Remarks on “ Two new species of Tornidae (Caenogastropoda,Rissooidea) from Espírito Santo,Brazil,” by Luiz Ricardo Simone ( ZooKeys 238: 77–85, 2012) and a plea for improvement in ZooKeys editorial policy

The monotreme genus Zaglossus, the largest egg-laying mammal, comprises several endangered taxa today known only from New Guinea. Zaglossus is considered to be extinct in Australia, where its apparent occurrence (in addition to the large echidna genus Megalibgwilia) is recorded by Pleistocene fossil remains, as well as from convincing representations in Aboriginal rock art from Arnhem Land (Northern Territory). Here we report on the existence and history of a well documented but previously overlooked museum specimen (skin and skull) of the Western Long-Beaked Echidna (Zaglossus bruijnii) collected by John T. Tunney at Mount Anderson in the West Kimberley region of northern Western Australia in 1901, now deposited in the Natural History Museum, London. Possible accounts from living memory of Zaglossus are provided by Aboriginal inhabitants from Kununurra in the East Kimberley. We conclude that, like Tachyglossus, Zaglossus is part of the modern fauna of the Kimberley region of Western Australia, where it apparently survived as a rare element into the twentieth century, and may still survive.     

Avian orientation: the pulse effect is mediated by the magnetite receptors in the upper beak

Migratory silvereyes treated with a strong magnetic pulse shift their headings by approximately 90°, indicating an involvement of magnetite-based receptors in the orientation process. Structures containing superparamagnetic magnetite have been described in the inner skin at the edges of the upper beak of birds, while single-domain magnetite particles are indicated in the nasal cavity. To test which of these structures mediate the pulse effect, we subjected migratory silvereyes, Zosterops l. lateralis, to a strong pulse, and then tested their orientation, while the skin of their upper beak was anaesthetized with a local anaesthetic to temporarily deactivate the magnetite-containing structures there. After the pulse, birds without anaesthesia showed the typical shift, whereas when their beak was anaesthetized, they maintained their original headings. This indicates that the superparamagnetic magnetite-containing structures in the skin of the upper beak are most likely the magnetoreceptors that cause the change in headings observed after pulse treatment.     

Ultrastructure of the tail region of the second stage preparasitic larva of the root-knot nematode

Studies on the tail of second-stage infective larvae (L₂s) of Meloidogyne javanica, M. incognita and M. hapla from a region anterior to the rectal gland to the tail tip have revealed the presence of a previously undescribed sensory organ, the caudal sensory organ, in the posterior region of the tail.The extreme tip of the tail consists of solid cuticle and the different zones of this structure are described throughout the tail region. Longitudinal sections through the anus and rectum have revealed that the cortical (external cortical, epicuticle) layer gradually decreases in thickness until its outermost layer appears to merge with the plasma membrane of the rectal inflation or gland. This gland appears to be similar in all three species studied.The two phasmidial glands and their canals are described from transverse sections. Somatic muscle is first found in the region of the anus and it extends anteriorly throughout most of the length of the L₂. Depressor ani muscles which insert on the dorsal surface of the rectum are also described.The rectal gland in the dilated state occupies about three quarters of the diameter of the L₂. It contains a matrix which resembles that extruded from the adult female rectal gland cells. The rectal gland cells contain large amounts of rough endoplasmic reticulum and desmosomes are found close to the junction of these cells and the plasma membrane of the gland itself. More anteriorly in the L₂ most of the area is taken up by large lipid droplets which function as an energy reserve.It is suggested that the rectal gland should not be used as a taxonomic criterion for separating the La_2^S of Meloidogyne because it can vary so much in appearance within the same species.     

Carex tenuirostrata (Cyperaceae), a new species of section Confertiflorae from Zhejiang, China

Carex tenuirostrata, a new species of C. sect. Confertiflorae, is described from Pingyang and Putuo counties of Zhejiang province, China. It is morphologically similar to C. pseudodispalata, but differs in its androgynous lateral spikes; distended perigynia attenuately contracted into a short beak at the apex; ellipsoid-obovoid achenes contracted into a slender beak at the apex; and long-sheathed lower bracts. Scanning electron microscope (SEM) photographs of the achenes of the new species and C. pseudodispalata are provided for comparison.     

