The Chaoborus (Diptera: Chaoboridae) component of the invertebrate drift of the Mwenda river,Lake Kariba,Central Africa

Chaoborus larvae were collected from the riverine drift of the Mwenda River during the 1972/3 rainy season. Large numbers of larvae were found in the early stages of flow following the 1972 dry season, fewer were found ten days later.Larvae which reached the lake in this way appeared to show no ill effects. Possible mortality arising prior to reaching the sampling point was doubtful since no dead larvae or parts were found in the material collected.     

Bacteriological Assessment of Spoon River Water Quality

Data from a study of five stations on the Spoon River, Ill., during June 1971 through May 1973 were analyzed for compliance with Illinois Pollution Control Board's water quality standards of a geometric mean limitation of 200 fecal coliforms per 100 ml. This bacterial limit was achieved about 20% of the time during June 1971 through May 1972, and was never achieved during June 1972 through May 1973. Ratios of fecal coliform to total coliform are presented. By using fecal coliform-to-fecal streptococcus ratios to sort out fecal pollution origins, it was evident that a concern must be expressed not only for municipal wastewater effluents to the receiving stream, but also for nonpoint sources of pollution in assessing the bacterial quality of a stream.     

Further study on seasonal fluctuations of Egyptian soil fungi

The seasonal fluctuations of fungi were studied in 72 soil samples collected at 10-day intervals between January 1972 and December 1973. The richest periods in the fungal population were January, March and September–December 1972, and April, May, September, November and December 1973. The poorest months were consistently June and July of 1972 and 1973 and August 1973 which are all summer months. Thirty-nine genera were isolated of which Aspergillus, Penicillium, Fusarium, Mucor, Rhizopus and Humicola were of high seasonal occurrence. Seven genera were of moderate occurrence and these were Cochliobolus,Stachybotrys, Paecilomyces, Cunninghamella, Myrothecium, Chaetomium and Sepedonium. The remaining genera were of low or rare seasonal occurrence. Aspergillus showed its highest prevalence during the periods May-September 1972 and April-August 1973. Twenty-four species of Aspergillus in addition to two varieties of A. nidulans were isolated, of which A. niger, A. fumigatus, A. terreus, A. nidulans and A. sydowii were dominant. Thirty species of Penicillium were identified, of which P. notatum, P. funiculosum and P. chrysogenum were of high seasonal occurrence. Penicillium predominated during winter and spring months. Fusarium showed its highest percentage populations during the periods February, March, April, October, November and December 1972 and February, August, September, October and November 1973. Four species of Mucor were recorded of which M. racemosus was the commonest; and its highest percentage populations were recorded in November 1972; and February, March and November 1973 which are moderate temperature months. Rhizopus was represented by two species of which R. nigricans was of high seasonal occurrence. Three species of Humicola were isolated of which H. grisea was the most common.     

The numbers, biomass and transport downstream of micro-crustaceans and Hydra from Cow Green Reservoir (Upper Teesdale)

Fluctuations in numbers and biomass of Copepoda, Cladocera and Hydra drifting out of the Cow Green reservoir via the outflow were investigated during the period August 1972-November 1973. Cladocera, chiefly Daphnia hyalina var. lacustris Sars and Copepoda, were most abundant between July and September, occurring at mean densities of 1278 and 215 m^?3 respectively. Hydra was most abundant between August and October at a mean density of 19 m^?3. Winter densities of all groups were low and 98% of the total annual output occurred between July and October. An estimated 150 kg (136 kg of Cladocera, 13kg of Copepoda and 1 kg of Hydra) dry weight was released from the reservoir during the year November 1972-October 1973. During periods of peak abundance about 1–2% of the total fauna drifting out of the reservoir was found 6·5 km below the dam. The effect of reservoir discharge and flow in tributaries of the Tees on this transport downstream is discussed. It is suggested that the micro-crustaceans and Hydra, even if not fed upon directly, will have considerable influence on the Tees benthos when they settle out and decompose to produce a nutrient-rich detritus.     

