from anthropogenic influence. There is no data on killer whale endangerment, and both long and short finned pilot whales are LC, ranking them 23rd and 24th most disturbed species. It is important for us to consider what the species means to them in evaluating what species we should care about, it would be beneficial to base that on what species care about themselves the most.

scholarly journals Comparative morphology of the seminal receptacles of Ocypode quadrata (Fabricius, 1787) (Brachyura, Ocypodoidea)

Zootaxa ◽  
2009 ◽  
Vol 2106 (1) ◽  
pp. 41-50 ◽  
Author(s):  
LAURA S. LÓPEZ-GRECO ◽  
VÍVIAN FRANSOZO ◽  
MARIA LUCIA NEGREIROS-FRANSOZO ◽  
DANIELA CARVALHO DOS SANTOS
Keyword(s):  
Mating System ◽  
Comparative Morphology ◽  
Aquatic Species ◽  
Terrestrial Species ◽  
Ocypode Quadrata ◽  
Cuticular Layer

The seminal receptacles of the Eubrachyura are an ecto-mesodermic differentiation of the genital ducts where the spermatophores are stored and fertilization takes place. The position in which the oviduct is connected to the seminal receptacles varies among species and two types, dorsal and ventral, can be distinguished. The dorsal type is frequently observed in the “soft mating system” species, while the ventral one is usually related to the “hard mating system” species. The seminal receptacles (SR) of Ocypode quadrata (Fabricius, 1787) are paired, spherical and opalescent structures with a ventral connection to the oviduct and without any differences between the two members of the pair. The SR present macroscopic features that resemble other semi-terrestrial species of Ocypodoidea and Grapsoidea, but some histological characters resemble more aquatic species such as the Majoidea. The mesodermic portion of the SR is delimited by a cubic-flat secretor epithelium with three layers of muscular cells and surrounded externally by a simple capsule of conjunctive tissue. The transition between the mesodermic and the ectodermic areas is abrupt and characterized by a folded epithelium resembling that described for some Majoidea and the presence of a high cuticular layer. Only free spermatozoa were found, but no differentiated spermatophore packages or spermatophores.

scholarly journals Integrated terrestrial-freshwater planning doubles conservation of tropical aquatic species

Science ◽  
2020 ◽  
Vol 370 (6512) ◽  
pp. 117-121 ◽  
Author(s):  
Cecília G. Leal ◽  
Gareth D. Lennox ◽  
Silvio F. B. Ferraz ◽  
Joice Ferreira ◽  
Toby A. Gardner ◽  
...  
Keyword(s):  
Freshwater Species ◽  
Aquatic Species ◽  
Freshwater Biodiversity ◽  
Biodiversity Data ◽  
Terrestrial Species ◽  
Aquatic Connectivity ◽  
The Status ◽  
Conservation Actions ◽  
Terrestrial Biodiversity

Conservation initiatives overwhelmingly focus on terrestrial biodiversity, and little is known about the freshwater cobenefits of terrestrial conservation actions. We sampled more than 1500 terrestrial and freshwater species in the Amazon and simulated conservation for species from both realms. Prioritizations based on terrestrial species yielded on average just 22% of the freshwater benefits achieved through freshwater-focused conservation. However, by using integrated cross-realm planning, freshwater benefits could be increased by up to 600% for a 1% reduction in terrestrial benefits. Where freshwater biodiversity data are unavailable but aquatic connectivity is accounted for, freshwater benefits could still be doubled for negligible losses of terrestrial coverage. Conservation actions are urgently needed to improve the status of freshwater species globally. Our results suggest that such gains can be achieved without compromising terrestrial conservation goals.

scholarly journals Carapacial scute anomalies of star tortoise (Geochelone elegans) in Western India

2012 ◽  
Vol 4 (2) ◽  
pp. 105-107
Author(s):  
Raju Vyas
Keyword(s):  
Developmental Instability ◽  
Western India ◽  
Aquatic Species ◽  
Standard Pattern ◽  
Terrestrial Species ◽  
Normal Number ◽  
Reptile Species ◽  
Geochelone Elegans

The basic taxonomy and classification of reptile species and genera often use pholidotic characters. Despite that each species has a standard pattern, there are always deviant individuals in terms of scale number, shape, size, or color. Turtles are excellent models for the study of developmental instability because anomalies are easily detected in the form of malformations, additions, or reductions in the number of scutes or scales. The normal number of carapacial scutes in turtles is five vertebrals, four pairs of costals, and 12 pairs of marginals, a pattern known as “typical chelonian carapacial scutation”. Any deviation of vertebral, costal, or marginal scute numbers or their pattern represents an anomaly. Zangerl & Johnson (1957) documented scutation anomalies in 118 species of turtles belonging to seven families, with higher levels of carapace anomalies in aquatic species compared to semi-aquatic and terrestrial species.