A unique cytogenetic system in monotremes

All 3 extant genera of monotremes show a unique kind of cytogenetic system involving the formation of a structurally heterozygous chain multiple apparently coupled with a system of complementary gametic elimination. In the echidna Tachyglossus there are 63 chromosomes in the male and 64 in the female. This is associated with an X₁X₂Y/X₁X₁X₂X₂ sex chromosome system. Additionally in both sexes there are 6 mitotic chromosomes (a-f) which have no obvious homologous partners. At male meiosis these are included with the 3 sex chromosomes in a chain multiple of nine which has the constitution X₁·Y·X₂·f·e·d·c·b·a. This shows convergent orientation at first metaphase leading to the production of two kinds of sperm, namely X₁X₂ eca and Yfdb. Since no individual of either sex has been found homozygous for any of the a-f elements it follows that only gametes carrying different combinations of the three unpaired elements give rise to viable offspring. Whether this depends on gametic selection or on zygotic lethality is not known. An apparently identical system operates in Zaglossus. In the platypus Ornithorhynchus, on the other hand, there are 52 chromosomes in both males and females associated with an XY/XX sex chromosome mechanism and the presence of 4 consistently unpaired elements (a-d) at mitosis. A chain multiple of 10 forms at male meiosis involving the 2 sex chromosomes, the 4 unpaired elements and two of the small pairs of autosomes. Additionally the six longest autosome pairs in Tachyglossus and the X₁ show a polymorphism for size which in heterozygous combination leads to the formation of unequal bivalents at male meiosis.     

Beak length analysis of the Southern Ocean squid Psychroteuthis glacialis (Cephalopoda: Psychroteuthidae) and its use for size and biomass estimation

A detailed analysis of beak length to body size and mass measurements was carried out for the glacial squid Psychroteuthis glacialis, which is an endemic cephalopod species in the Southern Ocean. Beak lengths (lower rostral length) were measured from 211 specimens which had been sampled in the Atlantic sector of the Southern Ocean. The basic idea was to find some calibration model in order to inter- or extrapolate missing mantle length and/or wet body mass data by means of beak lengths. The relationships between beak length and mantle length/wet body mass bear essential information for future use in biomass estimates in Southern Ocean top predators, since beaks of P. glacialis occur frequently in the stomach contents of Antarctic seabirds, seals and toothed whales. Therefore, lower rostral lengths were plotted against both mantle length and wet body mass to determine the relationship between these variables. The relationships had limited scatter and very high coefficients of determination, showing that lower rostral length is a good predictor of the squid's mantle length and wet mass. A non-linear 3rd order polynomial regression of lower rostral length against mantle length was identified as the best fitted calibration model, explaining 93% (R ²) of the associated variance. The relationship between lower rostral length and wet body mass was empirically well fitted through regressing ln-transformed values of lower rostral length against wet body mass, explaining 95% (R ²) of the associated variance. The present investigation provides measurements for a wide size range of P. glacialis individuals compared to earlier studies, which were limited on very small data sets. Accepted: 23 August 1999     

The use of beaks as tools for biomass estimation in the deepwater squid Moroteuthis ingens (Cephalopoda: Onychoteuthidae) in New Zealand waters

Beak lengths (lower rostral length and upper rostral length) were taken for a sample of Moroteuthis ingens which were captured on the Chatham Rise, New Zealand. Beak lengths were plotted against both mantle length and wet weight to determine the relationship between these parameters for future use in biomass estimates in predator analysis. Although M. ingens is markedly sexually dimorphic, with females reaching 5 times the weight of males, there was no obvious sexual dimorphism in either lower or upper rostral length. This resulted in sex-specific relationships between both LRL and mantle length, LRL and weight; and URL and mantle length, and URL and weight. Males appeared to have a curvilinear relationship between beak length and mantle length and beak length and weight (even for log-transformed data). There was also considerable spread in the data in the plot between beak length and weight for females of similar weight. These characteristics of the data makes biomass estimates based on rostral length measurements for this species difficult. Other beak parameters may prove more useful for estimating biomass of M. ingens.     