Isolation of parahemolytic vibrions from persons with acute gastrointestinal diseases]

Galophilic vibrios were for the first time in the Soviet Union isolated from the patients with gastrointestinal diseases in Novorossiisk during the summer-autumn period of 1973. The greatest number of strains of the parahemolytic vibrios was isolated in August and September, during intensive fishing season, from the patients in whom the disease usually developed 6 to 12 hours after eating the sea fish. The parahemolytic vibrios isolated from the patients were typical by all signs and produced a marked hemolysis on the Wagatsuma medium. The halophilic vibrios are inhabitants of the Black Sea. During the years of 1972-1973 there were isolated 109 strains of V. paraheamolyticus and 133 strains of V. alginolyticus from the sea water and various hydrobionts.     

AUTUMN MIGRATION OF QUAIL COTURNIX COTURNIX AT THE NORTH COAST OF THE SINAI PENINSULA

Autumn migration of Quail was studied on the northern coast of Sinai in 1972 and 1973. Arab Quail nets were used to catch totals of 4863 and 1823 in the two years, respectively. Of 1761 Quail ringed in 1973, 0–4% have been recovered from the extensive area predicted by earlier ringing results. Quail started to enter nets 10 min after first light, and continued to do so until 0800–0900 h, local time. The quantity netted per day varied greatly, producing waves of migration which were inversely correlated with the barometric pressure over Europe prior to the arrival of each wave. Each of the arriving waves was apparently a discrete (group of) populations) from one area. The very close similarities in the arrival dates of each wave for both the 1972 and 1973 passages has been interpreted as showing that the timing of autumn migration in Quail is mainly dependent on exteroreceptive time–setters and/or biological clocks. Sex and age ratios of each day's catch varied greatly and were related to the rise and fall in numbers of Quail arriving each day. The approximate sex and age ratios for all Quail crossing the coast after dawn during the 1973 passage was 58% male, 75% young, and 7–2 young per adult female. The 26 Quail analysed for fat and water content were definitely not suffering from dehydration, but many of them would not have been able to reach their wintering grounds without additional food. The ‘average’ Quail had 75% of the fat reserves required, while less than 20% of the Quail had the required amount. The daily temporal pattern of netting suggests that a proportion of the Quail cross the coast before dawn and alight at dawn well dispersed within the Sinai desert. This, together with the observed inverse correlation between the amount of fat at arrival and the time of netting, suggest that it is the Quail in poorer physiological condition that arrive later in the day, and that these may stand smaller chances of completing their autumn migration even if not netted by man. More than three times the number of Quail were caught per metre net in 1972 than 1973 (2–43 Quail/metre net/season and 0–73 Quail/metre net/season, respectively. This decline cannot be attributed to hunting. Rough quantitative data during the years 1900–1959 shows that the abundance of Quail in any year was not dependent on abundance in the preceding year. On the other hand, fluctuations in Quail abundance were associated with long–term climatic changes, i.e., netting success in Egypt was negatively associated with rainfall in the Sahel, and shooting in Luxembourg was positively correlated with temperatures in Germany.     

Life History of Ilybius fenestratus (Fabricius) (Coleoptera,Dytiscidae) in a Central Norwegian Lake

The life history of Ilybius fenestratus was studied in Målsj?en, a lake in S?r-Tr?ndelag, Central Norway (63°14'N, 10°26'E), during 1971–1972. Adults and larvae were sampled in activity traps every week during March–October and every 2–3 weeks during November–February. Newly-emerged adults were generally found from mid-July to September, and after overwintering in torpidity, probably in the water, they again appeared in the second half of June to August/September. Laying of eggs took place from early/mid July to early August. Larvae occurred in the traps from late July to early May. I. fenestratus was thus found to be a semivoltine summer breeder, with overwintering larvae the first winter and overwintering adults the next. Both adults and larvae lived in large areas of the lake's littoral zone.     

Trichomonas gallinae in columbiform birds from the Galapagos Islands

Domestic pigeons were introduced into the Galapagos Islands in 1972 or 1973. There is a high prevalence of Trichomonas gallinae among them and some evidence of canker. Trichomonas gallinae can be found also in endemic Galapagos doves in the vicinity of Puerto Ayora on Santa Cruz Island. Doves examined on pigeon-free islands were not found infected.     

