Observations are described upon the innervation of striated muscles, the innervation of the slime glands, and the subcutaneous innervation in the hagfish, Myxine glutinosa L. It is shown that the two types of striated muscle fibre receive different types of motor innervation. Presumed sensory endings are described from above the striated muscle fibres of the ventral part of the body, and are similar to those endings near to the dorsal root ganglia whichcan be traced to their cells of origin within the ganglia. It is suggested that these endings are proprioceptive in function. Other endings within the outer edge of the myosepta are described, which may possibly also have a proprioceptive function. A rich plexus of neurons is described upon the capsule of the slime glands, and these neurons, like those of the subcutaneous plexus, receive pericellular terminations from the axons of central cells. It is suggested that they are motor to smooth muscle fibres, in the slime-gland plexus being related to the expulsion of slime (together with the action of striated muscle fibres), and in the subcutaneous plexus playing some role in the control of the venous blood in the subcutaneous sinuses.

Certain endomyarian sea anemones possess marginal spherules or acrorhagi (Stephenson, 1928) which are employed only in aggressive behaviour towards other Anthozoa. The acrorhagi can be dilated and movements of the oral disc and column bring them into contact with an adversary. Pieces of acrorhagial ectoderm adhere to the body of the adversary whilst discharging into it the large atrich nematocysts characteristic of acrorhagi. Such behaviour has been described in the European anemone Actinia equina (L.) and the Californian anemones Anthopleura elegantissima (Brandt) and Anthopleura artemisia (Dana) (Äbel, 1954; Bonnin, 1964; Francis, 1973). Aggression usually occurs only following repeated contact with a genotypically distinct anemone: mere proximity does not usually initiate any response (Francis, 1973).

I have recently seen similar behaviour, apparently not recorded before, in the European anemone Anthopleura ballii (Cocks) collected from Weymouth, England. Specimens were kept in an aerated aquarium with other anemones and fed irregularly: the behaviour observed occurred between 19.00 and 22.00 h G.M.T. during August and November 1977. Following contact between two specimens of different colour varieties and the subsequent use of acrorhagi by one of them, the light-coloured passive individual immediately moved away from the dark-coloured aggressor and remained partly contracted with a ‘withered’ appearance to the tentacles for 1 week, following which it recovered (August). The same aggressor later (November) attacked a Cereus pedunculatus (Pennant), causing it to detach immediately from the substrate and to become necrotic one day later. The Cereus remained detached with the tentacles retracted and the column swollen for 5 days before it recovered.

The spatial and temporal variations of planktonic cnidarians were studied across the inner continental shelf (≤40 m) off the State of Paraná in southern Brazil. Monthly zooplankton samples were taken between November 1997 and March 1999 at five stations. The holoplanktonic Liriope tetraphylla and Muggiaea kochi dominated during the entire period, comprising >80% of the specimens. The coast–ocean gradient became evident due to a near-coastal (≤20 m) assemblage formed by L. tetraphylla, Solmaris corona and meroplanktonic medusae, and a distinct outer (25–40 m) assemblage formed by the medusae Corymorpha gracilis and Aglaura hemistoma and siphonophores. The estuarine runoff during warm rainy periods lowered the salinity (~30) at the inner stations (1, 2 and 3), providing appropriate conditions for the estuarine/coastal species. Wind-driven onshore advection of outer-shelf species to the inner isobaths occurred from late autumn to winter, when the rainfall decreased and salinity increased (>35). Population peaks occurred in both summer and winter at the inner stations. For most species, the seasonal patterns were inconsistent with other studies conducted in the Southern Brazilian Bight, suggesting irregular and unpredictable seasonal distributions of abundance. Whereas in high-latitude ecosystems the dynamics of cnidarian populations follows the seasonal productivity cycle, here, complex hydrographic processes seem to be more important in determining the structure and seasonal dynamics of this community.