Conserved expression of mouse Six1 in the pre-placodal region (PPR) and identification of an enhancer for the rostral PPR

All cranial sensory organs and sensory neurons of vertebrates develop from cranial placodes. In chick, amphibians and zebrafish, all placodes originate from a common precursor domain, the pre-placodal region (PPR), marked by the expression of Six1/4 and Eya1/2. However, the PPR has never been described in mammals and the mechanism involved in the formation of PPR is poorly defined. Here, we report the expression of Six1 in the horseshoe-shaped mouse ectoderm surrounding the anterior neural plate in a pattern broadly similar to that of non-mammalian vertebrates. To elucidate the identity of Six1-positive mouse ectoderm, we searched for enhancers responsible for Six1 expression by in vivo enhancer assays. One conserved non-coding sequence, Six1-14, showed specific enhancer activity in the rostral PPR of chick and Xenopus and in the mouse ectoderm. These results strongly suggest the presence of PPR in mouse and that it is conserved in vertebrates. Moreover, we show the importance of the homeodomain protein-binding sites of Six1-14, the Six1 rostral PPR enhancer, for enhancer activity, and that Dlx5, Msx1 and Pax7 are candidate binding factors that regulate the level and area of Six1 expression, and thereby the location of the PPR. Our findings provide critical information and tools to elucidate the molecular mechanism of early sensory development and have implications for the development of sensory precursor/stem cells.     

Inhibition of ATPases by gymnemic acid

A specially prepared and partially fractionated preparation of gymnemic acid compounds were found to be inhibitory to the ATPase system from housefly brain and labellum, and fish brain. Enzyme activity in a homogenate fraction from labellum showed greatest sensitivity to the gymnemic acid preparation. Na⁺-K⁺ ATPase activity from the labellum, which contains the sweet taste sensory receptors, was inhibited by over 92% at a concentration of 4 middot; 10^?6M gymnemic acid. Because gymnemic acid compounds are specific suppressants of sweet receptors, the evidence presented in this paper implies that a portion of the ATPase system may be biochemically important in the sweet-sensing mechanism.     

Brain and behaviour of living and extinct echidnas

The Tachyglossidae (long- and short-beaked echidnas) are a family of monotremes, confined to Australia and New Guinea, that exhibit striking trigeminal, olfactory and cortical specialisations. Several species of long-beaked echidna (Zaglossus robusta, Zaglossus hacketti, Megalibgwilia ramsayi) were part of the large-bodied (10 kg or more) fauna of Pleistocene Australasia, but only the diminutive (2–7 kg) Tachyglossus aculeatus is widespread today on the Australian mainland. We used high-resolution CT scanning and other osteological techniques to determine whether the remarkable neurological specialisations of modern echidnas were also present in Pleistocene forms or have undergone modification as the Australian climate changed in the transition from the Pleistocene to the Holocene. All the living and extinct echidnas studied have a similar pattern of cortical gyrification that suggests comparable functional topography to the modern short-beaked form. Osteological features related to olfactory, trigeminal, auditory and vestibular specialisation (e.g., foramina and cribriform plate area, osseous labyrinth topography) are also similar in living and extinct species. Our findings indicate that despite differences in diet, habitat and body size, the suite of neurological specialisations in the Tachyglossidae has been remarkably constant: encephalisation, sensory anatomy and specialisation (olfactory, trigeminal, auditory and vestibular), hypoglossal nerve size and cortical topography have all been stable neurological features of the group for at least 300,000 years.     

Disorganized Innervation and Neuronal Loss in the Inner Ear of Slitrk6-Deficient Mice

Slitrks are type I transmembrane proteins that share conserved leucine-rich repeat domains similar to those in the secreted axonal guidance molecule Slit. They also show similarities to Ntrk neurotrophin receptors in their carboxy-termini, sharing a conserved tyrosine residue. Among 6 Slitrk family genes in mammals, Slitrk6 has a unique expression pattern, with strong expression in the sensory epithelia of the inner ear. We generated Slitrk6-knockout mice and investigated the development of their auditory and vestibular sensory organs. Slitrk6-deficient mice showed pronounced reduction in the cochlear innervation. In the vestibule, the innervation to the posterior crista was often lost, reduced, or sometimes misguided. These defects were accompanied by the loss of neurons in the spiral and vestibular ganglia. Cochlear sensory epithelia from Slitrk6-knockout mice have reduced ability in promoting neurite outgrowth of spiral ganglion neurons. Indeed the Slitrk6-deficient inner ear showed a mild but significant decrease in the expression of Bdnf and Ntf3, both of which are essential for the innervation and survival of sensory neurons. In addition, the expression of Ntrk receptors, including their phosphorylated forms was decreased in Slitrk6-knockout cochlea. These results suggest that Slitrk6 promotes innervation and survival of inner ear sensory neurons by regulating the expression of trophic and/or tropic factors including neurotrophins from sensory epithelia.     

