Body weight: its relation to tissue composition, segment distribution, and motor function. I. Interspecific comparisons.

The composition of skin, muscle, and bone and their distribution throughout the body are compared for "advanced" or "specialized" species (Alouatta, Macaca, Canis, Felis, Lepus); smaller, more closely related species (Tupaia and the Lorisidae); and several species within the same ecosystem (Barro Colorado Island, Panama). Among the most significant variables, the skin of sloths, howlers and macaques constitutes more than 12% of body weight, whereas greyhound skin is 5% of weight; sloth and howler muscle are 25% of weight, macaque muscle about 40% of weight, greyhound and agouti muscle over 50% of weight. In tree shrews and galagos muscle is heavier (35%) than in pottos and slow lorises (below 28%), but bone and skin are lighter. All species differ in the segmental distribution of weight. Cats have light tails, light feet and heavy thighs, whereas howlers have heavy tails, heavy feet, and light thighs. The galagos have heavy hindlimbs and tails, the pottos and lorises have reduced tails and approximately equal fore- and hindlimbs. Convergences in segment pattern (sloths with pottos and lorises, marmosets with tree shrews, owl monkeys with galagos, cebus with macaques) as well as divergences are documented. All weight-of tissue and weight-of-segment variables are correlated directly with locomotor adaptation.     

The function and phylogenetic implications of the tentorium in adult Neuroptera (Insecta)

Despite several recent analyses on the phylogeny of Neuroptera some questions still remain to be answered. In the present analysis we address these questions by exploring a hitherto unexplored character complex: the tentorium, the internal cuticular support structure of the insect head. We described in detail the tentoria of representatives of all extant neuropteran families and the muscles originating on the tentorium using 3D microCT images and analyzed differences in combination with a large published matrix based on larval characters. We find that the tentorium and associated musculature are a source of phylogenetically informative characters. The addition of the tentorial characters to the larval matrix causes a basad shift of the Sisyridae and clearly supports a clade of all Neuroptera except Sisyridae and Nevrorthidae. A sister group relationship of Coniopterygidae and the dilarid clade is further corroborated. A general trend toward a reduction of the dorsal tentorial arms and the development of laminatentoria is observed. In addition to the phylogenetic analysis, a correlation among the feeding habits, the development of the maxillary muscles, and the laminatentoria is demonstrated.     

Resolving insect phylogeny: The significance of cephalic structures of the Nannomecoptera in understanding endopterygote relationships

The Nannomecoptera are among the most enigmatic and controversial taxa of endopterygote insects, the phylogenetic resolution of which is crucial to understanding the evolution of neopteran insects. Once considered a subordinate lineage within the Mecoptera, renewed interest in nannochoristids has been prompted by evidence that the Nannomecoptera are not admissible to the clade of extant scorpion flies but are more likely to belong to the clade Siphonaptera + Nannomecoptera + Diptera. The overarching purpose of the present account is to provide novel and extensive morphological character traits in addition to those already existing for adult structures. The aim is to determine if these traits support molecular data sets that have been suggested elsewhere to clarify the phyletic position of Nannochoristidae. This account focuses on nannomecopteran larvae, which unlike those of other mecopterans have received little attention. Thus, the thrust of this investigation is to provide detailed anatomical data on nannochoristid larvae for a targeted inquiry into their phylogenetic affinities. The described characters are discussed and presented in a data matrix comprising representatives of all endopterygote orders. While the study is based primarily on the New Zealand species Nannochorista philpotti, it is proposed that all nannomecopteran larvae will prove to be similar to this taxon in most if not all structural features of significance to a higher-level phylogenetic context.     

The male genitalia of Oxyartes lamellatus - phasmatodeans do have complex phallic organs (Insecta: Phasmatodea)

A detailed study of the exoskeleton and musculature of the phallic organ of Oxyartes lamellatus (Kirby, 1904) (Phasmatodea: Necrosciinae) is here presented - the first study of this kind for Phasmatodea. The asymmetrical phallic organ shows a highly complicated morphology, with several sclerites and many formative structural elements, of which a sclerotised bulb in the ejaculatory duct wall and a long flagellum arising from near it are among the most conspicuous. Four extrinsic and 20 intrinsic phallic muscles were found; many of these are quite compact bundles or sheets, while a few others are diffuse groups of fibres. Phallic morphology in Oxyartes is compared with the literature data on male genitalia in other Phasmatodea, but this is limited by the superficial treatment of phallic organs in the few relevant previous contributions. Yet, phallic organs appear as a useful new character system for phylogenetic reconstruction and species distinction in Phasmatodea. Comparison with phallic organs in other ‘orthopteroid’ insects shows that these organs are too different among orders as to allow for sound homologisation of phallic substructures. Consideration of development of phallic organs does not help in this aspect. There is no evidence of phasmatodean phallic organs being pedomorphic.     

