The relationship of Recent foraminifera to the sedimentary facies in the turbulent zone,Cardigan Bay

Summary

The behaviour and feeding habits of T. biguttatus, T. fraternus, T. taeniola. T. gratus and H. decora were studied in the vicinity of a resting cattle herd. The observations could be substantiated by experiments with flies on restrained animals and an examination of 11 189 Tabanidae in regard to presence and size of fresh blood meals.

By relating these findings to the principles of mechanical transmission, the small Tabanidae T. gratus and H. decora did not show the expected behaviour of potential vectors. Of the large species, T. biguttatus and T. fraternus did not qualify on the basis of their feeding habits. It was concluded that T. taeniola fulfilled, in regard to behaviour and feeding habits, all requirements for mechanical disease transmission under natural conditions.     

The occurrence of Parvatrema homoeotecnum James, 1964 (Trematoda: Gymnophallidae) in a population of Littorina saxatilis tenebrosa (Mont.)

Summary

Marking experiments, seasonal variations in the population density and observations on the breeding cycle indicated that healthy adult Littorina saxatilis tenebrosa (Mont.) migrate down to the lower supralittoral fringe in order to give birth to the young in July–August and in January–February. The young and adults then migrate up towards the upper supralittoral fringe. Specimens infected with Parvatrema homoeotecnum, unlike those infected with two other digenean species investigated, migrate in the same way as healthy specimens. This ensures that although initial infestation takes place in the lower supralittoral fringe, parasitized specimens occur throughout the supralittoral fringe. Only juvenile hosts, below 7·0 mm long and usually below 5·0 mm long are infected, highest percentages occurring in specimens measuring 1·1–2·0 mm long. The seasonal variations in percentage infection are corellated with the breeding cycle, growth, mortality and migration of the host.     

The fishes of Saint Helena Island,South Atlantic Ocean. II. The pelagic fishes

The pelagic fishes of St Helena Island, South Atlantic Ocean (15°58′S 5°43′W) are reviewed. A checklist of 53 taxa of pelagic fishes, with notes on fisheries significance, ecology and geographical distribution, is presented. Twelve of the taxa have not before been recorded at St Helena. Of particular interest are records of three primarily Indo-Pacific species: Decapterus muroadsi (Temminck and Schlegel), Uraspis helvola (Forster) and Scomberomorus commerson (Lacepède). Apart from U. helvola, which is known also from Ascension Island, these species are not otherwise recorded in the Atlantic Ocean.

Of the 49 pelagic fishes whose identities are clear, 81·6% are wide-ranging species known from both the Atlantic and Indo-Pacific regions, 12·2% are pan-Atlantic warm-water species and 4·1% are eastern Atlantic species which reach their western limit in the central Atlantic. In addition, the subspecies Platybelone argalus trachura is found only at St Helena and Ascension.

The principal pelagic species caught by St Helena fisheries are Katsuwonus pelamis, Thunnus albacares, T. obesus, T. alalunga, Scomber japonicus, Acanthocybium solandri and Pseudocaranx dentex, which together accounted for almost 95% of fish landings in 1982–1983 fiscal year.     

The sex ratios of Trichoniscus pusillus Brandt (Crustacea: Oniscoidea)

Summary

The frequency of males in the bisexual and parthenogenetic forms of T. pusillus is assumed to be 0·5 and 0·03 respectively. This assumption for the bisexual form is tested with culturing, which demonstrates a numerical equality of the sexes and produces no evidence of differential survivorship of the sexes, and by field sampling of a suspected bisexual population. A statistical technique using the difference in male frequency in the two forms to determine the composition of T. pusillus agg. is presented. Other work on sex ratio in isopods is reviewed.     