QUANTITATIVE ASPECTS OF CUTANEOUS SENSORY ADAPTATION. I

1. Adaptation of tactile receptors in the skin of the frog to excitation by an intermittent jet of air is measured and correlated with certain properties of a series of notched discs used to interrupt the air stream. 2. Adaptation in fifteen cases is found to be described by either one of two empirical formulas, or t = -k log f + C, for nine preparations t = a f^-b, for six preparations where f is the per cent frequency at time t and -k and -b are constants defining the rate of adaptation.     

Avian Magnetoreception: Elaborate Iron Mineral Containing Dendrites in the Upper Beak Seem to Be a Common Feature of Birds

The magnetic field sensors enabling birds to extract orientational information from the Earth''s magnetic field have remained enigmatic. Our previously published results from homing pigeons have made us suggest that the iron containing sensory dendrites in the inner dermal lining of the upper beak are a candidate structure for such an avian magnetometer system. Here we show that similar structures occur in two species of migratory birds (garden warbler, Sylvia borin and European robin, Erithacus rubecula) and a non-migratory bird, the domestic chicken (Gallus gallus). In all these bird species, histological data have revealed dendrites of similar shape and size, all containing iron minerals within distinct subcellular compartments of nervous terminals of the median branch of the Nervus ophthalmicus. We also used microscopic X-ray absorption spectroscopy analyses to identify the involved iron minerals to be almost completely Fe III-oxides. Magnetite (Fe II/III) may also occur in these structures, but not as a major Fe constituent. Our data suggest that this complex dendritic system in the beak is a common feature of birds, and that it may form an essential sensory basis for the evolution of at least certain types of magnetic field guided behavior.     

Beak length analysis of arrow squidNototodarus sloanii (Cephalopoda: Ommastrephidae) in southern New Zealand waters

 Beak length analysis was undertaken for the arrow squid Nototodarus sloanii in the New Zealand sector of the Southern Ocean between Stewart Island and the Auckland Islands. N. sloanii has a restricted range and is endemic to the waters around New Zealand and its associated southern islands, where it supports a fishery and is preyed upon by a number of fishes, marine mammals and birds. Lower rostral length (LRL) and upper rostral length (URL) were analysed to see how these beak measurements related to both mantle length (ML) and wet weight (W). Both lower and upper rostral lengths could be used as useful predictors of ML and W in N. sloanii, as relationships had limited scatter and high correlation coefficients. The relationships between LRL and ML, and URL and ML were only linear after regressing log-transformed values of beak length against ML. However, the relationships between LRL and W, and URL and W were linear without transforming either the x or y values. These results are different from previously published beak length analyses of Nototodarus in New Zealand waters. Received: 30 March 1995/Accepted: 4 August 1995     

Epithelium of lips and associated structures of the Indian major carp,Catla catla

Structural organization of the epithelium of the lips and associated structures of the Indian major carp,Catla catla, is described. The upper lip is thin and is associated on its dorsal side with a membranous fold of skin and the rostral cap. In contrast, the lower lip is thick and very conspicuous. It is associated on its ventral side with a fold of skin between it and the ventral head skin. The lower lip is divided into a non-projectile portion, a projectile portion and an intermediate groove region. The projectile portion remains folded covering a part of the ventral head skin when the mouth is closed. Their role in relation to the formation of the characteristic feeding tube is discussed. The epithelium of the lips and associated structures is stratified in nature and is composed of the epithelial cells, mucous cells, club cells, lymphocytes and the taste buds. The mucous cells are small, few or even absent and do not appear to secrete profusely at the surfaces of the upper and the lower lips. This suggests that the lips inCatla catla, which feeds on micro-organisms, do not need extra lubrication for protection against abrasion during feeding. In the epithelium at the folds of skin, the voluminous mucous cells secrete profusely and provide extra lubrication to their surface. This reduces the resistance to surface drag during stretching and enables the jaws to protrude with increasing efficiency and swiftness. The club cells are developed additionally to complement the mucous cells in the rostral cap and the upper lip epithelium. Their primary function appears protective in some way, which needs further confirmation. The taste buds, though few in the lower lip, are located in a good number in the upper lip on the characteristic epithelial papillae-like projections, and are projected at the surface. These have been associated with the acute gustatory sense of the fish. The taste buds are absent on the folds of skin where they may not be of much significance.     