An analysis of the muscular limitation on opposability in seven species of Cercopithecinae

Cercopithecinae have long been considered to have a manus capable of opposition. Observations of manipulation in seven quadrupedal species of Cercopithecinae show that three opposable grips are used, ranging from the ultimate refinement of the “precision grip,” the refined opposition, where contact is made between the distal pads of the first digit (d1) and the second digit (d2), to the cup, where the pollex is equidistant from, and presses an object against, the palmar pads of the other digits. The most frequently used hand position was the quasi-opposition, where the distal pad of d1 contacts d2 anywhere along its lateral aspect. Dissections of the muscles of the pollex showed that in all the species studied refined opposition depends on the abductor brevis and opponens pollicis. In general the other pollical muscles, which enhance opposition in man, are limiting factors on this movement. The differences among the species, however, tend to reflect use of the hand. Thus, those species subsisting principally on a diet of seeds and grasses were found to have the highest frequency of refined opposition, and their pollical anatomy shows a muscular configuration facilitating opposition. The suggestion is made that manipulation as in procuring, conveying and preparing food may have been a more important adaptive pressure than locomotion in retention of the generalized form of the cercopithecine hand.     

The somatic musculature of Bryceella stylata (Milne, 1886) (Rotifera: Proalidae) as revealed by confocal laser scanning microscopy with additional new data on its trophi and overall morphology

The monogonont rotifer Bryceella stylata was investigated with light, electron and confocal laser scanning (CLSM) microscopy to provide detailed insights into its anatomy and new information for future phylogenetic analyses of the group. Results from CLSM and phalloidin staining revealed a total of six paired longitudinal muscles (musculi longitudinales I-VI) and eight circular muscles (musculi circulares I-VIII) as well a complex network of mostly fine visceral muscles. In comparison with other rotifer species that have been investigated so far, B. stylata shares the presence of the circular and longitudinal muscles: musculus longitudinalis ventralis, musculus longitudinalis lateralis inferior, musculus longitudinalis dorsalis, musculus longitudinalis capitis and musculus circumpedalis. However, the species lacks lateral and dorsolateral longitudinal muscles and some circular muscles (e.g., corona sphincter, musculus pars coronalis). With light and electron microscopy, we were able to document the precise number of pseudosegments and the arrangement of the chambers comprising the trophi elements. Furthermore, our observations revealed several new morphological characteristics, including a shield-like epidermal projection covering the dorsal antenna, an epidermal projection restricting the corona caudally and an unpaired hypopharynx with distinct shovel-like structures.     

The musculature of horsehair worm larvae (<Emphasis Type="Italic">Gordius aquaticus</Emphasis>,<Emphasis Type="Italic"> Paragordius varius</Emphasis>, Nematomorpha): F-actin staining and reconstruction by cLSM and TEM

The musculature of larvae of Gordius aquaticus was investigated by laser-scanning microscopy and compared to transmission electron microscopic data for the larva of Paragordius varius. In the anterior portion of the body, the preseptum, four different muscle groups can be distinguished: (1) 12 anterior parietal muscles in the body wall, (2) six oblique muscles that function as retractors of the introvert, (3) six proboscideal muscles, which function as retractors for the proboscis, and (4) six muscles associated with spines of the outermost of the three rings of spines. The posterior portion of the body, the postseptum, possesses four pairs of longitudinal muscle strands in G. aquaticus, the postseptal parietal muscles, that are located dorsolaterally and ventrolaterally. These are not clearly visible in P. varius, where instead three pairs of parietal muscles are present. Additional small muscles are associated with the terminal spines and with the duct running from the pseudointestine to the body wall. All fibers show a cross-striated pattern although this striation is less obvious at the ends of the fibers.     

Molecular identification of pufferfish species using PCR amplification and restriction analysis of a segment of the 16S rRNA gene

This study amplified the mitochondrial 16S rRNA gene using polymerase chain reaction (PCR) with a template of total DNA from muscle tissues of nine pufferfish species collected from the coastal area of Okinawa Islands in Japan: Pleuranacanthus sceleratus, Triodon macropterus, Chelonodon patoca, Sphoeroides pachygaster, Arothron hispidus, A. stellatus, A. manilensis, A. mappa, and A. nigropunctatus. Then nucleotide sequence encoding a partial region of the 16S rRNA gene was compared among species. The sequenced fragment was also used to select restriction enzymes, yielding species-specific restriction fragment length polymorphisms (RFLP). The sequence of the segment of the 16S rRNA gene consisted of about 615 nucleotides and showed interspecies variations in the targeted region. After calculation of corresponding RFLP-patterns of nine species investigated with suitable restriction enzymes, three restriction enzymes – BanII, DdeI, and NlaIII – were found to be sufficient for identification of all nine species. Successful testing of this methodology in frozen and heated food samples suggests its utility for pufferfish species authentication in food products.     

Body weight: its relation to tissue composition, segment distribution, and motor function. II. Development of Macaca mulatta.

The relative composition of skin, muscle, and bone and their distribution patterns throughout the body are given for a series of Macaca mulatta from 171 days conceptual age through adulthood. In terms of percent of total body weight, the musculature of these animals doubles during the firs postnatal year whereas bone and skin decrease. Regionally, the muscles of the thighs, back extensors, truncal-forelimb and upper arms increase most markedly. The thighs double and the upper arms increase whereas the trunk, hands, feet, and tail decrease. The biomechanical implications of these changes for motor development are discussed.