Planktonic copepod community of a reef zone in the southern Gulf of Mexico

ABSTRACT

In this study, the variation of seasonal and inter-annual density and diversity of the copepod community in the Parque Nacional Sistema Arrecifal Veracruzano (PNSAV) was analysed. Samples were collected under nortes, rainy and dry weather conditions in 2011, as well as under nortes and dry weather conditions in 2012 and 2013 in four transects. Surface trawls with 330-μm conical nets were made. The temperature, salinity and dissolved oxygen were measured in situ. The values obtained were 23.07 ± 0.53 to 29.29 ± 0.27°C for temperature, 33.43 ± 0.49 to 35.91 ± 0.09 for salinity, and 2.52 ± 0.08 to 6.56 ± 0.08 mg l^?1 for dissolved oxygen. The copepods collected belonged to 19 families, 28 genera and 62 species. Copepods represented between 69.74% and 76.79% of the abundance of crustaceans present in zooplankton. The highest number of copepods occurred under nortes weather conditions in 2011 with 401,885 ± 28,092 copepods/100 m³ of the species Temora stylifera. In 2012, 256,325 ± 76,872 copepods/100 m³ of the species Paracalanus aculeatus were obtained and in 2013, 311,526 ± 76,872 copepods/100 m³ of the species T. turbinata. The highest specific richness was found in the southern zone with 28 species. In 2013 the highest density was found in the northern zone with 100,323 ± 28,888 copepods/100 m³. The highest diversity was found under dry weather conditions in 2011 with 3.71 bits/individual. In the 3 years of study, 24 species were dominant; 12 of these, appeared in the 3 years of sampling: T. stylifera, T. turbinata, Labidocera scotti, P. aculeatus, O. latus, Pontellopsis villosa, Centropages velificatus, Parvocalanus crassirostris, Corycaeus speciosus, Undinula vulgaris, Oithona plumifera, and Farranula gracilis. Canonical correlation analysis showed the formation of five groups explained by the neritic or oceanic affinity of the species and their tolerance to changes in salinity or temperature.     

VI.—Revision of the species of Hyrax,founded on the specimens in the British Museum

Summary

Spirocamallanus olseni, previously known only from Madagascar in lutjanids and a remora, also infects the lutjanid, Lutjanus fulviflamma, in the Gulf of Elat; it becomes the second member of the genus reported from the Red Sea. Procamallanus elatensis sp. nov. from two siganid fishes becomes the second known Red Sea species in that genus, but appears most related to two other species from signaids. It can be characterized by having a distinct ledge in the buccal capsule anterior to the basal ring and an excretory pore anterior to the nerve ring. In the male, a gubernaculum and three pre-cloacal plus five post-cloacal papillae are present and the spicules have blunt tips with a crook and a ratio of 1:2·4 to 3·3. In the female, the vulva occurs 33 to 45% of the body length from the anterior end.     

Laboratory studies on the effect of crowding on phase and the life history of Schistocerca pallens (Thunberg) (Orthoptera: Acrididae: Cyrtacanthacridinae)

Summary

The life-history of Schistocerca pallens (Thunberg) has been studied under controlled laboratory conditions.

Both isolated and crowded stocks passed through six nymphal instars, with which the number of eye-stripes in the compound eye correspond.

The mean length of nymphal life of isolated individuals was 64·8 days for males and 67·1 days for females. Mean duration of nymphal life of individuals reared in crowds was 60·1 days irrespective of sex.

The mean time elapsing between the last ecdysis and the first oviposition for isolated females was 32·8 days. Each female laid an average of 6·36 egg-pods with an average of 57·8 days. Each female laid an average of 6·36 egg-pods with an average of 57·8 eggs por pod; of these 63·3% hatched.

Crowded females laid their first egg-pod on the seventeenth day. They laid an average of 14·44 egg-pods per female with a mean of 60·70 eggs per pod, of which 77·58% hatched. There was no significant difference in fecundity between females grown at the two rearing densities, but there was a great difference in fertility.

There was no difference in hatchling weight between the two rearing densities.

No significant chromatic or behavioural variations occurred in relation to isolation or crowding, but morphometrics showed differences associated with rearing density.     

Filth inhabiting flies of Dacca city

Summary

Information obtained about the association of various flies with different types of filth in Dacca city, their life histories, food preference of the larvae, and the seasonal changes of their population has been recorded.

The filth of Dacca city has been classified into the following eight categories for the present work. (1) Human excrement, (2) cow dung, (3) manure heaps, (4) garbage and kitchen refuse, (5) decaying fruits and vegetables, (6) carrion, (7) rotten fish and meat, and (8) municipal sewage and other liquid waste.