'Siamese-twins' in Sarotherodon mossambicus

Tilapia mossambica (Sarotherodon mossambicus (Trewavas, 1973)) a female mouthbreeding cichlid, Fryer & Iles (1972), has recently been introduced to the Fish and Aquaculture Research Station, Dor, from South Africa. They were found to spawn freely in aquaria. Females carrying eggs in their mouth are routinely transferred to small containers, and when the fry are released they are separated from their mothers.
In one batch of 209 fry we found two fry connected at their ventral part to the same yolk sack. These' Siamese-twins' survived for 8 days in an aerated glass jar. During this period the yolk sack was absorbed and they became connected at their abdomens. (Plate I). Similar cases were previously noted in sharks, trout, Salmonidae spp., guppy, Poecilia sp. and Haplochromis sp. (Reichenbach-Klinke & Elkan (1972) and Reichenbach-Klinke (1972)).     

Seasonal and year-to-year differences in food selection by beavers

Summary Selection of trees for food by a colony of beavers in central Massachusetts was studied from September 1972 through April 1974. The beavers exhibited both seasonal and year-to-year differences in preference for certain genera. Pine was selected against during fall but not spring, and there was a switch in preference from birch during fall 1972 to oak and witch hazel in fall 1973. These differences may partly reflect greater seasonal stability in concentrations of stored nutrients in coniferous tree bark than in deciduous tree bark, and greater year-to-year stability in bark concentrations of stored nutrients in non-mast-seeding species than in mast-seeding species (1972 was a mast year for oaks in central Massachusetts).     

The biology of the ground beetle Harpalus rufipes in a strawberry field in Northumberland

Harpalus rufipes (Degeer) was studied in a strawberry plot in Northumberland from 1973 to 1978 by pitfall trapping, and in the laboratory. Adults were active from April until November. Overwintered male beetles predominated at the beginning of each season until May, followed by overwintered females in June and July. Newly emerged, mainly female, beetles were active from August onwards. Overwintered females matured during early summer and laid eggs in August with a fecundity of 10–15 eggs/female. In the laboratory about 30% of beetles survived from one breeding season to the next. First- and second-instar larvae were caught in pitfall traps in autumn; in the laboratory they made approximately vertical burrows in which they stored seeds taken from the soil surface. Third-instar larvae fed on these seeds and were not active on the surface. Preferred seeds were those of grasses and Chenopodium album L. Larvae were usually aggregated in the soil at densities of 3–20/m².     

Earthworm numbers,biomass and respiratory metabolism in a beech woodland-Wytham Woods,Oxford

Summary The mean annual population density of earthworms was found to be 164.6 m^-2 during a period of detailed study between October 1971 and September 1972. In a year of less detailed study between November 1972 and October 1973 the population density was 117.5 m^-2 (139.8 m^-2 when the type of extraction method was allowed for). Mean biomass densities in the two years of investigation were 41.0 g preserved wet wt m^-2 (1971–1972) and 38.6 (possibly 39.2) g preserved wet wt m^-2 (1972–1973).Comparison of the Brogden's Belt population and biomass densities with those reported from other woodlands indicates that soil type is more important than leaf litter type in determining the numerical abundance of earthworms. Population densities are lower in beechwoods on mor soils, mor soils also support significantly fewer species. As with numbers, mean biomass density in beechwoods on mor soils was significantly lower than that occurring in beechwoods on mull soils; the latter, in turn, being lower than those found in mixed deciduous woods on mull soils. Unlike population density biomass density is influenced by both soil and litter type, this is discussed by reference to mean body weights and food quality as reflected by tannin, nitrogen and carbohydrate content.The annual respiratory metabolism of the Brogden's Belt earthworms was calculated to be between 10.7 and 13.41 O₂ m^-2 a^-1, which is equivalent to between 4.1 and 5.1% of the total soil metabolism. A production/biomass ratio of 0.49–0.58 was estimated, as was a net population efficiency of 22%.     