A high-affinity calcium-stimulated ATPase activity in the hen oviduct shell gland

The hen oviduct shell gland is a highly active calcium-transporting epithelial tissue which is responsible for the mineralization of the egg shell. We have identified a calcium-stimulated ATPase present at high specific activity in membrane preparations from shell gland mucosal shavings. In the presence of optimal MgCl₂ (5 mm) and a Ca²⁺ buffer, ATP hydrolysis was stimulated by addition of low concentrations of free Ca²⁺ (K_0.5 ~0.4 μm); but not by similar concentrations of Mn²⁺, Zn²⁺, Co²⁺, or La²⁺. This stimulation was specific for ATP; there was little or no effect of Ca²⁺ on hydrolysis of ADP, AMP, GTP, ITP, or p-nitrophenyl phosphate. Calcium-stimulated ATPase activity was inhibited by chlorpromazine, trifluoperazine, and quercetin, as well as by sulfhydryl-blocking agents, but not by oligomycin or ouabain. No significant effect of calmodulin was observed. Finally, low concentrations of free Ca²⁺ (10 to 100 μm) in the presence or absence of Mg²⁺ stimulated transfer of ³²P from [γ-³²P]ATP to a 105,000 molecular weight shell gland membrane protein. This phosphoprotein was sensitive to hydrolysis by heating or by hydroxylamine treatment at acidic pH, and its formation was not inhibited by addition of K⁺. The specific activity of Ca²⁺-ATPase in total membrane preparations from laying hen shell gland ranged from 80 to 150 nmol/min/ mg protein, similar to or greater than levels found in purified plasma membrane fractions from a variety of tissues. No significant activity was found in membrane preparations from the magnum or isthmus regions of the oviduct, which are not involved in egg shell calcification. The characteristics of the Ca²⁺-ATPase, its high specific activity, and its preferential localization in the shell gland region of the oviduct suggest a role for an ATP-dependent calcium transport system in egg shell mineralization.     

Effects of divalent ions and drugs on synaptic transmission in phasic electroreceptors in a mormyrid fish

We recorded impulses in afferent nerve fibers innervating two kinds of phasic electroreceptors in a mormyrid fish. We used an isolated preparation of skin, receptors, and sensory nerves to estimate synaptic delays, and to change solution in contact with the receptor-nerve synapse. The minimum delays between stimuli and sensory nerve responses, which must be slightly larger than synaptic delays, are about 0.7 msec in medium receptors and about 0.25 msec in large receptors. This result supports previous suggestions that transmission is chemically mediated in medium receptors and electrically mediated in large receptors. Furthermore, Mg⁺² depresses synaptic transmission in medium receptors, and has little effect on transmission in large receptors. A complex dependence of response on both Mg⁺² and Ca⁺² masks divalent ion dependence of transmission, but a large excess of Mg⁺² cannot completely block transmission in medium electroreceptors. L-glutamate, and not cholinergic drugs, produces a sequence of excitation and depression of medium receptor response which indicates that a similar chemical is the transmitter in the afferent synapse.     

