Follicovitellosum indicum,a new trematode,found in the fish Belone belone

A new trematode, collected in 1971 from Ratnagiri, India, is described as Follicovitellosum indicum sp. nov. A new subfamily, Follicovitellotrematinae is created within the family Zoogonidae Odhner, 1911, to receive the new genus Follicovitellosum, with its genotype F. indicum. The new species is characterized by the follicularized nature of its ovary; the ovarian follicles are posttesticular. The vitellarium is further divided into several follicles which are largely in the pre-ovarian zone, but post-acetabular and posttesticular in location.     

Magellanic Bryozoa: Some ecological and zoogeographical aspects

This study summarizes observations made on more than 140 species obtained in Southern Chile and on many others collected from the Juan Fernández Islands to the Antarctic Peninsula from 1962 to 1980. The total number of the Magellanic Bryozoa including the author's records and those of the literature reaches 195. These species are: 15 Ctenostomata (7.69%), 46 Cyclostomata (23.59%) and 134 Cheilostomata (68.72%). Seven species are described as new: Arachnopusia admiranda sp. nov., Celleporella chiloensis sp. nov., Electra pilosissima sp. nov., Hippoporina chilota sp. nov., Parasmittina pluriavicularis sp. nov., Smittina ectoproctolitica sp. nov. and Smittina molarifera sp. nov. Typical characteristics of the Magellanic bryozoan fauna are: the Cyclostomata amount to 50% of all the subantarctic and antarctic species, with two endemic families Calvetiidae and Pseudidmoneidae; the Cheilostomata show a low endemism at the generic level compared to the antarctic group; the hippothoan fauna is very diversified with four species having tatiform ancestrulae. The zoarial diversity and the polymorphism of the Magellanic Bryozoa are qualitatively and quantitatively different from that of the Antarctic. Thus the encrusting species make up the main bulk of this bryozoan fauna with at least 110 spp. From a bryozoogeographical point of view the Magellanic Region comprises the following parts that could be considered as provinces: (a) Magellanic: including the southern tip of South America south to Lat. 40°S, plus the Patagonian Shelf and the Falkland Islands. (b) Tristan da Cunha and Gough Island. (c) Kerguelen and the nearby archipelagos in the Indian Sector of the Austral Ocean.     

Correlation between photosensitivity and downwelling irradiance in mesopelagic crustaceans

The current study determined behavioral and electrophysiological photosensitivities for three species of mesopelagic crustaceans: Pasiphaea multidentata Esmark, 1866 (Decapoda: Pasiphaeidae), Sergestes arcticus Kröyer, 1855 (Decapoda: Sergestidae), and Meganyctiphanes norvegica M. Sars, 1857 (Euphausiacea: Euphausiidae). In addition, in situ quantifications of the species vertical distributions in relation to downwelling irradiances were also determined in two locations in the northwest Atlantic Ocean, Wilkinson Basin (WB) and Oceanographer Canyon (OC). Data are from six 2-week cruises between June and September from 1995 to 2001. P. multidentata and M. norvegica were the most abundant large crustaceans in WB, and S. arcticus and M. norvegica were the most abundant large crustaceans in OC. The behavioral light sensitivity thresholds of P. multidentata and M. norvegica from WB were both 10⁷ photons cm^–2 s^–1 and those of S. arcticus and M. norvegica from OC were both 10⁸ photons cm^–2 s^–1. Electrophysiologically, P. multidentata was significantly more sensitive than M. norvegica from either location, S. arcticus was significantly more sensitive than M. norvegica from OC, and M. norvegica from WB was significantly more sensitive than M. norvegica from OC. A correlation was found between electrophysiologically measured photosensitivity and downwelling irradiance, with the most sensitive species, P. multidentata and S. arcticus, associated with the lowest irradiance at daytime depths. The photosensitivities of M. norvegica collected from the clearer waters of OC were significantly lower than those of individuals collected from the more turbid WB waters. These results indicate that downwelling irradiance has a significant impact on interspecies and intraspecies vertical distribution patterns in the mesopelagic realm.Communicated by J.P. Grassle, New Brunswick     