Incidence of resistance to ampicillin,chloramphenicol, kanamycin and tetracycline amongSalmonella species isolated in The Netherlands in 1972, 1973 and 1974

The resistance ofSalmonellae to drugs has been studied in the Netherlands since 1958. In 1972, 1973, and 1974 respectively, 14241, 13086, and 22927 strains were tested for resistance to ampicillin, chloramphenicol, kanamyci and tetracycline. From 1973 all strains were also tested for resistance to trimethoprim. In the period covered, the yearly incidence of resistance to at least one of the above drugs ranged from 39.2% to 45.6% of all strains obtained from various sources (humans, animals, animal products, sewage, etc.). A new finding in the period 1972 to 1974 was that many multiply resistant strains emerged inS. typhimurium and inS. dublin isolated from calves and cattle. In 1974, 64.4% of all strains ofS. typhimurium from these animals appeared to be resistant to ampicillin, tetracycline, chloramphenicol and kanamycin, and 25.5% of those ofS. dublin were found to be resistant to chloramphenicol and tetracycline. Of all strains ofSalmonellae examined in 1973 and 1974 respectively, 0.15 and 0.22% were resistant to trimethoprim, the main component of the twin-drug cotrimoxazol. Of the 142 strains ofS. typhi isolated in 1972 to 1974 two were resistant to tetracycline only, and one was resistant to all four antibiotics. The others had a normal susceptibility pattern.     

EDITORIAL

Olver, M. D. &; Kuyper, M. A. 1978. Breeding biology of the Whitebreasted Cormorant in Natal. Ostrich 49:25-30.

From 1972–1975 Whitebreasted Cormorants Phalacrocorax carbo bred at the Cedara Dam, Natal, South Africa (29 32S, 30 17E), and from 1973 they fished for food at Midmar Dam, 5 km away and carried the food back to the nestlings. Breeding occurred from April to October and was preceded by a period of courtship. Nesting material was collected by the males and the nests built by the females. The mean clutch size for 1972–1973 was 3,1. Both parents incubated the eggs and guarded the nest and chicks. Growth of the chicks was studied in 1972–1973. The mean number of chicks reared was 1,6 per nest although seven nests contained three nestlings. At 28 days they left the nest when alarmed, but could not fly until 49 days old. The average flying age appeared to be about 53 days. The height of the nests above the ground seemed to determine the nest leaving age. Of the 186 eggs laid in the 60 nests observed over two years, 74% hatched. Fledging success was 52% of eggs laid and 69% of eggs hatched. Chick mortality seemed to be caused mainly by falling from the nests and dying of starvation.     

Larval development of the cockle Chione stutchburyi (Bivalvia: Veneridae) reared in the laboratory

Abstract

Larvae of the New Zealand cockle Chione stutchburyi (Wood, 1828) reared to settlement in the laboratory are described. They are characterised by dissimilar shoulders with a large, broadly rounded anterior shoulder and end, and broadly rounded umbo, typical of the Veneridae. Setting occurred after 20 days at a minimum length of 180/µm. Shell dimensions increased linearly during larval development but hinge length did not. The L:H ratio decreased from 1.27 at L = 100 to 1.1 at L = 200 and the L:D ratio from 1.95 at L = 100 to 1.59 at L = 200. An SEM study revealed that the larval hinge is characterised by a toothed provinculum forming a broad medial projection on the right valve, opposing two projections on the left valve. Conspicuous flanges on the anterior and posterior shoulders of the left valve fit into corresponding grooves of the right valve.     

Sea trout in North Argyll sea lochs: II. diet

The diet of sea trout in some of the sea lochs of the west coast of Scotland was investigated. The contents of 986 sea trout stomachs from the Loch Etive area (1970–1973), and 291 stomachs from the Loch Eil area (1964–1973), were examined and the composition of the diet, seasonal changes and the effect of trout size were analysed using frequency of occurrence, dry weight and number of organisms methods. Benthic feeding (crustacea and annelids) was more important in winter while midwater and surface organisms (young fish and insects) were preferred in summer. Young fish (mainly clupeids and sand eels) featured more in the diet of larger trout (≤21 cm) than in the smaller size range (≥21 cm). Surveys of 24-h were completed in June and September, 1972, and indicated that availability of food was the main factor influencing the presence or absence of trout. Bottom feeding was greatest during the day while the amount of midwater and surface feeding tended to increase between sunset and sunrise.     

