Surface ultrastructure of the adult and juvenile stages of the trematode Astiotrema impletum (Looss, 1899) Looss 1900 (incertae sedis) from the Nile puffer, Tetraodon lineatus Linnaeus, 1758

Summary A scanning electron microscope study was performed on the surface of the trematode Astiotrema impletum (Looss, 1899) Looss 1900 from the Nile puffer, Tetraodon lineatus Linnaeus, 1758 (Syn. Tetraodon fahaka) for the first time. Adult A. impletum have a markedly large, sub-terminal oral sucker and a small ventral sucker. As with most trematodes, tegumental spines are concentrated anteriorly and are absent just anterior the ventral sucker. Spines have serrated tips on a short, tongue–shaped body. At the level of the ventral sucker the base of each spine exhibits a three bulbous-like structure that can be partially or completely withdrawn into the tegument. Sensory papillae are concentrated around the oral and ventral suckers and genital pores. Papillae are conical or knob-like, either ciliated or non-ciliated; some are protruded and others are embedded inside the tegument. In the juvenile stage, spines are smaller, less well-developed and tightly packed. The cytoplasmic processes of the posterior quarter of body show brain-like velvety appearance on the adult and small cobblestone-like on the juvenile.

Didogobius janetarum sp. nov., a new cryptobenthic goby species from the Cape Verde Islands (Teleostei: Gobiidae)

Didogobius janetarum sp. nov. is described from five specimens collected from small caves and rock crevices between 12 and 20 m depth off two locations of Santiago Island, Cape Verde Islands. The species differs from all currently described congeners by the combination of the following characters: (1) 27 vertebrae, (2) second dorsal fin I + 10, (3) posterior quarter of predorsal region in front of first dorsal fin origin scaled, with several rows of cycloid scales, (4) body squamation cycloid anteriorly and ctenoid posteriorly, (5) scales in the lateral series 30–32, (6) anterior oculoscapular canal present, (7) preopercular head canal absent, (8) suborbital row 7 each a single papilla, (9) suborbital rows 2 and 4 close to orbit, and by (10) branchiostegal membranes uniformely black below preopercle, forming a V-shaped mark. Definitions for all used meristic counts are presented to serve as a reference for gobioid meristic studies. The genus is rediagnosed to accommodate recently described Didogobius species.

Two new species of feather mites (Acarina: Psoroptidia) from the Oriental Magpie-Robin, Copsychus saularis (Passeriformes: Muscicapidae)

Two new feather mite species from the bird host Copsychus saularis (Linnaeus) collected in Indonesia (Kalimantan) are described: Dolichodectes latilobus n. sp. (Proctophyllodidae, Pterodectinae), and Trouessartia saularis n. sp. (Trouessartiidae). The new species, Dolichodectes latilobus, has the following distinctive characters: in males, the opisthosomal lobes are widened in the posterior half; the opisthoventral shields are fused, forming a single shield that covers ventrally the posterior quarter of the body; legs I have longitudinal crest-like processes ; and setae ra on these legs are spiculiform. In females of D. latilobus, the posterior margin of the hysteronotal shield has a deep median invagination, and epimerites II extend to the level of the anterior margin of epigynum. The males of T. saularis have the adanal apodemes with two narrow lateral membranes, and the females have the terminal cleft width smaller than the opisthosomal lobe width, and the collar of the spermatheca cover 1/2 from the length of secondary spermaduct.

Morphological peculiarities of the hard palate

Our results were obtained on a total of 48 adult human skulls, assessing the morphological characteristics of the hard palate, measuring the palatine processes and analyzing the sutures (intermaxillary, interpalatine and maxillo-palatine); were determined the size, shape and features of the palatine foramens and incisive fossa. For the incisive fossa we describe three shapes: oval, round and rhombic. In 2 cases the incisive fossa was absent, being replaced by three round holes arranged in a triangle. The palatine process has a very irregular inferior face, being smoother only in its posterior quarter. Each palatine process of maxilla has a trapezoidal shape with the lesser base oriented anteriorly. The median palatine suture starts at the middle of the posterior circumference of the incisive fossa and ends, more often, on the line between second and third molars. The suture may be regular, located on the midline, so the two palatine processes of the maxilla are symmetrical and of equal size. The horizontal palatine lamina is thin, smooth and glossy, with very few vascular openings on its surface, mostly on its sides. The transverse palatine suture is most commonly curved posteriorly, with irregular contour and with an oblique posterior-lateral traject; it ends at the large palatine foramen. The large palatine foramens are voluminous, sometimes larger than the incisor one. The most common shape is oval and less frequently are rounded. The lesser palatine foramens are variable in number from 1 to 5; commonly are two on each side.