Chemical identification and enzymatic synthesis of a newly discovered lipid class--hydroxyalkylglycerols

We have isolated and identified a new class of alkyl glycerolipids in lipid extracts prepared from the pink portion of the harderian glands of rabbits. After LiAlH₄ reduction, the esterified lipid yields a hydroxyalkylglycerol. Identification was based on chromatography, infrared spectroscopy, and mass spectra of various derivatives of this lipid and of standards prepared chemically. The isomers of the hydroxyalkylglycerols isolated consisted of O-hexadecyl moieties with hydroxyl groups at C-10 and C-11 and of O-octadecyl moieties with hydroxyl groups at C-11 and C-12. In the natural state all of the hydroxyl groups are thought to be esterified with aliphatic moieties, and this lipid class accounts for approximately 80% of the total lipids of the pink harderian gland of rabbits. Enzymatic experiments demonstrated that [1-³H]octadecane-1,12-diol was readily incorporated into the hydroxyalkylglycerols when dihydroxyacetone-P, CoA, ATP, Mg²⁺, and the microsomal fraction of the pink harderian gland were included in the incubations. Thus, it appears that the ether linkage of hydroxyalkylglycerols is biosynthesized in a manner analogous to that previously described for glycerolipids containing unsubstituted O-alkyl moieties.     

Microsomal (Na + K)-activated ATPase from frog skin epithelium. Cation activations and some effects of inhibitors

A method is described for the extraction of microsomal ouabain-sensitive (Na⁺ + K⁺)-activated ATPase from separated frog skin epithelium. The method yields a microsomal fraction containing (Na⁺ + K⁺)-stimulated activity in the range of 30–40 nmol · mg⁻¹ · min⁻¹ at 26 °C. This portion, which is also ouabain sensitive, is about half of the total activity in media containing Mg²⁺, Na⁺ and K⁺. These preparations also contain Mg²⁺-dependent or Ca²⁺-dependent activities which are not additive and which are not significantly affected by ouabain, Na⁺, K⁺ or Li⁺.The activations of the ouabain-sensitive ATPase activity by Mg²⁺, Na⁺, and K⁺ are similar to those described in other tissues. It is found that Li⁺ does not substitute for Na⁺ as an activator but in high concentrations does produce partial activation in the presence of Na⁺ with no K⁺. These results are pertinent to the reported observations of ouabain-sensitive Li⁺ flux across frog skin. It is concluded that this flux is not apparently due to a direct activating effect of Li⁺ on the sodium pump.     

Differences of skin morphology in Bos indicus,Bos taurus,and their crossbreds

Cutaneous evaporation is the main avenue by which cattle dissipate heat via the involvement of sweat glands and other skin components. The difference in skin morphology between B. indicus and B. taurus has been recognized, as well as differences in their ability to tolerate heat. The objective of this study was to compare skin morphology between B. indicus, B. taurus, and their crossbreds. Skin samples of Sahiwal (B. indicus) (n?=?10, reddish brown skin) and Holstein Friesian (HF) (B. taurus) (n?=?10, black and white skin) and crossbred of HF75% (n?=?10, black and white skin) and HF87.5 % (n?=?10, black and white skin) were biopsied for histological study, followed by measurement of skin components. The results indicated that breed significantly affected sweat gland morphology. The shape of the sweat gland, as indicated by the ratio of length/diameter, in Sahiwal was baggier in shape compared to HF (5.99 and 9.52) while values for crossbreds were intermediate (7.82, 8.45). The density and volume of sweat glands in Sahiwal (1,058 glands/cm²; 1.60 μ³?×?10^?6) were higher than in HF (920 glands/cm²; 0.51 μ³x10^?6) and crossbreds, both HF 75 % (709 glands/cm²; 0.68 μ³?×?10^?6) and HF 87.5 % (691 glands/cm²; 0.61 μ³?×?10^?6) respectively. However, capillary surface area was greater for HF (2.07 cm²) compared to Sahiwal (1.79 cm²); accordingly, the lower genetic fraction of HF in crossbred cattle showed less capillary surface area (1.83 and 1.9 cm² for HF75% and HF87.5 %) (P?<?0.01). Nerve density was not significantly different between Sahiwal and HF but was higher in the crossbred (P?<?0.01) cattle. Moreover, the effect of skin color (black and white) was evaluated and it was found that there was an interaction (P?<?0.01) between breed and skin color on the skin components. This study reveals that there are differences in skin morphology among B. indicus, B. taurus and their crossbreds, with these differences being more or less related to the genetic fraction of HF. This may imply that capability for cutaneous evaporative heat loss and tolerance to heat in crossbred cattle could be related to skin morphology.