M. S. Jairajpuri

Predatory Abilities of Mononchoides Longicaudatus and M. Fortidens (Nematoda: Diplogasterida) and Factors Influencing Predation

Die rauberischen Fahigkeiten von Mononchoides longicaudatus und Mononchoides fortidens (Nematoda : Diplogasterida) und Faktoren, die das Beutemachen beeinflussen In in vitro Studien wurden die rauberischen Fahigkeiten aller Entwicklungsstadien von Mononchoides longicaudatus und M. fortidens untersucht, einschlieslich Beutefang, Mechanismus der Nahrungsaufnahme, Umfang des Beutemachens bei Adulten und Juvenilen, Beutebevorzugung sowie der Einflus der Anzahl Beutetiere, des Hungers der Rauber und der Temperatur auf das Beutemachen. Die Mechanismen des Beutefangs und der Nahrungsaufnahme werden in funf Phasen eingeteilt: Begegnung mit der Beute, Angriffsreaktion, Angriff, Speichelabgabe/extrakorporale Verdauung und Nahrungsaufnahme. Die meisten Phasen waren bei beiden Raubern vergleichbar. M. fortidens fing haufiger und brauchte weniger Zeit zum Verzehr der Beute als M. longicaudatus. Letzterer prufte seine Beute sanfter und fur langere Zeit, wahrend die Prufung von M. fortidens heftiger und kurzer war. Die Rate des Beutemachens blieb bei mannlichen und weiblichen Raubern uber zwolf Tage hinweg gleich. Sie wurde durch die Anzahl der vorhandenen Beutetiere, den Hungerzustand der Rauber und die Temperatur gesteuert. Der hochste Beutefang fand in einer Population von 200 Beutetieren bei 25-30°C mit Raubern statt, die 12 Tage gehungert hatten. Acrobeloides sp., Cephalobus sp., Panagrellus redivivus und die J2-Stadien von Meloidogyne incognita und Anguina tritici wurden von den beiden Raubern am starksten bevorzugt. Hoplolaimus indicus und Hemicriconemoides mangiferae wurden nicht gefressen.

Observations On the Predation Ability of Aporcelaimell Us Nivalis (Altherr, 1952) Heyns, 1966 (Nematoda: Dorylaimida)

Predation by Aporcelaimellus nivalis depended largely on chance encounters with the prey but the pre-feeding attraction and aggregation of up to 7 predators around an already injured prey at a feeding site is an indication of positive perception of prey body fluids. Prey catching and feeding mechanisms comprised five distinct phases viz., encounter with prey, attack response, attack, salivation/extra-corporeal digestion and ingestion/feeding. Rate of predation remained unchanged over a period of eight days but prey number, temperature, agar concentrations, starvation of the predators, type of the prey etc., determined predation. A. nivalis preferred second stage juveniles of Meloidogyne incognita (Kofoid & White, 1919) Chitwood, 1949 and Heterodera mothi Khan & Husain, 1965 to other species of prey nematodes. No predation took place when Hoplolaimus indicus Sher, 1963, Helicotylenchus indicus Siddiqi, 1963 and Hemicycliophora sp. were used as prey; thick cuticle, body annulations and toxic or unfavourable prey secretions were considered the likely cause. Adult (male and female) A. nivalis killing maximum number of prey nematodes was the most active predator stage.

The life cycle of Mononchoides fortidens (Nematoda: Diplogasteroidea) with emphasis on gonad development.

Mononchoides fortidens reproduced by amphimixis. Smooth, elongate eggs measuring 60-80 x 35-45 μm were laid in single-cell stage. Embryonic and post-embryonic development lasted for 16-20 h and 3-6 days respectively. Sexes were first distinguished during second moulting by the anterior elongation of primordium in males and anterior as well as posterior elongation in females. The aggregation of cells dorsal to the rectum in males represented the site of spicule formation. In females specialized ventral chord nuclei on the mid-ventral side of genital primordium formed the vagina. A flexure developed first in the third stage male, and later in fourth stage females. The life cycle from egg to adult was completed in 4-7 days.

Three New Species of Hemicycliophora De Man, 1921 From India

Three new species of Hemicycliophora are described and illustrated. Hemicycliophora altapadii sp.n. is characterized by its relatively large body size; conoid lip region with three annules, indented dorsovcntrally; a rectangular oral disc; elongated vulval lips; absence of longitudinal lines and R>370. H. meghalayaensis sp.n. also has a relatively large body; low flat lip region with three annules, first lip annule dorsoventrally indented; oral disc rectangular with central oval part surrounded by narrow collar; elongated vulval lips; absence of longitudinal lines and R=295-340. H. postamphidia sp.n. has a moderately large body; a conoid lip region with three lip annulcs, amphidial apertures covered by lateral shields and located away from oral disc; vulval lips three annules long; tail elongate conoid, then spicate with finely rounded terminus, R=340-372.

Studies on the genus Proleptonchus Lordello, 1955 (Dorylaimoidea: Leptonchidae) with description of two new species from India.

An emended diagnosis of the genus Proleptonchus Lordello, 1955 is proposed and two new species and the type species, P. aestivus are reported from India. Proleptonchus amphidius n. sp., is distinctive in having bell-shaped amphids, five ventromedian supplements, 32 μ long spicules and posterior uterine sac five times the body width long. Proleptonchus teres n. sp., has a small body size, cup-shaped amphids, four ventromedian supplements, 22 μ long spicules and posterior uterine sac two and a half times the body width long.

Loofilaimus, a remarkable new genus of Dorylaimida from Iran

Loofilaimus, a remarkable new genus of dorylaim nematodes is described from Iran. It is characterized by a continuous lip region with amalgamated lips; sclerotized cheilostome forming a bowl-shaped cavity, odontostyle short and wide, oesophagus conspicuously muscular along its entire length, amphidelphic gonads and short hemispheroid tails in both sexes. A new Family Loofilaimidae is proposed under Superfamily Tylencholaimoidea to accommodate this genus which has a curious mixture of characters of different dorylaim groups.

Five new species of mononchs from Malnad tracts of Karnataka, India

Five new species of mononchs, two of Cobbonchus, two of Iotonchus and one Parahadronchus, are described and illustrated. Cobbonchus inclinatus sp. n. is distinct in the presence of inclined vulva and absence of vulval papillae. C. papillatus sp. n. has 3-4 pre- and post-vulval papillae; males with 41-52 μm long spicules and 7 ventromedian supplements. Iotonchus apapillatus sp. n. is a large nematode with amphidelphic gonads, highly muscular and atypical vagina, terminal spinneret; males with massive spicules and 17-19 ventromedian supplements. I. southi sp. n. has mono-prodelphic gonads, advulval papillae, subterminal spinneret; males with medium-sized spicules and 12 ventromedian supplements. Parahadronchus magnus sp. n. is distinct in having a larger body of about 4-5 mm, barrel-shaped buccal cavity, atypical vagina; amphidelphic gonads; males with massive spicules and 15-16 ventromedian supplements.

Description of Criconemoides Chamoliensis N. Sp. and Observations On Mesocriconema Paronostris From India

Criconemoides chamoliensis n. sp. is characterized by 54-65 ornamented body annules, absence of submedian lobes, enlarged pseudolips connected laterally, stylet 64-75 μm long and acutely conoid tail. Mesocriconema paronostris (Deswal & Bajaj, 1987) is redescribed with SEM illustrations.