Remarkable papillomas in white sturgeons,Acipenser transmontanus, reared in an aquarium

Papillomatous growths on the ventral surface of the body and paired fins of the white sturgeon,Acipenser transmontanus Richardson, were described histologically with the aid of light and electron microscopy. Contrary to the usual state of intact squamous epithelium being equipped with microridges, no such surface structures were apparent in the papillomatous tissue. The growths appeared to be an aberrant elevations of proliferated dermal tissue, which sustains the hyperplastic Malpighian layer consisting of the stratum spinosum (prickle cell layer) and sbasale. Many intercellular bridges were found, constructed from prominent projections, with distinct demosomes and many tonofilaments. The likely causative agent was mechanical irritation between the small aquarium tank and growing sturgeon, since no viral and/or parasitic inclusion bodies were encountered in the cells.     

Observations on the olfactory organ of adult and juvenile Octopus joubini.

The olfactory organ has an epithelium containing many sense cells and a large subepithelial mass of receptor cells. The epithelium includes cells with cup-shaped, ciliated endings, and hollow, flask-shaped sense cells with ciliated cavities that open to the surface, through a small pore. Below the epithelium are large hollow cells with ciliated cavities and distal processes that either form patent connections between the ciliated cavity and the surface or have a ciliated ending at the surface. There are many synapses between processes in the olfactory nerve. The possible chemosensory function of the olfactory organ is discussed.     

Early morphological development ofOmobranchus fasciolatoceps andO. Punctatus (Blenniidae: Omobranchini) reared in an aquarium

Larval and juvenile development of two blenniids,Omobranchus fasciolatocepts andO. punctatus, is described using eggs collected from natural waters in Tokyo Bay and incubated in an aquarium. These larvae and juveniles are compared with those of two otherOmobranchus species,O. elegans andO. loxozonus, distributed widely in Japan.Onobranchus punctatus is characterized by a unique, pointed snout in preflexion larvae, no melanophores proximally on the lower part of the pectoral fins in flexion and postflexion larvae, and pterygiophores projecting externally as blades between the dorsal and anal fin-rays in postflexion larvae and juveniles.Omobranchus fasciolatoceps has the following characteristics: a few melanophores on the fore-and mid-brain, but none on the hind-brain in preflexion larvae; no melanophores on the cleithral symphysis in flexion and postflexion larvae; no external pterygiophore blades in postflexion larvae and juveniles; and a unique dorsal skin flap on the head in juveniles. Ontogenetic developement of dorsal and anal pterygiophores is described forO. fasciolatoceps andO. punctatus. InO. punctatus, the postero-distal part of each proximal radial projects remarkably to form the external blades between the soft fin-rays, whereas the external blades between the fin spines are formed by fusion of a dermal bone developed from the antero-distal part of each proximal radial with the adjacent distal radial.     

Some Aspects of Hole-Boring Predation by Octopus vulgaris

Octopus vulgaris prey upon many gastropod species by boringholes in the shell, weakening the prey with a venom, removingthe entire prey, and eating it. When offered Strombus raninusthe Octopus quickly grasped the conch with one or a few arms,checked for occupancy by inserting an arm tip into the aperture,and passed the shell under the web to the mouth. The shell washeld against the buccal mass by the circumoral suckers and raspedrepeatedly with the radula, repositioned, and rasped again.There were brief pauses of apparent inactivity between the periodsof active rasping. The shell was penetrated at an approximatemaximal rate of 1.25 mm per hour. The boreholes averaged 0.93mm in outer diameter, 0.47 mm in inner diameter and 0.88 mmin depth. The boreholes were extremely variable in shape, size,and position on the spire. There was a marked preference forindividual animals to bore in a particular sector of the spire.Apparently the animals orient the shells by using the lip asa point of reference because lipless shells had the boreholesrandomly distributed around the shell.     

