Tyzzeria chalcides N. Sp. from the Ocellated Skink,Chalcides ocellatus1

ABSTRACT A new species of coccidium, Tyzzeria chalcides, is described from the ocellated skink, Chalcides ocellatus, from Egypt. Meronts occur in the epithelial cells of the bile ducts and gamonts within the epithelial cells of the gall bladder. Fully sporulated oocysts are cylindrical (L/W ratio 1.88) without a micropyle, oocyst residuum, or polar granule and contain eight spindle-shaped sporozoites and no sporocysts. Sporulation is completed within the gall bladder lumen. Comparison with other species of the genus found in reptiles indicates that it is a new species.     

Phylogeographic inferences from the mtDNA variation of the three-toed skink, Chalcides chalcides (Reptilia: Scincidae)

Genetic diversity was analyzed in Chalcides chalcides populations from peninsular Italy, Sardinia, Sicily and Tunisia by sequencing 400 bp at the 5' end of the mitochondrial gene encoding cytochrome b (cyt b) and by restriction fragment length polymorphism (RFLP) analysis of two mitochondrial DNA segments (ND-1/2 and ND-3/4). The results of the phylogenetic analysis highlighted the presence of three main clades corresponding with three of the four main geographical areas (Tunisia, Sicily and the Italian peninsula), while Sardinia proved to be closely related to Tunisian haplotypes suggesting a colonization of this island from North Africa by human agency in historical times. On the contrary, the splitting times estimated on the basis of cyt b sequence data seem to indicate a more ancient colonization of Sicily and the Italian Peninsula, as a consequence of tectonic and climatic events that affected the Mediterranean Basin during the Pleistocene. Finally, the analysis of the genetic variability of C. chalcides populations showed a remarkable genetic homogeneity in Italian populations when compared to the Tunisian ones. This condition could be explained by a rapid post-glacial expansion from refugial populations that implied serial bottlenecking with progressive loss of haplotypes, resulting in a low genetic diversity in the populations inhabiting the more recently colonized areas.     

Histology of abortive egg sites in the uterus of a viviparous,placentotrophic lizard,the skink Chalcides chalcides

Although abortive uterine eggs are often assumed to be resorbed by females of the viviparous skink Chalcides chalcides, little microscopic evidence of resorption of such eggs is available. Oviducts from pregnant female C. chalcides in which egg resorption was inferred were examined histologically to seek a morphological basis for resorption. Uterine histology at the site of abortive eggs was very similar to that of lizards in early pregnancy. The uterine epithelium consisted of a monolayer of pseudostratifed columnar cells that showed no evidence of yolk phagocytosis. The uterine lamina propria exhibited shell glands and modest vascularity, typical of early gestation, and contained neither yolk droplets nor accumulating leukocytes. Unattenuated regions of the lamina propria contained occasional macrophages and mast cells, some of the latter of which were undergoing degranulation. The abortive eggs often were collapsed with ruptured shell membranes, and some were undergoing extrusion from the incubation chambers down the oviduct. In eggs that had begun developing, extraembryonic ectoderm and endoderm were atypical in location, and had failed to enclose yolk leaking from the eggs. Oviducts sampled from later in the reproductive season were reproductively inactive, and showed no trace of abortive eggs or egg components. We postulate that abortive eggs are extruded from the oviduct by pregnant females under conditions of physiological stress, as a means of enhancing future reproductive effort. J. Morphol. 235:97–108, 1998. © 1998 Wiley-Liss, Inc.     

Two New Species of Isospora from the Desert Skink (Chalchides ocellatus) from the Egyptian Desert

Isospora chalchidis n. sp. and Isospora eimanae n. sp. were isolated from the desert skink, Chalchides ocellatus , order Squamata, from Egypt. Sporulated oocysts of I. chalchidis n. sp. were spheroidal 19 × 19 (18–20.5 × 18–20.5) μm with a 2–layered walled. Oocysts lacked a micropyle and residuum and few polar granules were present. Sporocysts were lemon-shaped 12.2 × 6.5 (9.5–13 × 5–8) μm with a Stieda body and sporocyst residuum but without a substiedal body. Isospora eimanae n. sp. were spheroidal 18.5 × 18.5 (17–19.5 × 17–19.5) μm with a 2–layered wall. There were oocysts without residuum or polar granule, but with small micropyle at 1 end. Sporocysts were ovoid 12 × 8.5(11–13 × 7.5–9) μm with a small Stieda body and sporocyst residuum but without a substiedal body.     