In total nine fixed areas in different parts of the city were visited regularly to collect adult flies, or their eggs or larvae.

The association of various flies with the above eight types of filth has been discussed.

The duration of the life cycle from oviposition to emergence of the adults was recorded for five species of Psychoda, seven species of Musca, one species of Calliphora, two species of Chrysomyia, two species of Lucilia, and three species of Sarcophaga, during summer and winter.

Food preferences of the larvae of two common species of Musca, two species of Sarcophaga, one species of Lucilia, one species of Calliphora, and two species of Chrysomyia have been recorded.

The trend of the seasonal variation of the various fly populations have been discussed.     

Laboratory rearing of the larval stages of Carcinus maenas (L.) [Crustacea: Decapoda]

Summary

Larvae of Carcinus have been reared to the crab stage for the first time in the laboratory. Artemia nauplii were successful as food from Stage II zoeae onwards and Stage I zoeae fed and moulted successfully on the dinoflagellate Prorocentrum. Animal foods smaller than Artemia were not tried, but the larvae or eggs of molluscs, echinoderms or polychaetes would probably be suitable. Entirely algal diets were unsatisfactory for complete development.

On diets of Prorocentrum and Artemia, the overall survival rates to first crab stage were about 30% and the average total development time was 57·7 days. Average duration of each larval stage, in days, was 14·8 (zoea I), 7·9 (zoea II), 9·6 (zoea III), 10·0 (zoea IV) and 15·4 (megalopa).     

Studies on the life cycle of the cicadellid bug Empoasca dolichi Paoli,in Southern Nigeria

Summary

Studies carried out on the biology of E. dolichi Paoli showed that its eggs are palegreen to creamy white, elongate and often curved, and have a mean length and width of 0·84 mm and 0·16 mm respectively. The egg-incubation period averaged 8·3 days under uncontrolled insectary conditions of 21–32°C and 45–95% relative humidity, while the life-cycle from egg to adult averaged 17·5 days. In the insectary, mating in E. dolichi usually started between the third and sixth day after adult emergence. Over 56% of observed individuals mated on the 4th day. The observed diurnal mating period was mainly within 05·30–09·00 hours and 16·00–20·00 hours local time, with an average copulation period of 65·7 min. The mean pre-oviposition period of 3·0 days for 23 mated females was significantly shorter than 4·0 days for 21 unmated females. An average of 116 eggs and 96 eggs were laid by mated and unmated females respectively, but the fecundity rate (3 eggs/day of total life-span) of mated females was significantly higher than that (2 eggs/day) of unmated females. Unmated females lived longer (mean=49·7 days) than mated females with a mean of 38·3 days. The average life-span for mated and unmated males was 31·0 and 32·4 days respectively. Insectary and field observations revealed that females of E. dolichi preferentially lay their eggs into the stems, leaf-veins and leaf petioles of cowpea plants. Only mated females of E. dolichi laid viable eggs, and the observed male: female sex-ratio of their progeny in the insectary was 1:1·04.     

Book reviews

Summary

Five early ontogenic stages of Scomberomorus lineolatus (C. &; V.) ranging in standard length from 18·4 mm to 99·5 mm are described.

Direct comparison of these early stages with those of S. commerson (Lac.) showed differences in the number of gill rakers, the length of preopercular spines and the position of the anal fin in relation to the second dorsal fin. In the case of S. guttatus (Bl. &; Schn.) the gill rakers are of the same number as in S. lineolatus but the preopercular spines decrease in size from above with the upper two subequal in size and none projects beyond the operculum.

In the earlier stages, S. lineolatus could be easily distinguished from S. guttatus by the absence of the bluish green coloration characteristic of S. guttatus. In later stages when the coloration has developed in both the species the only marked difference between the two is in the nature of the bent portion of the lateral line which is wavy in S. lineolatus and straight in S. guttatus.

The number of vertebrae is 46 in S. lineolatus; 42–45 with 43·9 as mean in S. commerson and 47–52 with 49·7 as mean in S. guttatus.     

On Schistosoma curassoni,S. haematobium and S. bovis from Senegal: development in Mesocricetus auratus,compatibility with species of Bulinus and their enzymes

A comparative study on the development of Senegalese isolates of Schistosoma curassoni, S. haematobium and S. bovis in hamsters is reported, together with the compatibility of these parasites with Bulinus spp. and enzymes of adult worms.