Fungi from the Sargasso Sea

Fungi inhabiting Sargassum spp. from the Sargasso Sea were examined. Three ascomycetes were found, two of which are new records for this environment. Haloguignardia oceanica (Ferdinandsen et Winge) Kohlm. comb. nov. was collected only once before, over 50 years ago. Haloguignardia tumefaciens (Cribb et Herbert) Cribb et Cribb was known only from Australia and New Zealand. Imperfect states of these ascomycetes and fruiting bodies (acervuli) of a hyperparasitic deuteromycete (cf. Sphaceloma sp.) were found for the first time in the galls of the two species. Lindra thalassiae Orpurt et al., previously known only from the sea grass Thalassia testudinum Köngig, develops in air bladders of Sargassum sp., causing a shedding of infested vesicles. Possible reasons for the rarity of fungal species and diseased plants in the Sargasso Sea are diseussed.Dedicated respectfully to my teacher, Professor Dr. H Drawert (Universität Famburg), on the occasion of his 60th birthday.     

Respiration and nitrogen excretion of zooplankton. II. Studies of the metabolic characteristics of starved animals

Respiration and nitrogen-excretion studies were carried out on several species of zooplankton (Meganyctiphanes norvegica, Phronima sedentaria, Acartia clausi and Sagitta setosa) under starvation. Although all the species were mainly ammonotelic, apparently a significant amount of organic nitrogen was excreted; the validity of the measurements and their significance are discussed. The effect of duration of starvation showed for M. norvegica and A. clausi two different patterns of behaviour, which were chiefly a function of the rate of biomass turnover of the species studied. The rates of metabolism, chemical composition, and reaction to starvation varied with season in M. norvegica. The physiological balance of the experimental animals was examined by calculating the protein carbon equivalent to respiratory and excretory catabolism, and by use of atomic O:N ratios. Starved individuals catabolized more protein carbon than can be accounted for by the amount of respiratory oxygen utilized. A hypothesis, which suggests that there are three levels of resistance to starvation, is proposed to explain this paradox, and its metabolic basis is discussed.     

Range extensions of teredinids (shipworms) and polychaetes in the vicinity of a temperate-zone nuclear generating station

A study of marine boring and fouling organisms in the vicinity of the thermal effluent from the Oyster Creek Nuclear Generating Station, Barnegat Bay, New Jersey, USA has been conducted since 1971. Two subtropical species of shipworms have been found in significant numbers in the effluent. These are Teredo bartschi Clapp and Teredo furcifera von Martens. The shipworm Lyrodus sp. and the flatworm Taenioplana teredini Hyman, which is predatory on teredinids, were also found, but on only one occasion. The polychaete Ficopomatus enigmaticus (Fauvel) has been found for the first time on the Atlantic Coast of North America. Three other polychaetes, Potamilla (Potamethus) spathiferus (Ehlers), Loimia medusa (Savigny), and Sphaerosyllis sp., have been newly identified from Barnegat Bay, but probably are not recent range extensions. Only T. bartschi, T. furcifera, and F. enigmaticus have established breeding populations. Their distributions and abundances are probably related to the thermal effluent; this is most clear in the case of T. bartschi and least clear in the case of F. enigmaticus. T. bartschi was confined at first to the heated effluent in Oyster Creek, but has spread to Forked River. It has become a major faunal element in Oyster Creek. The impact of the other exotic species has been negligible. The primary mechanism of the range extensions is by boat transport.     

Genetic evidence for cryptic speciation in allopatric populations of two cosmopolitan species of the calcareous sponge genusClathrina

Many sponge species are considered to be cosmopolitan. However, the systematics of marine sponges are very difficult because of the paucity of taxonomically useful characters, and hence the apparently cosmopolitan nature of many species may be simply a consequence of this. In this paper, geographically distant populations of two pairs of cosmopolitan calcareous sponges of the genusClathrina were compared genetically.C. clathrus andC. cerebrum were collected by SCUBA diving between January and March 1989 from two localities: the Mediterranean Sea at La Vesse, near Marseille, Frances, at 9 to 12 m depth, and from the South West Atlantic at Arraial do Cabo, about 200 km east of Rio de Janeiro, at 2 to 10 m depth. Very high levels of gene divergence were found between the allegedly conspecific populations. The levels of genetic identity,I, observed are so low (I=0.128 and 0.287) that the populations clearly cannot be considered conspecific. New species names ofC. aurea sp. nov. andC. brasiliensis sp. nov. are therefore assigned to the southwest Atlantic counterparts ofC. clathrus andC. cerebrum, respectively. It is concluded that, at least for the species studied, and probably for many other species in taxonomically difficult groups, the actual distributions of single species may be far more geographically restricted than is generally assumed.     