Extremely low frequency antenna operation: tests for possible impact on five naturally exposed animal populations

Wood lice, Oniscus asellus, earthworms, Lumbricus terrestris and Lumbricus rubellus, slugs, Arion sp., and red-backed salamanders, Plethodon cinereus cinereus, were collected under the Sanguine test facility antenna during summer 1972 and 1973 and their O₂ consumption and RQ were compared with controls collected on the same day, 6–13 miles from the nearest antenna. In 1972 there were no significant differences in O₂ consumption in four groups of test and control animals and marginal significance (P < 0.05) in wood lice; there were no significant differences in RQ of any group. In 1973, there were no significant differences in the O₂ consumption and RQ of all five groups.     

Hemoparasites of raccoons (Procyon lotor) in Florida

Four hemoparasite species (Babesia lotori, Trypanosoma cruzi, Dirofilaria tenuis and Mansonella llewellyni) were found in raccoons (Procyon lotor) collected from 1972 to 1974 in Duval (n = 14) and Collier (n = 170) counties, Florida (USA). Trypanosoma cruzi was found in thin blood smears from one raccoon at each locality. The prevalence of B. lotori was 79% and 80% in samples taken in December 1973 in Collier and Duval counties, respectively. No patent infections by B. lotori were detected in raccoons collected in Collier County in December 1972, but 42% of the raccoons examined in September 1973 were infected. In Collier County there were no significant differences in the prevalence of B. lotori by host sex or age. In Duval County, overall D. tenuis prevalence was 7%, whereas that of M. llewellyni was 14%; the latter species was not found in Collier County. Adult raccoons had a significantly greater prevalence of D. tenuis (32%) than did subadults and juveniles (7%), and male raccoons showed a significantly greater prevalence (51%) than did females (8%).     

The occurrence and natural alleviation of stunting in a population of roach, Rutilus rutilus (L.)

Two sudden and pronounced changes in the growth rate of roach, Rutilus rutilus (L.), in Slapton Ley, Devon, have been observed between 1972 and 1976. At first the growth rate declined to the point at which the population became stunted, then subsequently it improved again. These changes were correlated with population density; the numbers of roach were increasing during the late 1960's/early 1970's, and this increase was substantially reinforced by very strong year classes in 1972, and, to a lesser extent, in 1973. The increase in population density resulting from the strong 1972 year class was apparently adequate to accelerate the onset of the stunting observed. The improvement in growth rate in 1976 followed immediately after extensive mortalities amongst the roach during 1975, caused by an epidemic of the parasite Ligula intestinal is (L.). Some improvement in the growth of O group roach had been evident during 1975, but this was not observed in the population. Ford-Walford plots showed a decline in the value of L after the onset of stunting in 1972.
Differences in the reproductive biology of the fish were found following the alleviation of stunting; the gonads of both sexes achieved a greater relative weight, and correspondingly the fecundity of the females was higher, although this latter effect became progressively less marked with increasing size. It was not apparent amongst the largest individuals. There was also some evidence of a decline in the proportion of fish maturing at minimum size. The changes in the reproductive biology were associated with the improvement in conditions for individual fish following the decline in population density.     

Serological evidence of inter-epidemic infection of feral pigs in New South Wales with Murray Valley encephalitis virus.

The sera of 617 feral pigs, collected from three widely separated areas of northern and central New South Wales, were examined for antibody to Murray Valley encephalitis (MVE) virus and to Ross River virus. Haemagglutination-inhibition (HI) antibody was detected to MVE in 58% of sera and to Ross River virus in 15% of sera. Neutralization tests suggested that the MVE HI antibody resulted from infection with MVE virus in the summers of 1971-1972 and 1972-1973 when the virus was not known to be active in New South Wales. These same tests suggested that more than one flavivirus infected the feral pigs in the summer of 1973-1974 and that Kunjin virus was active in the summer of 1975-1976.