A number of workers have studied the uptake of zinc by algae, but the mechanisms of uptake are not fully understood. Broda, Desser & Findennegg (1964) concluded that 65Zn uptake by Chlorella was a passive process since it was affected neither by metabolic inhibitors nor by anaerobic conditions. In later papers, however, Broda and co-workers (Matzku & Broda, 1970; Findennegg, Paschinger & Broda, 1971) have concluded that 65Zn uptake occurs both by a rapid passive process of ion-exchange and also by a slower, metabolically dependent process. Bachmann & Odum (1960) showed that65Zn uptake by Chaetomorpha was stimulated by light and they concluded that uptake was a metabolically active process. Gutknecht (1961,1963) showed that uptake of65Zn by Viva and Porphyra was stimulated by illumination and by increase in temperature. He also showed that increase in pH of the surrounding medium increased65Zn uptake and thus concluded that65Zn uptake was a passive process which was affected indirectly by metabolism.

falkland islands' mullet (eleginops maclovinus) were aged successfully using whole sagittal otoliths from 1403 individuals. marginal increment analysis indicated that one opaque and one translucent zone were laid down annually. unvalidated daily ring counts confirmed what was thought to be the first translucent zone. the translucent zones were found to form earlier in juveniles than in adults. juveniles over winter in the creeks and inlets whereas adults are more common in deeper inshore waters where there is a one month lag in the minimum winter water-temperature. the maximum observed age was found to be 11 years. the calculated von bertalanffy growth model (lt=124.41(1−e−0.14/year(t-0.01years))) showed that e. maclovinus is a fast-growing fish, growing on average 10.2 cm/year for the first six years of its life.

Supralittoral splashpools representing 312,000 m2 of shoreline in Barkley Sound, British Columbia, were surveyed seasonally for tidal elevation, size, water properties, macroflora and faunal constituents coincident with colonization by Tigriopus californicus (Arthropoda: Copepoda). Overall, 90.1% of pools containing T. californicus were found between 3.0 and 5.0 m above lowest normal tide, with an average surface area-to-volume ratio of 7.06. Copepod populations were found at water temperatures of 6–33°C; salinity of <1–139 psu; pH of 6.1–9.5; and of 1.1–13.7 mg l−1 oxygen. Sediment and vegetation was sparse in T. californicus pools (mean cover 15.79±10.6% in 9.4±11.1% of pools, all species), and consisted most commonly of Enteromorpha compressa and Scytosiphon lomentaria and its Ralfsia-like alternate phase. Common fauna included mites, amphipods, littorines, and nematodes, with the highest diversity of co-inhabitants occurring in spring. Factors such as wind, wave action, and incidental fauna are discussed as potential agents of dispersal for splashpool copepods.

The dogwhelk Nucella lapillus experienced localized extinction in the 1980s and 1990s due to the use of tributyltin (TBT) antifoulants, causing imposex in females. The aim of this study was to establish the extent of the return of the species across the mainland coast of central southern England as TBT use has been progressively restricted, and to quantify the extent of imposex impact on the populations present. We surveyed from Poole to Selsey where isolated populations had become extinct, and the Isle of Wight where some populations had persisted. We found evidence that since TBT restrictions, recolonization and colonization by N. lapillus has been rapid. By 2007–2008, of the eleven surveyed mainland sites, seven were colonized, although indications of reduced imposex impacts were mixed. Distribution had also extended on the Isle of Wight and populations were larger with less imposex impact in sites with long term populations. The lack of continuous suitable habitat blocks and the hydrodynamic complexity of the region, leads us to hypothesize that recovery has been facilitated by man-made structures which may be acting as ‘stepping stones’. Populations that have become established on engineered structures such as sea walls, breakwaters and rock groynes demonstrate accelerated recovery in the region as TBT in the environment has generally declined. Sites with suitable substrates and food sources near to ports were either not recolonized or had small populations with imposex evident. For species with a short pelagic larval stage or with direct development, population connectivity between patches of harder substrata along hydrodynamically complex coastlines may be greater than previously thought.