The mean worm return from 35 hamsters exposed to 100 cercariae each of S. curassoni was 11·5%, and of these 54% were paired, the remainder were single males. The growth and maturation of the worms were recorded from 40 to 100 days. The cross-over point (when paired females are of the same length as paired males) was reached at 42 days post-infection when the worms averaged 13·7 mm in length. The majority of tissue eggs (84·5%) were recovered from the liver, compared with 11% in the colon, 2·5% in the caecum and 1·6% in the small intestine. Estimates of the fecundity of paired females averaged 167 eggs/day per female worm. Snail-infection experiments showed S. curassoni to be compatible with B. umbilicatus, marginally compatible with B. senegalensis and incompatible with B. forskalii, B. jousseaumei and B. guernei. S. curassoni is marginally compatible with B. bavayi, B. beccarii, B. camerunensis and B. cernicus, (members of the B. forskalii group) and B. obtusispira, a species placed in the B. africanus group. The mean worm return from 35 hamsters exposed to 100 cercariae each of S. haematobium was 9·1%, and of these 46·7% were paired, 42·1% were single male worms and the remaining 11·2% were single female worms. The growth of the worms was recorded from 40 to 100 days, the maturation from 60 to 100 days. The cross-over point was reached at about 62 days post-infection when the worms averaged 8·3 mm long. The majority of tissue eggs (95·3%) was recovered from the liver, compared with 2·8% and 1·9% from the small intestine and colon, respectively. Estimates showed that the average fecundity of paired females was 86 eggs/day per female worm. Snail-infection experiments showed that S. haematobium is marginally compatible with B. senegalensis, but incompatible with B. guernei and B. forskalii. The mean worm return from 35 hamsters exposed to 100 cercariae each of S. bovis was 26·6%, and of these 53·1% were paired, the remainder were single males. The growth and maturation of worms were recorded from 40 to 100 days. The cross-over point was reached just before 40 days: at 40 days the paired males averaged 9·5 mm in length, the paired female 9·6 mm in length. The majority of eggs (53·1%) was recovered from the liver, compared with 20·7% from the small intestine and 19·8% from the colon.

Estimates of the fecundity of paired females averaged 95 eggs/day per female worm. Snail-infection experiments showed S. bovis to be compatible with B. guernei, fairly compatible with B. forskalii, and marginally compatible with B. umbilicatus. B. senegalensis appeared to be sensitive to S. bovis under laboratory conditions with large numbers dying after one week of exposure.

Enzymes in 3017 extracts of adult schistosomes, obtained from natural and laboratory infections, have been analysed by isoelectric focusing. Enzymes studied include glucose 6-phosphate dehydrogenase (G6PDH), phosphoglucomutase (PGM), lactate dehydrogenase (LDH), acid phosphatase (AcP), malate dehydrogenase (MDH), hexokinase (HK) and glucose phosphate isomerase (GPI). S. bovis was clearly differentiated from S. haematobium by patterns of G6PDH, GPI, HK and AcP. Similarly, S. bovis and S. curassoni were distinguishable by the different patterns of PGM, GPI, HK and AcP. S. haematobium and S. curassoni were differentiated by patterns of PGM and HK. Heterogeneity was seen in all species. In a natural infection of a sheep S. bovis and S. curassoni were found paired together.     

The armoured scale insects (Homoptera: Diaspididae) of avocado trees in Israel

Summary

Seven species of armoured scale insects infest avocado in Israel. Hemiberlesia lataniae (Signoret) and Abgrallaspis cyanophylli (Signoret) are the most abundant. Avocado seedlings become infested in the nurseries, thus serving as important sources for commercial grove contamination. Because larger diaspidid populations develop at the inside of the trees (as compared to their outside), and at height levels of 1·5–2·0 m (compared to 5·0–6·0 m), these regions were regularly sampled. Equal-area examinations of bark and leaf revealed that H. lataniae prefers the bark, A. cyanophylli the leaves. The populations of both scales undergo similar annual cycles on leaves, peaking during winter, ebbing in early summer. The specific settling pattern of most diaspidids on avocado leaves were figured. The somewhat-different settling sites of H. lataniae and A. cyanophylli apparently preclude competition when low numbers are present, but the former may be partially inhibited when large populations develop. Several predators and hymenopterous parasitoids attack the diaspidids, the parasitoids being most active in early summer. No economic injury to local avocado fruit by armoured scale insects has been reported in recent years. The reasons for this are discussed, and it is recommended that the present situation, in which no insecticides are used in avocado groves, be maintained.     