Octopus joubini (Mollusca: Cephalopoda): a detailed study of growth through the full life cycle in a closed seawater system

Twenty individual pygmy octopuses, Octopus joubini , were reared at 25°C from hatching to maturity on a quantified diet of live crabs in closed (recirculating) natural seawater systems. At 24 week intervals the animals were narcotized, weighed and measured. There was 85% survival to sexual maturity.
Growth rates were highest during the first four weeks of exponential growth. Beyond four weeks, growth rates steadily declined and growth became logarithmic in form. Female octopuses grew slightly faster than males and attained a larger size at maturity. The length-weight relationship showed male Octopus joubini to weigh more than females at a given mantle length. This species displays slight allometric growth resulting in changing body proportions through the life cycle. Relative food intake is highest at hatching and decreases with age. Mean gross growth efficiency over the life span was approximately 40%.     

Zoo and aquarium webcams: an informed view

Providing webcams for public viewing is a relatively new but growing phenomenon among zoos and aquariums. Reasons for incorporating this programmatic feature are varied, and no guidelines exist to aid institutions considering webcam installations. Decision makers need to know how much effort the cameras require as well as how successful other zoos have found them to be. We evaluated existing webcams and provide an overview of their characteristics, including reliability. Quantitative evaluations provided by zoo/aquarium staff and by zoo members indicate generally positive perceptions of webcams, whereas staff acknowledge a notable level of effort required. Here, we strive to offer guidelines that will help institutions considering this venture.     

Extraintestinal gamogony of Aggregata octopiana in the reared common octopus (Octopus vulgaris) (Cephalopoda: Octopodidae)

Aggregata octopiana (Apicomplexa, Aggregatidae) is the most prevalent coccidian in the wild common octopus (Octopus vulgaris), whose heteroxenous life cycle includes gamogony and sporogony undergoing in the octopus digestive tract. In the infected reared octopi, we observed an unusual extraintestinal distribution of the coccidian, with both gamogony and sporogony ongoing in dermal and gill tissue. Oocysts and macrogamonts were embedded in the dermal connective tissue of octopian arms, demarcated by a thin cyst wall or multilayered dark membrane. In gill connective and epithelial tissue all developmental stages were observed, eliciting hemocytic infiltration. Sometimes a complete substitution of the tissue by cysts and developmental stages occurred, resulting in necrosis of gill tissue.     

Some observations on the dentition of an isolated group in northeast Poland.

Clinical examination of the teeth and the mouth was carried out on a group of 133 "Old Believers," 54 males and 79 females, and a control group of 138 Poles living in the same area of Augostova in northeast Poland, 63 males and 75 females. Studying the frequency of Carabelli's cusp, shovel-shaped incisors, missing teeth, microdonita, supernumerary teeth, and torus palatinus in both groups, it was found that Carabelli's cusp and torus palatinus are more frequent among Poles. Such differences could be attributed to differences in ethnic origin of the two groups.     

Electron-microscopic observations of the gravity receptor epithelia of normal and spinner juvenile Octopus maya

Summary Light and electron microscopy of the gravity receptor epithelia (maculae) of statocysts of normal and spinner juvenile Octopus maya showed differences between the structures of the hair cells, supporting cells, and afferent neurons of these cephalopods. The maculae of spinner animals were approximately 30% smaller in their surface area and had 40% fewer hair cells. Moreover, the average distance between randomly-chosen hair bundles in scanning electron micrographs of maculae of normal animals was significantly greater (4.33±6.47 m) than those of maculae of spinner animals (3.38±4.90 m; P<0.0001). The sectional area of the supporting cell's microvilli in spinners maculae was larger (0.16±0.18 m) than those of normal (0.10±0.10 m; P<0.0001) O. maya. The morphological differences observed between certain structural components of the maculae of normal and spinner O. maya may be related to the absence and/or malformation of the neuroepithelial suprastructures in spinners. This may have direct or indirect effects related to their inability to orient to gravity with these organs.     

Wereanimals in Europe and Africa: Some practical observations on an esoteric role

Beliefs in the existence of wereanimals, which were held by members of societies in Europe and in Africa, were remarkably similar. The transforming techniques and the behavior of the wereanimals were believed to be the same in the two areas. Further, it appears that beliefs concerning wereanimals in Europe and Africa should not be viewed as nonverifiable mythology since some of them can be supported by. empirical data. Suggestions for field research which could provide additional illumination on this latter point will be made