Five new and five known species of the genus Tylencholaimus de Man, 1876 (Nematoda: Dorylaimida: Tylencholaimoidea) from Western Ghats of India

Five new and five known species of the genus Tylencholaimus de Man, 1876 are described from the Western Ghats of India. Tylencholaimus macroamphidius sp. nov. has a 0.61–0.85 mm long body, angular lips, large amphid, 8.0–9.0 μm long odontostyle, odontophore with asymmetrical basal knobs, pharyngeal bulb expanding gradually, female genital system mono-prodelphic, and a rounded to conoid tail. Tylencholaimus shamimi sp. nov. has a 0.57–0.71 mm long body, 6.0–7.0 μm long odontostyle, odontophore with basal thickening, pharyngeal bulb expanding gradually, female genital system amphidelphic and a convex-conoid tail. Tylencholaimus southindicus sp. nov. has a 0.44–0.55 mm long body, lip region with distinct labial disc, 4.5–5.5 μm long odontostyle, odontophore with minute basal knobs, pharyngeal expansion abrupt, female genital system mono-prodelphic, and a rounded-conoid to rounded tail. Tylencholaimus striatus sp. nov. has a 0.30–0.34 mm long body with distinctly striated cuticle, 5.0–5.5 μm long odontostyle, odontophore with minute basal knobs, pharyngeal bulb expanding abruptly, female genital system mono-prodelphic, and a conoid tail with bluntly rounded terminus. Tylencholaimus tamiliensis sp. nov. has 0.51–0.58 mm long body, 5.5–6.0 μm long odontostyle, odontophore with minute basal knobs, pharyngeal bulb expanding gradually, female genital system mono-prodelphic and tail rounded to conoid with sunken terminus. Five known species of the genus Tylencholaimus viz. T. mirabilis, T. teres, T. micronanus, T. ibericus and T. cosmos also recorded from the region and redescribed/illustrated.

Two new species of Eutardigrada from Victoria Land, Antarctica

Two new species are recorded from Victoria Land (Antarctica): Mixibius felix sp. nov. and Milnesium validum sp. nov. A third species, Diphascon sanae Dastych, Ryan & Watkins, 1990, is a new report for this region of the Antarctic continent. Mixibius felix sp. nov. has a smooth cuticle, eyes present, bucco-pharyngeal apparatus of the Mixibius type (rigid buccal tube without ventral lamina and with hook-shaped asymmetrical apophyses for the insertion of the stylet muscles); stylet supports inserted on the buccal tube at 65.7–68.0% of its length; pharyngeal bulb with apophyses and two macroplacoids; microplacoid and septulum absent; as is characteristic of the genus, the external claws are of Isohypsibius type and the internal are a modified Isohypsibius type. Milnesium validum sp. nov. has smooth cuticle; eye spots present; six triangular peribuccal lamellae with basal stripes; stylet supports inserted on the cylindrical buccal tube at 61.1–64.8% of its length; claw configuration [3-3]-[3-3] (i.e. all secondary claws with three points); secondary claws stout, with distal portion clearly wider than the basal portion and each with a rounded basal thickening (lunule); primary claws with accessory points; a long cuticular bar present under claws I–III. Adding the three above mentioned species, the list of species present in Victoria Land rises from 12 to 15; 11 of these are recorded exclusively to this region of the Antarctic continent.

Effect of Root-promoting Products in the Propagation of Organic Olive (Olea europaea L. cv. Cornicabra) Nursery Plants

Olive cuttings root well using synthetic auxin indole-3-butyric acid (IBA). However, European and North American regulations do not allow the use of synthetic products to obtain organic vegetative propagation materials. In this work, we evaluated different products that could replace IBA in the propagation of olive cv. Cornicabra leafy-stem cuttings. In 2003, six products with a known auxin effect were assessed: IBA, algae extract, brewer's yeast, a bed of sunflower seed, seaweed dry extract (Sm-6 Organico™), and an extract of macerated seeds (Terrabal Organico™). The basal end of cuttings was treated with one of these products and placed on a mist bed with basal temperature control. After 2 months, rooting percentage, number of roots per cutting, number of cuttings with callus formation, and number of cuttings with basal thickening were determined. No significant differences were found in rooting percentage or number of roots per cutting between IBA and Terrabal Organico™ and Sm-6 Organico™. These last products had significantly higher percentage of rooted cuttings without callus formation than IBA. In 2004, a new trial was conducted in which seven treatments were evaluated: IBA applied for 7 s; Terrabal Organico™ applied for 1, 4, and 8 h; and Sm-6 Organico™ applied for 1, 4, and 8 h. No significant differences in rooting percentage or number of roots per cutting were observed between IBA and Terrabal Organico™ applied for 1 h, whereas all the Sm-6 Organico™ treatments had significantly lower rooting percentages than IBA. Both rooting percentage and the percentage of rooted cuttings without callus development decreased significantly as treatment duration with Terrabal Organico™ increased. Therefore, Terrabal Organico™ could produce a toxic effect on cuttings when treatment duration is increased. Thus, Terrabal Organico™ could be a valid alternative to IBA in the propagation of organic olive plants of cv. Cornicabra when applied to the basal end of cuttings for 1 h.

On the influence of vibrations upon the form of certain sponge-spicules

It has been pointed out recently* by one of us that the development of the remarkable chessman-spicule or discorhabd in the genus Latrunculia is a somewhat complicated process depending upon several factors. The protorhabd or axial thread appears first as a slender rod capable of independent growth. With these protorhabds two kinds of silica-secreting cells appear to be associated, viz., formative cells which are responsible for the actual deposition of the silica upon the protorhabd, and accessory silicoblasts which are supposed to collect supplies of silica and bring them to the formative cells to be used in the process of spicule-formation. The spicule in this case consists of an elongated axis with whorls of flattened lobes arranged at more or less definite intervals along its length, and it was suggested that the position of these whorls is determined by the fact that the spicule, at the time of their commencement, is in a state of vibration, due to the water currents flowing through the sponge, the whorls corresponding to the nodes or positions of comparative rest. The special accumulation of silica on the nodes appears to be due, not directly to the vibrations of the spicule, but to the fact that the formative cells exhibit a kind of tropism which induces them to settle down and perform their work in the positions where they are least disturbed by the vibrations. The whorls in this case are not sharply defined at the moment of their first appearance, so that it is impossible to obtain accurate measurements for mathematical analysis ; nevertheless, there are certain facts connected with their arrangement which, in our opinion, afford a fairly conclusive demonstration of the view that they are deposited approximately upon the nodes of a vibrating rod. Two species were investigated, Latrunculia apicalis and L. bocagei . In both species the spicule, at a certain stage of its development, consists of a straight rod with four thickenings, representing a basal manubrium and three incipient whorls. There is a basal thickening at one end, an apical thickening at the other, a median thickening at or near the centre, and a subsidiary thickening, usually between the median and apical thickenings, but occasionally between the median and basal thickenings. If these thickenings correspond to nodes, we have to account for the fact that a subsidiary thickening is developed only on one side of the median thickening. The solution of this difficulty is to be found in the arrangement of the formative cells (observed in Latrunculia bocagei only, though doubtless occurring in the other species also), for while there is a ring of formative cells round the median thickening and a similar ring round the subsidiary thickening, there is none around the part of the spicule where a second subsidiary thickening might be looked for, and hence no whorl is developed in this situation, in spite of its being a nodal point. No formative cells have yet been observed in relation to the basal and apical thickenings.