The mammalian forelimb is adapted to different functions including postural, locomotor, feeding, exploratory, grooming and defence. Comparative studies on morphology of the mammalian scapula have been performed in an attempt to establish the functional differences in the use of the forelimb. In this study, a total of 102 scapulae collected from 66 species of animals, representatives of all major taxa from rodents, sirenians, marsupials, pilosa, cetaceans, carnivores, ungulates, primates and apes, were analysed. Parameters measured included scapular length, width, position, thickness, area, angles and index. Structures included supraspinous and infraspinous fossae, scapular spine, glenoid cavity, acromium and coracoid processes. Images were taken using computed tomographic (CT) scanning technology (CT-Aquarium, Toshiba and micro CT-LaTheta, Hotachi, Japan), and measurement values were acquired and processed using Avizo computer software and CanvasTM 11 ACD systems. Statistical analysis was performed using Microsoft Excel 2013. Results obtained showed that there were differences in morphological characteristics of scapula between mammals with arboreal locomotion and living in forest and mountainous areas and those with leaping and terrestrial locomotion living in open habitat or savannah.Differences were seen in the ratio of maximum length and maximum width, the orientation of scapular spine and the horizontal length of acromion and coracoid processes. The cause for the statistical grouping of the animals and the way the scapular shape covaries with habitat and to the type of locomotion and speed are discussed in detail. K E Y W O R D SCT analysis, mammalian, morphology, scapula
Moles are a strictly fossorial Soricomorpha species and possess a suite of specialized adaptations to subterranean life. However, the contractile function of skeletal muscles in moles remains unclear. We compared muscle fiber‐type distribution in two mole species (the large Japanese mole and lesser Japanese mole) with that in four other Soricomorpha species that are semi‐fossorial, terrestrial, or semi‐aquatic (the Japanese shrew‐mole, house shrew, Japanese white‐toothed shrew, and Japanese water shrew). For a single species, the fiber‐type distribution in up to 38 muscles was assessed using immunohistochemical staining and/or gel electrophoresis. We found that slow and fatigue‐resistant Type I fibers were absent in almost all muscles of all species studied. Although, the two methods of determining the fiber type did not give identical results, they both revealed that fast Type IIb fibers were absent in mole muscles. The fiber‐type distribution was similar among different anatomical regions in the moles. This study demonstrated that the skeletal muscles of moles have a homogenous fiber‐type distribution compared with that in Soricomorpha species that are not strictly fossorial. Mole muscles are composed of Type IIa fibers alone or a combination of Type IIa and relatively fast Type IIx fibers. The homogenous fiber‐type distribution in mole muscles may be an adaptation to structurally simple subterranean environments, where there is no need to support body weight with the limbs, or to move at high speeds to pursue prey or to escape from predators. Anat Rec, 302:1010–1023, 2019. © 2018 Wiley Periodicals, Inc.
ABSTRACT. To clarify the phylogenic relationship of channel catfish with other fishes, the cytochrome b (Cyt b) gene of the catfish was cloned and sequenced. Channel catfish (Ictalurus punctatus) belonging to the family Ictaluridae in the order Siluriformes showed a 78.4-87.4 % similarity to all but one fish of the family Cyprinidae and river loach Crossostoma lacustre of the family Balitoridae in the order Cypriniformes in which genes had already been sequenced, and a 97.2 % similarity to the goldfish (Carassius auratus) belonging to the family Cyprinidae. Within the family Cyprinidae, a 78.8-89.2% similarity to one another was recorded. In addition, the similarity rate between the family Cyprinidae and the family Balitoridae reached a value of 77.8-79.9% in the order Cypriniformes. Furthermore, in an unrooted phylogenetic tree consisting of four branches among eight fishes, channel catfish and goldfish appeared in the same branch. These results suggested that the Cyt b gene of the channel catfish in the order Siluriformes was closely related to that of a goldfish in the order Cypriniformes. The results were not agreement with the morphological classification. Genetic reclassification of the fishes may be necessary to identify the ancestor. This is the first report on the cloning and complete sequencing the Cyt b gene of the channel catfish which may contribute to the genetic reclassification of catfishes belonging to the order Siluriformes. Catfishes with various characteristics are known to consist of about 2,200 species and are widely distributed throughout the world. However, the catfishes have been classified only morphologically. On the other hand, although analyses of mitochondrial genes such as cytochrome b (Cyt b) and 16S ribosomal RNA genes of other fishes have been performed, there has been no report on the analysis of the complete sequences of the genes of the catfishes, unlike those of the genes in other fishes (the family Cyprinidae). Therefore, the evolutionary relationship between the catfishes and others fishes has not been determined. To address this problem, nucleotide sequence analyses of mitochondrial genes have been attempted. As a result, the complete nucleotide sequence of the Cyt b gene of the channel catfish (I. punctatus) were analyzed and the base arrangement between the catfish and other fishes was compared.Total DNAs were isolated from the channel catfish (I. punctatus) [6] and Taq DNA polymerase (Takara-Shuzo Co., Kyoto, Japan). The resultant fragments were introduced into a pUC19 vector and sequenced on both sides by using a DSQ-1000L DNA sequencer (Shimadzu
Turning ability is a factor that determines success in hunting prey and escaping from predators. However, little is understood about the biomechanics of turning at high speeds. We investigated gait characteristics of the cheetah and greyhound while running in a straight line and on curves. Four cheetahs and four greyhounds were filmed running around a 400-m track consisting of two 80-m straights and two bends with a radius of 38 m in a counterclockwise direction. The animals were motivated to run using a lure with speeds of 15-18 m s −1 . We found that the footfall order was fixed during curve running, although it was variable while running straight. Both the cheetahs and greyhounds used the rotatory gallop with the footfall order of right fore, left fore, left hind, and right hind during curve running. The duty factor increased on curves compared with straight running for three out of the four limbs in the greyhounds, but only for the inside hindlimb in the cheetahs. Interlimb coordination varied across running conditions in the cheetahs, but was unchanged in the greyhounds. The results suggest that animals do not use exactly the same strategies to deal with curve running.
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