The diet and the feeding habits of the common dolphinfish (Coryphaena hippurus) in the Pacific coast of Ecuador was assessed by examining 320 stomachs of individuals ranging from 51 to 149 cm in total length. Fish was the predominant prey group in the diet (Alimentary Index, %AI = 95.39) followed by cephalopods (%AI = 4.13) and crustaceans (%AI = 0.48). Among the 17 prey items that make up the dolphinfish diet, the Exocoetidae family was the most important prey (%AI = 57.13), Dosidicus gigas being the most abundant invertebrate species (%AI = 7.65). Feeding patterns were evaluated using the graphing method of Amundsen, which suggested that this species shows a varying degree of specialization on different prey taxa. Thus, while some species were unimportant and rare (Hippocampus hippocampus, Lagocephalus lagocephalus, Gobiidae and Argonauta sp.), several dolphinfishes showed a high degree of specialization on Scombridae, Pleuroncodes planipes, Portunus xantusii and Opisthonema libertate. Size-related and temporal shifts in dietary composition were investigated by PERMANOVA analysis, which showed wide variations among size classes and periods of capture. The results of this study indicate that the common dolphinfish is an opportunistic feeder, which is capable of consuming a wide variety of schooling epipelagic organisms.

Diel fluctuations in nearshore fish communities were studied at a sandy beach in south-eastern Brazil. A total of 192 samples were performed by beach seines, during 3-hour intervals throughout 48-hour periods, between spring 2005 and winter 2006. Mean biomass and number of species were significantly higher at night, while number of individuals did not differ between day and night. Major disruptions in the fish community occurred during the winter when the assemblages underwent restructuring. Harengula clupeola, Sardinella janeiro, Anchoa lyoleps and Umbrina coroides were the predominant species at night, while Atherinella brasiliensis, Pomatomus saltatrix and Trachinotus carolinus peaked during the day, although significant diel changes in community structure were recorded only in the summer. Biological interactions, behavioural variations and local constraints might explain diel differences in the fish distribution. This study confirms that changes in diel activity in juvenile fish species can differ in similar areas, even for a given species, and the causes of these changes needs to be investigated.

Marine species new to science continue to be discovered around Britain and Ireland. The number of marine species described each year was plotted against time for Pisces, Echinodermata, Anthozoa, Bivalvia, Decapoda, Gastropoda, Bryozoa, Tunicata, Medusozoa, Amphipoda, Porifera, Nudibranchia, Polychaeta, Copepoda, Oligochaeta, and Nematoda. Trends suggest that the latter four taxa in particular, in which individuals generally have a small body size, still have many species remaining to be described. More conspicuous taxa are better known, but new species continue to be described. Whilst the World Wars and advent of new scientific techniques do not appear to have had significant impacts on the general trends in discovery of new species, individual scientists have made major contributions.

Several Synalpheus species have been reported as hosts of bopyrid parasites; however, the impact of infestation on egg production is still unknown. Therefore, the present work studied reproductive aspects and the effect of parasitism on fecundity of the alpheid shrimp Synalpheus yano from Bocas del Toro, Caribbean coast of Panama. Un-infested females (N = 84) ranging from 3.7 to 9.6 mm carapace length, produced between 5 and 246 eggs (average: 98±64.6), and egg number increased significantly with female size. The eggs were relatively large (0.6–1.3 mm in diameter), but within the range of other Synalpheus species, and egg size did not differ significantly between un-infested and infested females. Despite these large eggs, the morphological characteristics of hatching larvae indicate a planktotrophic development. During the incubation period, the egg volume increased from 0.100 to 0.218 mm3, representing an overall increase of 118%. A total of 18 females (16% of all ovigerous individuals) were infested, and the occurrence of parasitic infestation was more pronounced in larger females. Infested females ranging from 4.6 to 9.4 mm carapace length, produced between 22 and 166 eggs (average: 81±44.4). Egg-bearing females infested by parasitic bopyrids carried on average 41% fewer eggs than similar-sized females without parasites. The co-occurrence of parasites and developing eggs, however, indicates that the bopyrid parasite does not necessarily castrate its host. Therefore, we encourage more comparative intraspecific studies on egg production in infested and un-infested females to assess the impact of infestation on fecundity in caridean shrimp.