Mating behaviour in two closely related sympatric species of Philonthus (Coleoptera: Staphylinidae)

Summary

The intra-specific mating behaviour of two closely related sympatric staphylinid beetles, Philonthus cephalotes (Grav.) and P. sordidus (Grav.) is described in detail. Mating is essentially similar in the two species, although differing in the duration of copulation (1·7 min in cephalotes, 44·6 min in sordidus), and consists of four phases (A)-(D); (A) pre-copulatory phase, (1) examination of female abdominal apex by male, (2) examination of male abdominal apex by female, (3) prolonged examination of female by male, (4) mounting by male (5) extrusion of male genitalia; (B) copulatory phase; (C) terminal phase; and (D) post-copulatory phase.

An attempt to test the role of species specific patterns of peg setae, occurring on the genitalia of males, as a tactile signalling system was made by observation of inter-specific interactions between males and females of the two species. Under the trial conditions inter-specific intromission did not occur and behaviour was predominantly aggressive. Evidence suggests that signals during the early stages of an encounter between the sexes of different species are generally sufficient to deter further courtship. In two instances courtship reached a more advanced stage and here the patterns of peg setae on the male genitalia may have come into play, operating as a signalling device.     

LX.—Copepoda and Cladocera of the Cuillin Hills of the Isle of Skye

Summary

The life history of the African grasshopper Ornithacris turbida (Walker) was studied under controlled laboratory conditions. No phase variation was observed between isolated and crowded stock in respect of colour, morphometrics, weight of hatchlings or fledglings. All the females reared in isolation Had seven nymphal instars but in the case of the isolated males the majority had six but some had seven nymphal instars. This variation was also observed in the crowded stock for both males and females.

In isolation the mean nymphal life of 15 females was 78·7 ± 3·2 days, the mean for nine males having six instars was 59·9 ± 3·2 days and for five males having seven instars the mean nymphal life was 74·6 ± 3·8 days. Overall the nymphal life for the insects reared in crowds was slightly shorter, but no attempt was made to separate the insects having six or seven instars.

The stripes in the compound eye correlated with the number of nymphal instars. Colour changes in the compound eye coincided with overall body colour changes and maturation.

The mean maturation period of females reared in isolation was 101 days, varying from 72 to 158 days. The mean maturation period of the crowded females, estimated by the collection of the first egg-pod, was 73 days with a range of 62 to 84 days; when estimated by the collection of egg-pods averaging one per female it varied with the cage from 91 to 114 days. This suggests that maturation in the crowded females was quicker.

The isolated females lived longer than ones reared in crowded conditions, and laid more egg-pods. There was, however, no difference in the number of eggs per pod or their hatchability between crowded and isolated stock. In both cases 76% of the total number of eggs hatched. Hence overall the isolated females had a greater fecundity than those reared in crowds.

The average weight of a single hopper from isolated parents was 15·5 mg and that from crowded parents was 14·0 mg.     

XXXIII.—Description de quelques espèces nouvelles de Coccinellides

Summary

Mussels up to 20·0 mm in length were examined for parasitism by Mytilicola intestinalis, and it was found that infection seldom occurs in mussels smaller than 10·0 mm.

Reasons for the low infection rate in young mussels have been discussed.

Female parasites in young mussels were significantly smaller than those living in adult mussels.     