The effect of thyroxine on the oxygen consumption of the ocellated skink, Chalcides ocellatus (Forskal)

Acutely administered thyroxine caused significant increase in the whole body rate of oxygen consumption of C. ocellatus at temperatures between 4 and 25 degrees C. No significant increase in the oxygen consumption was observed over the voluntary body temperature range of 30-40 degrees C.     

Isospora viridanae N. Sp., an Intranuclear Coccidian Parasite from the Canarian Skink, Chalcides viridanus (Lacertilia: Scincidae)

A caryotropic species of coccidium, Isospora viridanae n. sp. (Apicomplexa: Eimeriidae). has been found as a parasite in the Canarian skink, Chalcides viridanus Gravenhorst, 1851, from Tenerife, Spain, and is described here as a new species. Fully sporulaled oocysts of Isospora viridanae are spherical and measure 21.6 (1 7.6–23.4) nm in diameter. Mtcropyle, oocyst residuum and polar granule are ali absent. Oocysts of this coccidian, with a smooth bilayered wall, contain 2 ovoid sporocysts 13.2 (11.7–14.0) by 9.5 8.2–10 5) μm. A sporocyst residuum is present as well as a Stieda body and a substieda body. Most oocysts are found to be at the beginning of sporulanon when excreted and show 2 spherical sporoblasts. Sporulation is completed within 24 to 48 h at 23 × 2°C Sporozoites are 13–14 μm long and are about 2.5–3 μ m wide. Endogenous stages of schizogony and gamogony develop in the nuclei of epithelial cells from the small intestine of the skink. Comparisons with other species of the genus found in lacertilian hosts indicate that it is a new species.     

Ultrastructural features of gametogenesis during the life cycle in Branchiura sowerbyi Beddard (Oligochaeta,Tubificidae)

An ultrastructural analysis of the gametogenetic phases in Branchiura sowerbyi, a tubificid oligochaete, has been accomplished. These phases mostly conform to the usual pattern for the family, however, some interesting peculiarities are pointed out. The regression of sexual apparatus after reproductive period and its regeneration up to a new period of sexual maturity, has been followed throughout the year.     

Observations on Askenasia volvox (Claparède & Lachmann, 1859)

Specimens of Askenasia volvox from southwestern Indiana have a variable body shape and a size range of 29 × 22 μ m to 42 × 27 μ m. The pectinelles, membranelles, and cirri each number 47–48, and respectively have a length of 8–10, 20, and 30 μ m. The pectinelles arise from ciliary rows consisting of ～10 kinetosomes, and every membranelle originates from 2 adjacent rows of ～14–17 kinetosomes. Different algae as well as Bodo and certain other protozoa are ingested. The macronucleus, micronucleus, the cytoplasm and its inclusions, trichites, the function of the contractile vacuole, and movements and behavior are described.     

Observations on the Endogenous Stages of Eimeria confusa Joseph, 1969 from the Grey Squirrel Sciurus carolinensis*

SYNOPSIS. Stages in the endogenous cycle of Eimeria confusa from the grey squirrel, Sciurus carolinensis, are described from mixed infections with another species, Eimeria lancasterensis. All corresponding stages were markedly different in the 2 species. In E. confusa infections, the parasites were located below the host cell nuclei of the epithelial cells of the villi of the jejunum and ileum. Mature schizonts were ellipsoidal, averaged 20.9 × 18.6 μm and had 18–30 merozoites. The mature microgamonts measured 34.3 × 24.7 μm and had hundreds of microgametes. Mature macrogametes were ovoid, averaged 31.3 × 25.6 μm, and contained 2 kinds of plastic granules.     

Ultrastructural Observations on the Larva of Loxosoma pectinaricola Franzén (Entoprocta,Loxosomatidae)

The larva of Loxosoma pectinaricola Franzén has been studied using scanning and transmission electron microscopy. The embryo develops surrounded by an egg envelope attached to the brood chamber. The newly released larva measures about 100 μm in length and is characterized by a prominent apical organ, stalked vesicles, paired lateral sense organs and a prototroch. The apical organ consists of at least four cell types: (1, 2) two types of ciliated cells, (3) vacuolated cells and (4) myoepithelial cells. The apical organ and frontal ganglion are tightly juxtaposed in the upper tier of the episphere. The stalked vesicles each consisting of two cells are unique evaginations of the epidermis. There are about twenty stalked vesicles with a maximum diameter of about 20.0 μm. The ciliated, knob-shaped, paired lateral sense organs are situated fronto-laterally on the episphere. The prototroch is comprised of a row of contiguous prototroch cells each containing about eighteen long cilia. The apical organ, frontal ganglion and paired lateral sense organs are suggested to be sensory structures that play an important role in active locomotion, settlement site selection and metamorphosis.     