Functional divergence in heat shock response following rapid speciation of Fucus spp. in the Baltic Sea

In the Baltic Sea, the broadly distributed brown alga Fucus vesiculosus coexists in sympatry over part of its range (south west Gulf of Bothnia) with the Baltic endemic F. radicans sp. nov, while further north in colder and lower-salinity areas of the Baltic F. radicans occurs alone (north west Gulf of Bothnia). F. radicans appears to have arisen via rapid speciation from F. vesiculosus within the recent history of the Baltic (ca. 7500 BP). Possible functional divergence between the two species was investigated by comparing stress-responsive gene expression in a common-garden experiment. The experiment used two allopatric populations of Fucus vesiculosus from the Skagerrak (North Sea) and Central Baltic, as well as F. radicans from the same Central Baltic site. The two species in sympatry displayed divergent heat shock responses, while F. vesiculosus populations from allopatric sites did not. F. radicans was more sensitive to heat shock at 25°C, either alone or together with high irradiance and desiccation, than Baltic or Skagerrak F. vesiculosus. The results indicate that rapid functional divergence in the inducible heat shock response has occurred between sympatric species on a timescale of thousands of years.     

Comparison of laboratory rates of predation of five species of marine fish larvae by three planktonic invertebrates: effects of larval size on vulnerability

Rates of predation by the invertebrates Aurelia aurita, Thysanoessa raschi and Euchaeta norvegica on larval stages of cod (Gadus morhua L.), flunder (Platichthys flesus L.), plaice (Pleuronectes platessa L.), herring (Clupea harengus L.), and turbot (Scophthalmus maximus L.) were determined. Experiments were conducted in late winter and early spring 1982 with predators collected in Loch Etive, Scotland and prey obtained from several locations in Great Britain. Early stages of the smallest species, cod, flounder and turbot, tended to be most vulnerable to all three predators, while the early stages of the larger species, plaice and herring, and older stages of all species, were less vulnerable. For all stages and species of larvae, predation rates by the three predators were most closely related to larval length and escape swimming speed. Larval length itself was closely correlated to indices of larval escape ability. Low predation rates on large larvae by E. norvegica could be due to handling difficulties, whereas for A. aurita and T. raschi these low rates were due to escape abilities of the larger larvae. Prey movement is an important stimulus eliciting predation in E. norvegica but not in A. aurita or T. raschi.     

Structural investigations on the mucus from six species of coral

The chemical composition of the mucus from three hard corals (Acropora formosa, Pachyseris speciosa and Fungia fungites) and three soft corals (Sarcophyton sp., Lemnalia sp., and Cespitularia sp.) collected on the Great Barrier Reef (1982–1985) was determined. Significant variation exists in the composition and structure of the six mucus samples, indicating the absence of a common structure for coral mucus. In all cases protein and/or carbohydrate polymers are the major components of the mucus, and lipids are present only in small amounts. The glycose composition varied between species, with fucose (F. fungites and Lemnalia sp.), arabinose (A. formosa), galactose (P. speciosa) and N-acetyl glucosamine (Sarcophyton sp.) being present in high concentrations. With the exception of Sarcophyton sp. and Lemnalia sp., all mucus samples were acidic and contained significant sulphate but no uronic or sialic acids. The amino acid composition of the mucus samples was not unusual, apart from A. formosa, which contained a high percentage of serine and threonine, and F. fungites, which had high levels of glutamic acid present.     

A universal method for quantifying and comparing the residual variability of element concentrations in biological tissues using 25 elements in the mussel Mytilus edulis as a model

Heavy metal concentrations (especially Cu, Cd and Zn) have been measured in oceanic hyperiid amphipods (Themisto gaudichaudii and T. compressa) and euphausiids (Meganyctiphanes norvegica and Euphausia superba), collected in the Antarctic and Atlantic Oceans. In some cases, metal concentrations displayed size-dependencies which were allowed for in interspecific or intersite comparisons, which often showed intraspecific geographical differences not attributable to anthropogenic effects. Cadmium concentrations in Themisto species are high in comparison with those of other oceanic crustaceans and may represent significant sources of cadmium in the diets of particular seabrids.     