scholarly journals Seasonal body size reductions with warming covary with major body size gradients in arthropod species

2017 ◽  
Vol 284 (1851) ◽  
pp. 20170238 ◽  
Author(s):  
Curtis R. Horne ◽  
Andrew G. Hirst ◽  
David Atkinson
Keyword(s):  
Body Size ◽  
Size Variation ◽  
Seasonal Temperature ◽  
Adult Size ◽  
Aquatic Species ◽  
Terrestrial Species ◽  
Total Percentage ◽  
Arthropod Species ◽  
Seasonal Temperature Variation ◽  
Developmental Conditions

Major biological and biogeographical rules link body size variation with latitude or environmental temperature, and these rules are often studied in isolation. Within multivoltine species, seasonal temperature variation can cause substantial changes in adult body size, as subsequent generations experience different developmental conditions. Yet, unlike other size patterns, these common seasonal temperature–size gradients have never been collectively analysed. We undertake the largest analysis to date of seasonal temperature-size gradients in multivoltine arthropods, including 102 aquatic and terrestrial species from 71 global locations. Adult size declines in warmer seasons in 86% of the species examined. Aquatic species show approximately 2.5-fold greater reduction in size per °C of warming than terrestrial species, supporting the hypothesis that greater oxygen limitation in water than in air forces aquatic species to exhibit greater plasticity in body size with temperature. Total percentage change in size over the annual cycle appears relatively constant with annual temperature range but varies between environments, such that the overall size reduction in aquatic-developing species (approx. 31%) is almost threefold greater than in terrestrial species (approx. 11%). For the first time, we show that strong correlations exist between seasonal temperature–size gradients, laboratory responses and latitudinal–size clines, suggesting that these patterns share common drivers.

Variation of hyoid morphology in geoemydid terrapins

2007 ◽  
Vol 28 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Markus Auer ◽  
Uwe Fritz ◽  
Susann Richter
Keyword(s):  
Ontogenetic Development ◽  
Aquatic Species ◽  
Terrestrial Species ◽  
Positive Correlation ◽  
Mode Of Life

AbstractThe hyoid apparati of 25 geoemydid species in 16 genera (including aquatic, semiterrestrial and terrestrial taxa) are compared, and for Cuora galbinifrons bourreti ontogenetic development of the hypoid apparatus is described. Generally, ossification of the hyoid apparatus increases with age. The majority of terrestrial species maintain cartilaginous or partially cartilaginous hyoid bodies and second branchial horns throughout life however. Also in tortoises (Testudinidae) hyoid body and second branchial horns remain cartilaginous, suggesting a positive correlation between mode of life and hyoid morphology (terrestrial species with partly cartilaginous hyoid apparatus vs. aquatic species with fully ossified hyoid apparatus).

scholarly journals LOS MAMIFEROS DE OAXACA

2015 ◽  
Vol 4 (2) ◽  
pp. 18 ◽  
Author(s):  
Antonio Santos Moreno
Keyword(s):  
Species Richness ◽  
The State ◽  
Risk Category ◽  
Aquatic Species ◽  
Wild Mammal ◽  
Additional Species ◽  
Terrestrial Species ◽  
Molecular Differentiation ◽  
Mammal Fauna ◽  
Very High

RESUMENLa fauna de mamíferos silvestres del estado de Oaxaca está constituida por 222 especies, que representan 131 géneros, 34 familias y 12 ordenes. 93 especies son murciélagos, 13 acuáticas y 116 terrestres no voladoras. 45 especies endémicas de México están presentes en Oaxaca, y de estas, 14 son exclusivas del Estado. 69 especies con presencia en Oaxaca se encuentran incluidas en alguna categoría de riesgo de acuerdo a las leyes mexicanas, mientras que 28 especies están incluidas en alguna de las categorías de la CITES y 38 en las de la IUCN. Aunque el número de especies con presencia confirmada en el estado es muy alto, es muy probable que se incremente próximamente, pues existen aún áreas considerables sin explorar en la entidad; poblaciones de varias especies montanas muestran alta diferenciación genética y molecular; así mismo, varios estudios demuestran la presencia de especies adicionales a las ya registradas en regiones cercanas al territorio oaxaqueño.Palabras clave: Diversidad, distribución, endemismo, mastozoología, riqueza de especies.ABSTRACTThe wild mammal fauna of the state of Oaxaca consists of 222 species, representing 131 genera, 34 families, and 12 orders. 93 species are bats, 13 are aquatic species, and 116 non-flying terrestrial species. 45 species endemic to Mexico are present in Oaxaca, and of these, 14 are unique to the State. 69 species present in Oaxaca are included in any risk category according to Mexican laws, while 28 species are included in a category of CITES and 38 in IUCN. Although the number of species with confirmed presence in the state is very high, it is very likely to increase soon, as there are still considerable unexplored areas in the state; montane populations of several species show high genetic and molecular differentiation molecular; and several studies show the presence of additional species have already been registered in regions near the Oaxaca´s territory.Key words: Diversity, distribution, endemismo, mammalogy, species richness.