A review of the Oriental genus Eudeferunda Chen,Yang & Wilson (Hemiptera,Fulgoromorpha, Achilidae) with description of one new species from Hainan,China

A new species of Eudeferunda Chen, Yang & Wilson, 1989 (Hemiptera: Fulgoromorpha: Achilidae: Plectoderini), Eudeferunda alatea Long & Chen sp. n. from Hainan, China, is described and illustrated. The generic characters are modified, including the addition of male genitalia characters. A key to the species of the genus is provided.     

Five New Species of Lagenophrys (Ciliophora,Peritricha, Lagenophryidae) from the United States with Observations on Their Developmental Stages1

Five species of the loricate genus Lagenophrys were found on freshwater hosts and are described for the first time. Lagenophrys dennisi n. sp., L. incompta n. sp., and L. oregonensis n. sp. are ectosymbionts of astacid crayfish. Lagenophrys foxi n. sp and L. missouriensis n. sp. are ectosymbionts of gammarid amphipods. All five species appear to occur only m North America. Protargol preparations of the five species reveal that the peristomial myoneme is much broader and more extensive in telotrochs and metamorphosing individuals than in adults. Darkly staining bands appearing to be somatic myonemes were also seen underneath the surface of the body and in the center of the body of telotrochs and metamorphosing individuals. The telotroch of Lagenophrys is so different from the adult that it constitutes a true larval form rather than a simple dispersal stage. Structural parallels between the telotroch of Lagenophrys and mobiline peritrichs suggest the hypothesis that mobilines evolved from the telotroch of a sessiline pentrich which had first evolved into a true larval form.     

Ultrastructural Observations on Renal Schizogony of Leucocytozoon dubreuili in the American Robin

SYNOPSIS. The schizogonic development of Leucocytozoon dubreuili in the kidney proximal tubule cells of the American robin, Turdus migratorius , was studied by electron microscopy. Renal schizogony is initiated by the entry of certain hepatic merozoites into cells of the proximal tubules. Development of the schizont consists of a coordinated sequence of events including extensive mitotic nuclear division, multiplication of mitochondria, increase in endoplasmic reticulum and ribosomes, differentiation of membranes, microtubules, micronemes and rhoptries, and cytoplasmic segmentation (cytomere formation). Merozoites form by budding around numerous centers in the schizont and, when mature, are bounded by a single plasma membrane subtended by microtubules. Each merozoite contains a large nucleus, a mitochondrion, and a well developed apical complex consisting of 3 polar rings, paired rhoptries, and numerous micronemes.
An atypical nuclear division observed in some maturing schizonts was characterized by the multiple fission of a nucleus within a persistent outer nuclear membrane and the absence of mitotic spindle apparatus. Alterations in infected renal cells consisted of disorganization and loss of cytoplasmic organelles and the accumulation of lipofuscin-like inclusions.     

摄食对印度蜓蜥代谢率的影响

通过测定摄食后印度蜓蜥雌性成体的耗氧量变化 ,研究摄食特殊热动力作用 (SDA)。动物分为摄食黄粉虫幼虫实验组和禁食对照组 ,两组蜥蜴平均体重无显著差异。测定耗氧量前 ,将所有动物在 3 0℃恒温室内禁食 3d。用容积为 3 0 0ml的封闭式呼吸室测定两组蜥蜴在 3 0℃条件下连续 3d的耗氧量 ,测定间隔时间为 4～ 2 5h。禁食组动物实验期间的耗氧量无显著的时间变异 ,实验组动物耗氧量的时间变异显著 ,这些结果表明摄食影响印度蜓蜥的代谢率。实验组动物摄食 8h后耗氧量已显著大于禁食组 ,摄食 3 0h后两组动物的耗氧量无显著差异。印度蜓蜥达到SDA峰值的平均时间约为 1 2 7h ,SDA峰值耗氧量是禁食对照组动物耗氧量的 1 6倍。印度蜓蜥单次摄食实验中的SDA具有进食后耗氧量迅速增加 ,达到峰值后下降至摄食前水平的典型模式。