The eggs of the polyopisthocotylean monogenean Plectanocotyle gurnardi (van Beneden & Hesse, 1863) Llewellyn, 1941, from the gills of gurnards (Triglidae) develop and hatch readily when maintained in the laboratory. However, the impression was gained that some or all of this hatching might be the consequence of inadvertent shadowing or accidental mechanical disturbance of the eggs by the investigators. Since similar stimuli are known to induce hatching in some other monogeneans (see Kearn, 1982; Whittington & Kearn, 1988) and since such stimuli are likely to be generated by the activities of potential hosts, it was decided to embark on a more detailed investigation of hatching in P. gurnardi and to attempt to learn more about the behaviour of gurnards. During these investigations, the availability of freshly hatched larvae of P. gurnardi presented an opportunity to study their behaviour and to expand our knowledge of their anatomy.

The population dynamics in the coastal bacterioplankton community off Plymouth (UK) was studied in samples proportionally diluted (99%, 90%, 66% and 0%) with sterile seawater, incubated in the dark for 2–4 days and monitored by flow cytometry. Nucleic acid content of cells, stained with SYBR Green I DNA specific dye, was used as an index of a genome size. Using flow sorting and fluorescence in situ hybridization (FISH) with a set of ribosomal RNA targeted oligonucleotide probes, the phylogenetic composition of dominant cytometric groups of bacterioplankton was determined to be similar during growth in the dilution series. The proportion of the low nucleic acid (LNA) group decreased and correspondingly the high nucleic acid (HNA) groups increased with dilution. The assimilation rates of free amino acids, a highly labile nutrient pool, were determined by flow sorting the dominant groups after short incubations with 35S-methionine tracer. The relative cellular amino acid assimilation by the LNA cells increased with dilution, while the activity of the HNA cells either decreased or remained unchanged. However, highly metabolically active LNA bacteria were overgrown by the HNA bacteria, presumably because the small genome size—an adaptation to living in an oligotrophic environment—did not allow the LNA group to grow sufficiently fast to compete with the HNA group under experimentally reduced grazing pressure. To examine the experimental results a numerical model of bacterioplankton population dynamics was formulated based on the hypothesis that the LNA cells consume only a labile fraction of organic nutrients (amino acids etc.), while the HNA cells feed on both the labile and more refractory sources of nutrients, and that in the absence of phytoplankton the labile source of nutrients is produced entirely by the bacterivorous flagellates. The model simulations gave credence to the hypothesized primary dependence of the LNA group on labile organic nutrients recycled within the microbial loop.

Low concentrations of various carcinogenic polycyclic aromatic hydrocarbons cause a considerable increase in cell production when applied to sporelings of certain marine red algae.

Whereas low concentrations of carcinogenic derivatives of benzanthracene stimulate cell production, similar concentrations of structurally related non-carcinogens inhibit it.

The applicability of the method as a rapid screening test for carcinogens is discussed.

INTRODUCTION

Initially the haptonema was recorded as a ‘little additional flagellum’ by Scherffel (1899) when he described Phaeocystis globosa. Similarly, the haptonema was referred to as the ‘third flagellum’ on the apparently tri-flagellate, brackish-water Prymnesium saltans Massart (Massart, 1920). Two further brackish water species of Prymnesium were described by Carter (1937) and all were characterized by a very short immobile ‘third appendage’. Lackey (1939) found a freshwater organism similar to Prymnesium but it possessed a ‘third flagellum’ several times the length of the true flagella. He re-corded that the third appendage was held out rigidly when the cell was at rest but during rapid swimming he was unable to see it and thought that this was due to an extremely rapid beat. He named his new organism Chrysochromulina parva and C. parva Lackey is now the type species of a considerable genus.

Parke, Manton & Clarke (1955,1956,1958,1959) made a study of the light microscopy and fine structure of numerous marine species of Chrysochromulina. Their results showed that the ‘third flagellum’ differed in appearance and structure from that of a true flagellum and hence they decided to call this organelle a haptonema owing to its thread-like form and its ability to adhere to a smooth surface (Parke, Manton & Clarke, 1955). Their observations revealed that the haptonema could attach to a surface by an ‘adhesive tip’ and that the majority of species could coil their haptonemata into a helix and extend it again. In some species, e.g. C. strobilus (Parke, Manton & Clarke, 1959), the haptonema was usually tightly coiled whilst the cell was swimming.