Defining the safe working zones using the minimally invasive lateral retroperitoneal transpsoas approach: an anatomical study

ObjectThe lateral retroperitoneal transpsoas approach is being increasingly employed to treat various spinal disorders. The minimally invasive blunt retroperitoneal and transpsoas dissection poses a risk of injury to major nervous structures. The addition of electrophysiological monitoring potentially decreases the risk of injury to the lumbar plexus. With respect to the use of the direct transpsoas approach, however, there is sparse knowledge regarding the relationship between the retroperitoneum/psoas muscle and the lumbar plexus at each lumbar segment. The authors undertook this anatomical cadaveric dissection study to define the anatomical safe zones relative to the disc spaces for prevention of nerve injuries during the lateral retroperitoneal transpsoas approach.MethodsTwenty lumbar segments were dissected and studied. The relationship between the retroperitoneum, psoas muscle, and the lumbar plexus was analyzed. The area between the anterior and posterior edges of the vertebral body (VB) was divided into 4 equal zones. Radiopaque markers were placed in each disc space at the midpoint of Zone III (middle posterior quarter). At each segment, the psoas muscle, lumbar plexus, and nerve roots were dissected. The distribution of the lumbar plexus with reference to the markers at each lumbar segment was analyzed.ResultsAll parts of the lumbar plexus, including nerve roots, were found within the substance of the psoas muscle dorsal to the posterior fourth of the VB (Zone IV). No Zone III marker was posterior to any part of the lumbar plexus with the exception of the genitofemoral nerve. The genitofemoral nerve travels obliquely in the substance of the psoas muscle from its origin to its innervations. It emerges superficially and anterior from the medial border of the psoas at the L3–4 level and courses along the anterior medial fourth of the L-4 and L-5 VBs (Zone I). The nerves of the plexus that originate at the upper lumbar segments emerge from the lateral border of the psoas major and cross obliquely into the retroperitoneum in front of the quadratus lumborum and the iliacus muscles to the iliac crest.ConclusionsWith respect to prevention of direct nerve injury, the safe anatomical zones at the disc spaces from L1–2 to L3–4 are at the middle posterior quarter of the VB (midpoint of Zone III) and the safe anatomical zone at the L4–5 disc space is at the midpoint of the VB (Zone II–Zone III demarcation). There is risk of direct injury to the genitofemoral nerve in Zone II at the L2–3 space and in Zone I at the lower lumbar levels L3–4 and L4–5. There is also a potential risk of injury to the ilioinguinal, iliohypogastric, and lateral femoral cutaneous nerves in the retroperitoneal space where they travel obliquely, inferiorly, and anteriorly to the reach the iliac crest and the abdominal wall.

Seasonal distribution and ecology of three helminth species infecting carp (Cyprinus carpio) in northwest Iowa, U.S.A.

The intestinal helminths most frequently infecting 522 Little Sioux River and 255 Lower Gar Lake carp (Cyprinus carpio) were Khawia iowensis, Pomphorhynchus bulbocolli, and Capillaria catostomi. Prevalence and mean intensity of K. iowensis were significantly higher in Little Sioux River than in Lower Gar Lake carp. Prevalence and mean intensity of P. bulbocolli and mean intensity of C. catostomi were significantly higher in Lower Gar Lake than in Little Sioux River carp. During 1979–1981, the prevalence and mean intensity of K. iowensis were highest in summer 1979 and summer 1980. Pomphorhynchus bulbocolli and C. catostomi were nonseasonal in prevalence and mean intensity. All three helminths were overdispersed within the carp population. Khawia iowensis usually occurred in the anterior third of the carp gut. Capillaria catostomi was found throughout the intestine, but most worms occurred in the posterior quarter of the gut in light infections. Pomphorhynchus bulbocolli exhibited a preference for the posterior third of the intestinal tract. Significant correlation coefficients were calculated between carp length and prevalence and (or) mean intensity of Little Sioux River K. iowensis and P. bulbocolli. Male and female carp had similar prevalences and mean intensities of each parasite species.

Estimation of Post-Mortem Interval from Rectal Temperature by Use of Computer

The simulation model of the approximate equations derived from the infinite cylinder was used to investigate the applicability of the theoretical curve to the actual one of rectal temperature. The rectum was found by the computer tomography to be near to the junction of the anterior three-quarters and the posterior quarter inside the body, and this result was employed in the simulation. The method of estimating the postmortem interval, in which two recordings of rectal temperature were used, was considered to be useful enough as it can be applied to any case in practice. As reported by Akaishi et al., fluctuation of less than 2 °C in the ambient temperature was shown by the simulation to have little effect on the rectal temperature curve.

Morphology and taxonomy of Rhabdias spp. (Nematoda: Rhabdiasidae) from reptiles and amphibians of southern Ontario

Rhabdias americanus n.sp., Rhabdias ranae Walton, 1929, Rhabdias fuscovenosa (Railliet, 1899), and Rhabdias eustreptos (MacCallum, 1921) from amphibians and reptiles of southern Ontario are described. Rhabdias americanus n.sp. and R. ranae have two large lateral pseudolabia beside the oral opening whereas R. fuscovenosa and R. eustreptos each have six lips arranged in lateral groups of three. Rhabdias americanus n.sp. is distinguished from R. ranae by the shape of the pseudolabia and by the presence of a cuticular ring on the posterior border of the buccal cavity which is absent in the buccal cavity of R. ranae. Rhabdias fuscovenosa is distinguished from R. eustreptos by its significantly smaller size and by the shape of the posterior quarter of the body which is straight in R. fuscovenosa and corkscrew shaped in R. eustreptos. Rhabdias fuscovenosa is the only species examined in which eggs in the uteri of gravid hermaphrodites were always at an early cleavage stage of development. In other species examined most eggs in the uteri contained first-stage larvae.