scholarly journals Convergent evolution of skin surface microarchitecture and increased skin hydrophobicity in semi-aquatic anole lizards

2021 ◽  
Vol 224 (19) ◽  
Author(s):  
Simon Baeckens ◽  
Marie Temmerman ◽  
Stanislav N. Gorb ◽  
Chiara Neto ◽  
Martin J. Whiting ◽  
...  
Keyword(s):  
Convergent Evolution ◽  
Aquatic Invertebrates ◽  
Complex Surface ◽  
Skin Surface ◽  
Water Repellent ◽  
Aquatic Species ◽  
Ecological Significance ◽  
Terrestrial Species ◽  
Exciting Line ◽  
Surface Microstructures

ABSTRACT Animals that habitually cross the boundary between water and land face specific challenges with respect to locomotion, respiration, insulation, fouling and waterproofing. Many semi-aquatic invertebrates and plants have developed complex surface microstructures with water-repellent properties to overcome these problems, but equivalent adaptations of the skin have not been reported for vertebrates that encounter similar environmental challenges. Here, we document the first evidence of evolutionary convergence of hydrophobic structured skin in a group of semi-aquatic tetrapods. We show that the skin surface of semi-aquatic species of Anolis lizards is characterized by a more elaborate microstructural architecture (i.e. longer spines and spinules) and a lower wettability relative to closely related terrestrial species. In addition, phylogenetic comparative models reveal repeated independent evolution of enhanced skin hydrophobicity associated with the transition to a semi-aquatic lifestyle, providing evidence of adaptation. Our findings invite a new and exciting line of inquiry into the ecological significance, evolutionary origin and developmental basis of hydrophobic skin surfaces in semi-aquatic lizards, which is essential for understanding why and how the observed skin adaptations evolved in some and not other semi-aquatic tetrapod lineages.

scholarly journals The heart rate - breathing rate relationship in aquatic mammals: A comparative analysis with terrestrial species

2015 ◽  
Vol 61 (4) ◽  
pp. 569-577 ◽  
Author(s):  
Jacopo P. Mortola
Keyword(s):  
Heart Rate ◽  
Body Size ◽  
Water Surface ◽  
Low Frequency ◽  
Breath Holding ◽  
Aquatic Species ◽  
Terrestrial Species ◽  
Terrestrial Mammals ◽  
The Difference ◽  
Aquatic Mammals

Abstract Aquatic and semi-aquatic mammals, while resting at the water surface or ashore, breathe with a low frequency (f) by comparison to terrestrial mammals of the same body size, the difference increasing the larger the species. Among various interpretations, it was suggested that the low-f breathing is a consequence of the end-inspiratory breath-holding pattern adopted by aquatic mammals to favour buoyancy at the water surface, and evolved to be part of the genetic makeup. If this interpretation was correct it could be expected that, differently from f, the heart rate (HR, beats/min) of aquatic and semi-aquatic mammals at rest would not need to differ from that of terrestrial mammals and that their HR-f ratio would be higher than in terrestrial species. Literature data for HR (beats/min) in mammals at rest were gathered for 56 terrestrial and 27 aquatic species. In aquatic mammals the allometric curve (HR=191·M-0.18; M= body mass, kg) did not differ from that of terrestrial species (HR=212·M-0.22) and their HR-f ratio (on average 32±5) was much higher than in terrestrial species (5±1) (P<0.0001). The comparison of these HR allometric curves to those for f previously published indicated that the HR-f ratio was body size-independent in terrestrial species while it increased significantly with M in aquatic species. The similarity in HR and differences in f between aquatic and terrestrial mammals agree with the possibility that the low f of aquatic and semi-aquatic mammals may have evolved for a non-respiratory function, namely the regulation of buoyancy at the water surface.

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