Seasonal variation in some population parameters of Euchaeta species (copepoda: Calanoida)

Studies of the biology of oceanic copepods are few relative to those of coastal species. Females of the genus Euchaeta have spermatophores attached to the genital somite by the male and carry their broods of eggs attached to this somite, so defining the breeding season. Populations of E. norvegica in the fjordic environment of Loch Etive (collected between 1971 and 1974 and from 1978 to 1979), Scotland and in the marginal oceanic region of the Rockall Trough, northeastern Atlantic Ocean (collected between 1973 and 1976) and of a further eight species of Euchaeta in the Trough are examined. Seasonal changes in the incidence of egg masses and spermatophores attached to the females, sex ratio and population numbers are determined. Sampling errors in the estimation of these parameters are larger in the oceanic Rockall Trough. The Loch Etive populations of E. norvegica produce two generations per year with a proportion, variable between years, of the population producing a third generation. This species produces a single annual generation in the Rockall Trough as do E. acuta and E. pseudotonsa. Two generations per year are probably passed through by E. gracilis in the Trough while the large bathypelagic E. sarsi may produce a single generation in the autumn of every second year. The other bathypelagic species, E. barbata, E. scotti, E. abbreviata and E. longissima, breed continuously throughout the year and no estimate of their generation times is possible. Consequently, this approach to population analysis is useful where breeding is seasonal, but resolving generation time in bathypelagic crustaceans remains a problem.     

The behavioural basis of a species replacement: differential aggresssion and predation between the introduced Gammarus pulex and the native G. duebeni celticus (Amphipoda)

Previous studies have shown that differential predation by males on moulted female congenerics may be largely responsible for the elimination and replacement of the native Irish freshwater amphipod Gammarus duebeni celticus by the introduced G. pulex. Predation of moulted females occurs both shortly after their release from precopulatory mate-guarding and whilst they are being guarded by their mates. In the present study, two hypotheses concerning the underlying cause(s) of the differential predation pattern are tested. Firstly, female G. d. celticus may be more vulnerable to predation than female G. pulex due to the former being released from precopula guarding with the new exoskeleton in a less hardened state. Secondly, G. pulex may be an inherently more aggressive species than G. d. celticus during predatory interactions over guarded females. The first experiment indicated that differential predation was not mediated by species differences in the state of the female exoskeleton at the time of release from precopula by guarding males. The second experiment, however, showed that male G. pulex were significantly more aggressive than male G. d. celticus in attacking both guarding male congenerics and guarded moulted female congenerics. In addition, in defence against predatory attacks, paired male and female G. pulex were significantly more aggressive than paired male and female G. d. celticus. These differences in aggressive behaviour led to a significantly higher frequency of predation on G. d. celticus females than on G. pulex females, and also explains this finding in previous studies. It is concluded that differential predation due to differences in aggressive behaviour may explain the pattern of replacement between these species.     

Ecological investigations on the zooplankton community in balsfjorden,northern Norway: Lipids and fatty acids in Meganyctiphanes norvegica,Thysanoessa raschi and T. inermis during mid-winter

Total lipid of Meganyctiphanes norvegica (M. Sars) contained 53% triacylglycerols and traces of wax esters, that of Thysanoessa raschi (M. Sars) contained 44% triacylglycerols and 10% wax esters and that of T. inermis (Krøyer) contained 28% triacylglycerols and 40% wax esters. The triacylglycerols of M. norvegica were relatively rich in 20:1 and 22:1 fatty acids and its traces of wax esters resembled those of calanoid copepods. The triacylglycerols of both Thysanoessa species were deficient in 20:1 and 22:1 fatty acids but were richer in 16:1(n-7) and 18:1 (n-7) acids than those of M. norvegica. The wax esters of T. raschi contained phytol as almost the only fatty alcohol and were rich in 16:0 and 18:1 (n-9) fatty acids. The wax esters of T. inermis contained mainly 16:0 and 14:0 fatty alcohols with lesser amounts of phytol and their dominant fatty acid was 18:1, especially the (n-9) isomer. The triacylglycerols of T. inermis had 18:4 (n-3) as the major polyunsaturated fatty acid. From these and other aspects of fatty acid and fatty alcohol analyses it is concluded that a major foodstuff of M. norvegica in Balsfjorden is wax ester-rich calanoid copepods. T. raschi and especially T. inermis are concluded to have much more preference for phytoplanktonic food. Results are discussed in terms of current knowledge of the lipid chemistry of krill in the northern and southern hemispheres.     

