Theory suggests that micropredators can be virulent and that they will impact smaller hosts more than larger ones. We examined the interactions between micropredatory gnathiid isopods and juvenile damselfish Acanthochromis polyacanthus, the only fish on the Great Barrier Reef without a pelagic larval stage. Compared to most other fishes, A. polyacanthus can potentially interact with reef-based ...

The development of feeding morphology, kinematics and behavior was examined in the juveniles of the cottid fish Clinocottus analis. The attacks of 18 juvenile C. analis, between 17.59 mm and 42.15 mm in standard length (SL), feeding on brown worms were filmed using high-speed video. Feeding mode, ram- or suction-dominated, kinematic variables and morphology were quantified and compared over the...

The impact of Meloidogyne hapla on alfalfa (Medicago sativa) yield was described by a multiple point damage model as a function of current plant status, cumulative pest stress, and crop history. Nematode-degree days (NDD(female symbol)), calculated on a physiologic time scale as total area under the adult female population density curve, were used to express M. hapla parasitism as cumulative ne...

Four-week-old French Colombard plants rooted from green cuttings were inoculated with 0, 1,000, 2,000, 4,000, or 8,000 Meloidogyne incognita second-stage juveniles and maintained at 25 C night and 30 C day. Leaf area and dry weight and the rates of photosynthesis, stomatal conductance, and internal leaf CO concentration were measured at intervals up to 59 days after inoculation. Nematode stress...

Four-week-old French Colombard plants rooted from green cuttings were inoculated with 0, 1,000, 2,000, 4,000, or 8,000 Meloidogyne incognita second-stage juveniles and maintained at 25 C night and 30 C day. Leaf area and dry weight and the rates of photosynthesis, stomatal conductance, and internal leaf COs concentrat ion were measured at intervals up to 59 days after inoculation. Nematode stre...

One of the reasons for the progressive yield decline observed in cereals production is the rapid build-up of populations of the cereal cyst nematode (CCN, Heterodera avenae). These nematodes secrete so-call effectors into their host plant to suppress the plant defense responses, alter plant signaling pathways and then induce the formation of syncytium after infection. However, little is known a...

On a few occasions, soybeans with broken root tips were included in tests to evaluate resistance to Heterodera glycines. Although females developed on these plants, the numbers tended to be lower than on similarly treated intact roots. To test the possibility that removal of the root meristem affected nematode development, a culture system using pruned soybeans was devised that permitted access...

Pasteuria penetrans Sayre & Starr parasitizes several nematode species and is considered a promising biocontrol agent of the root-knot nematode, Meloidogyne spp. (1,7). Numerous plant-parasitic nematodes, including Tylenchulus semipenetrans, however, are seldom if ever infected by this biocontrol agent (3). Tylenchulus semipenetrans Cobb is the most economically important and widespread nematod...

Occurrence and level of hydrolytic enzymatic activity (proteases, glycosidases, phosphatases, lipases, and esterases) were studied in oocytes, larvae, juveniles, and adult haemolymph of the Pacific oyster Crassostrea gigas. Samples were obtained as oocyte lysate supernatant, larval homogenate supernatant, juvenile homogenate supernatant, haemocyte lysate supernatant, and plasma. The presence of...

Selective mortality during the early life stages in marine organisms can affect the magnitude and composition of recruitment, yet these processes have not been examined in economically important predatory coral reef fishes. Utilizing 3 different stage-specific sampling techniques (shipboard plankton tows, larval light traps, juvenile surveys/seines), we repeatedly sampled multiple cohorts of 3 ...