Schistosoma curassoni Brumpt, 1931 in sheep and goats in Senegal

A survey of 5722 sheep and 1752 goats at the abatoir in Dakar, Senegal showed that the overall prevalence of schistosomiasis was 2·1%. Of the 112 animals where identification of the schistosome species was possible, all were infected with Schistosoma curassoni, and 2·7% had mixed infections with S. bovis. The adult worms of S. curassoni are described, and on the basis of egg morphology this species is shown to be distinct from S. bovis and S. mattheei. Eggs of S. curassoni measured 146 μm ± 16·8 × 63·3 μm ± 4·5 from sheep and 149·4 μm ± 13·2 × 62·8 μm ± 4·9 from mouse liver, and appear to be indistinguishable from the eggs of S. haematobium Guede Chantier, Senegal which measure 153·1 μm ± 11·1 × 62·4 μm ± 12·1 from mouse liver. However, S. curassoni differs from S. haematobium in that it develops more quickly than S. haematobium in hamsters, uterine eggs becoming visible at least 20 days earlier; the adult worms of S. curassoni are nearly double the size of S. haematobium in hamsters at 70 days post infection.

Also, S. curassoni develops well in sheep and cattle unlike S. haematobium, but will not develop to maturity in baboons like S. haematobium.     

The larval development of Argulus coregoni Thorell (Crustacea: Branchiura)

Summary

The larval development of Argulus coregoni from the first to the ninth stage was studied, with special reference to the morphological changes of the appendages and some other parts of the body.

A newly hatched larva is a copepodid-form measuring 0·6–0·7 mm long and approaches the shape of the adult after moulting into the second stage (0·7–0·9 mm). Throughout the larval stages, the first maxilla shows the most remarkable modification. The larvae of the first to the fifth stage are equipped with two strong, curved claws, which act as a clasping organ, at the terminal segment of the first maxilla. The basal segment expands considerably at the third stage (0·9–1·1 mm) prior to forming a sucker at the sixth stage (1·7–2·2 mm). The claws start to degenerate at the fifth stage (1·4–1·8 mm), but are still recognizable as a rudiment after the seventh stage (2·2–2·6 mm). The other distinct morphological changes that occurred are: (1) bifurcation of the anterior part of the dorsal ridges on the carapace, (2) development of the male accessory copulatory organ at the basal segments of the second to the fourth legs, (3) number of posteriorly directed minute spines on the ventral surface of the carapace, (4) number of elements in the supporting ribs of the suckers, (5) number of spines found at the first segment of the second maxilla, and (6) number of setae on the four pairs of thoracic legs.

The larval forms of A. coregoni younger than the fourth stage (1·1–1·4 mm) are indistinguishable from those of A. japonicus and A. foliaceus.     

Integrative taxonomy of Thalerosphyrus Eaton, 1881 (Ephemeroptera,Heptageniidae) in Thailand

ABSTRACT

A comprehensive revision of the genus Thalerosphyrus in Thailand is assessed. Four species are recognised: T. flowersi, T. sinuosus, T. vietnamensis and one new species, Thalerosphyrus thailandensis sp. nov., which is described here. A morphological comparison of the described species is provided. A Maximum Likelihood (ML) consensus tree based on 658 bp of the mitochondrial cytochrome oxidase I (COI) gene of five species was performed. Uncorrected p-distances strongly support the identity of these species, originally based on morphology, and show differences of 8.4–29.8% between species and 1.4–6.3% within species.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:850FB31C-2B6A-4AB2-92D5-3413B193F196     

Studies on Alenophalera bronneomixia (Lepidoptera: Notodontidae)—a pest of the West African indigo plant,Lonchocarpus cyanescens (Papilionaceae)

Summary

This paper is concerned with the general biology of the notodontid moth, A. bronneomixia whose larvae are found to be serious defoliators of the West African indigo plant, Lonchocarpus cyanescens.

At temperatures fluctuating between 21°C and 29°C (mean 22·5°C) and humidities between 70 to 95 per cent eggs developed and hatched in a mean of 11·1 days from deposition, mean hatch being 93 per cent.

Under the said environmental conditions, the life cycle from egg to adult entailed six larval instars and a prepupal stage before the real pupa, all lasting 60 to 80 days. Larvae were strongly monophagous, fed communally and in nature pupated in soil/litter very close to the foot of their invaded food plant.

Adults were retiring and in the field deposited clusters of numerous eggs preferably on the abaxial surfaces of their food plants. In nature, this moth's population seemed strongly regulated by high egg and larval parasitization, larval predation and fungal attacks at the pupal stage.