Microsetella norvegica: a rare report of a potentially abundant copepod on the Scotian Shelf

Fine mesh (0.080 mm) zooplankton samples were collected along an onshore-offshore transect during three cruises (February to May, 1983) off southwest Nova Scotia, Canada. The small harpacticoid copepod Microsetella norvegica was numerically the dominant copepod during the winter (February) cruise, where it composed up to 50% of the total zooplankton, and was consistently among the three most abundant copepods during the spring cruises. Due to its small size (<0.45 mm in length), M. norvegica has rarely been reported from plankton surveys of the northwest Atlantic. However, existing reports indicated it varies interannually from being a rare to an abundant member of the zooplankton community in the northwest Atlantic.     

Causative species of diarrhetic shellfish poisoning (DSP) in Norway

This study was performed at Vikane in the Sognefjord, Norway, from September 1987 to October 1988 on the blue musselMytilus edulis collected monthly at three different depths (3 to 6, 6 to 8 and 8 to 12 m). Cell numbers of three species ofDinophysis from mussel digestive glands and in seawater were counted for each specimen. Multivariable statistical methods were used to detect annual cycles of phytoplankton abundance in the fjord and to examine the contribution of each species to toxification of mussels. Cluster analysis and principal component analysis indicated the following results: (1) an annual cycle and an inter-specific association of threeDinophysis species populations were pointed out.D. acuta andD. norvegica were well associated over the entire period of this study, and exhibited an autumnal peak.D. acuminata was dissociated from these species and reached its maximum abundance between spring and early summer. (2) The threeDinophysis species induced toxicity in the blue mussels in different manners.D. acuta andD. norvegica were responsible for high autumnal toxicity, andD. acuminata for the spring peak. (3) A long persistence of diarrhetic shellfish poisoning (DSP) in blue mussels (from April to February), and a depth gradient of toxicity were observed — the toxicity value in the upper layer being double those of other depths.     

Halistaura bruuni sp. nov. (Leptomedusae,Mitrocomidae) with notes on its distribution and ecology

A new hydromedusa collected in 1963 in the Bay of Bengal during the International Indian Ocean Expedition by the RV Anton Bruun is here described as Halistaura bruuni sp. nov. Some environmental data are given. The new species is characterized by a number of open marginal vesicles approximately equal to that of the tentacles, oval gonads on the distal half of the radial canals, and by the presence of nematocyst depots in the tentacle bulbs.Publ. No. 273 of the Instituto Oceanográfico da U. S. P.     

Studies on the mechanism of biosynthesis of wax esters in Euchaeta norvegica

Preparations of Euchaeta norvegica catalyse the incorporation of (1-¹⁴C) hexadecanol, (9,10-³H₂) oleic acid, (U-¹⁴C) glucose, (U-¹⁴C) alanine and (U-¹⁴C) aspartic acid into wax esters. Both the fatty alcohol and fatty acid moieties of the wax esters are labelled, indicating de novo biosynthesis. A limited interconversion of fatty acid and fatty alcohol has been demonstrated. Incorporation of glucose into wax esters is diminished by prior starving of E. norvegica; it is also reduced in the presence of ecdysterone. Formation of wax esters from glucose is inhibited by increased oxygen tensions, rotenone and dinitrophenol, and is relatively insensitive to decreased oxygen tensions and cyanide. The data are discussed with particular reference to the reasons why wax esters are biosynthesised by calanoids.     

Observations sur le développement larvaire de Meganyctiphanes norvegica (Crustacea: Euphausiacea) au laboratoire

Larvae of Meganyctiphanes norvegica (M. Sars), caught with a plankton net, were reared in the laboratory from the calyptopis phase onwards, under different temperature and trophic conditions. Eyestalk ablation was performed on the first furciliae. Data are presented on growth, moulting rate and ontogenesis of the larvae as a function of the varying experimental conditions, and on larval morphology, pigmentation and diet. Recent modifications of larval nomenclature in euphausiids are discussed.

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Observations sur le développement larvaire de Meganyctiphanes norvegica (Crustacea: Euphausiacea) au laboratoire