The effect of copper upon carbon fixation in coastal phytoplankton assemblages has been studied in relation to both the metal concentration in the water and the levels taken up by the plant cells. The phytoplankton populations were those present in water samples collected from Station L4 in the English Channel in the late autumn of 1979. The lowest copper concentrations causing detectable inhibition of photosynthesis lay in the range 1–25 μg/1, well below the levels which have been reported to be present in some sea areas around the British Isles; metal pollution may thus be influencing primary production in these contaminated regions.

The exceptionally heavy settlement of larvae in the autumn of 1970 made it imperative to continue the observations of the previous ten years. This two-year extension has yielded much new knowledge about the growth of Sabellaria colonies at Duckpool, and about other aspects of their life. It revealed that the more densely packed the young were the faster their colony grew, provided conditions were favourable. In unfavourable circumstances close packing of young delayed growth. The rapid elongation of young tubes surrounding older tubes sometimes resulted in holes and fissures forming when the older worms failed to maintain all-round contact with surrounding young as the surface area of a colony increased. Such holes and fissures gave a false appearance of physical damage, and in colonies where they formed weakened the whole structure, becoming a factor in its ultimate destruction by wave action. Such fast-growing colonies have shorter lives than others growing more slowly and remaining more compact.

The composition of subtidal meiobenthic associations off the Isle of Man is analysed, with particular reference to the harpacticoid copepods. By comparisons with surveys in other seas it is suggested that coherent associations of benthic copepods can be recognized in the sublittoral fringe area of tidal fine sand beaches and in offshore fine sand in Europe. The heterogeneity of offshore coarse deposits and muddy sands results in the inability to distinguish communities or isocommunities in these deposits. As muddy sand grades into mud some evidence is presented to suggest that, given similar temperature and salinity regimes, a consistent association of copepods may develop.

Ontogenetic changes in the body morphology, morphometrics, age, growth, maturation, fecundity, feeding spectrum and parasites were studied in 218 specimens of the oceanic nektonic squid Onychoteuthis banksi and in two specimens of the rare planktonic squid Chaunoteuthis mollis (Onychoteuthidae) caught in the tropical waters between 1977 and 1990. Similarities between the two species in major taxonomic features and in several morphometrical indices suggest that C. mollis is in fact a mature female of O. banksi with degenerated mantle and fin muscles and lost tentacles. Thus, C. mollis will be considered as a lesser synonym of O. banksi. Statolith microstructure analysis reveals that O. banksi is a slow-growing squid with low maturation rates, spending the first 240–260 d of life in the epipelagic zone. The main features of the reproductive strategy include earlier maturation of the males, small eggs (0.2–0.5 mm in diameter by the end of protoplasmic growth), synchronous development of oocytes and high potential fecundity (51,000–205,000 eggs). Onychoteuthis banksi is an opportunistic predator, shifting to a fish and squid diet much earlier and at smaller sizes (20–40 mm ML) than ommastrephid squid. The feeding activity of small and medium O. banksi (20–80 mm ML) is a little higher and that of large O. banksi (80–148 mm ML) is lower than in ommastrephids of the same size. The helminth fauna of O. banksi is impoverished and consists of ‘food parasites’: larval Didymozoidea and Scolex spp. The level of infection is low, only reaching -52 specimens per host in large squid. The nature of the life cycle of O. banksi and possible evolutionary trends in the development of the ‘Chaunoteuthis’ stage for maturation and spawning of females in the deep water are discussed.

The population structure of Mithraculus forceps sampled monthly on Anchieta Island from January 1999 to December 2000 was studied. A total of 68 individuals were collected by SCUBA diving. The population presented normal and unimodal distribution, and the total sex ratio was 1·4:1·0 in favour of males. Ovigerous females were captured during all seasons. The pattern observed for the M. forceps population in Anchieta Island indicated the strategy favoured by environmental characteristics of the island and by coexistence with other decapod crustaceans in the studied area.