Sampling cruises were carried out on three coastal stations of the northern Ionian Sea over one year to investigate the effects of environmental factors on phytoplankton and picophytoplankton composition and succession. Larger phytoplankton (micro and nano fractions) was determined by using the Utermöhl settling technique, while picophytoplankton fraction was determined by epifluorescence microscopy. Furthermore, microbiological procedures were applied to investigate cyanobacterial diversity in the studied area. Results suggested that the most striking feature of phytoplankton communities was the high spatial variability in terms of abundance and biomass, which showed specific coastal Mediterranean values. Undetermined phytoflagellates and diatoms were the dominant groups of the Utermöhl fraction of phytoplankton, while round to rod-shaped small sized cyanobacteria represented the picophytoplankton fraction. Our data suggested that in the northern Ionian Sea the phytoplankton development was related to phosphorus availability and to ‘nitrogen-rich’ waters. Also the picophytoplankton seasonal trend was significantly correlated to N-compounds as well as to water temperature.

In addition to the typical picoplanktonic Synechococcus, the culture techniques allowed us to isolate and identify cyanobacteria belonging to the pleurocapsalean genus Stanieria and the oscillatoriacean genera Geitlerinema, Leiblenia, Leptolyngbya, Oscillatoria, Pseudanabaena and Spirulina. These species represent a minor fraction of the total cyanobacterial community in terms of biomass, but their importance is related to their contribution to the phytoplankton diversity.

Video transects of epibenthic communities provide a valuable and non-destructive surveying methodology. The use of unstable platforms for video collection, such as divers and remotely operated vehicles, can lead to variation in the field of view, and consequently the dimensions of the surveyed area. Unless this can be accounted for, quantifying the species present can be time consuming or unworkable. Use of time-based, rather than areas-based, enumeration techniques, such as the visual fast count (VFC), can overcome this variation. Using seabed video footage from Strangford Lough, the reliability of the VFC was assessed through comparison with direct counts. Multivariate analysis of variance indicates that data derived from the VFC did not differ from that obtained from direct counts. Pairwise comparisons between locations in Strangford Lough using analysis of similarities (PRIMER) also indicated good agreement between the two methods. Use of the VFC method therefore provides: (1) a reliable alternative to direct counts for epibenthic enumeration; (2) a substantial reduction in post-survey processing time and; (3) a method capable of allowing variation in the visual field/sampled area.

Lough Hyne time series records showed a clear increase in vertical mixing associated with spring tides. Temperature records from the thermocline region were the most variable of the depths studied with differences of up to 0.7°C between readings taken 3 min apart.

A new species of Biemna, Biemnastrongylota sp. nov. is described from Antarctica. The new species is compared to other Antarctic species of Biemna, B. chilensis and B. macrorhaphis from which it differs in that it possesses strongyle megascleres, instead of styles, and of the microsclere complement which includes microxeas, raphides and two categories of sigmata.

This article reports on a new species originating from the northern Chilean fjord region, which argued for the resurrection of Cornulotrocha, here classified as a new subgenus of Clathria, for sponges with choanosomal acanthostyles, ectosomal quasidiactinal monactines and rosettes of palmate (an)isochelae. Clathria (Cornulotrocha) rosetafiordica sp. nov. was collected at 23 m depth at Quintupeu fjord (∼42°S), and is unique within this very large genus, in possessing rosettes of palmate anisochelae. The new species is compared to the only other known Clathria (Cornulotrocha), viz. C. (Cornulotrocha) cheliradians n. comb.; to the single other Clathria known with anisochelae, viz C. (Thalysias) dubia; to other crustose Clathria from southern South America, the subantarctic and Antarctic areas; and also to other sponges bearing rosettes; and is considered clearly distinct from all. The phylogenetic significance of rosettes is discussed, a likely adaptive value being discarded in view of the variable location of such structures in the distinct poecilosclerid taxa in which they occur.

Two alpha growth form species of boring sponges, Clionapocillopora sp. nov. and Cliona mucronata are described from coral reefs in the Mexican Pacific Ocean. Clionapocillopora sp. nov. is a light brown sponge containing tylostyles that measure 146×5 μm. Tylostyles are generally curved and have a globular or mucronated head, sometimes placed at some distance from the proximal end. In addition, straight, short and thick tylostrongyles and centrotylote oxea occasionally appear. Cliona mucronata is reported for the first time in the eastern Pacific Ocean. It is a red to red-orange sponge with two types of tylostyles, long and slender tylostyles, and short ensiform tylostyles. Both species have been found exclusively excavating corals of the genus Pocillopora. The boring activity of Clionapocillopora sp. nov. produces a network of galleries with mainly rectangular or polygonal chambers measuring from 0.7 to 2.4 mm in diameter, and C. mucronata produces a network of reticulate galleries with irregularly spherical or ovoid chambers 1.14×0.67 mm in diameter.

A new species of Erylus from the Aleutian Islands is described. This is the first record of the genus from the Aleutian Islands. The new species differs from all other known species of Erylus in the presence of different types of monaxonic megascleres, ranging from oxeas, strongyles, styles, tylostyles to tylotes, often with unequal ends and irregular modifications of these types. The lack of a secondary category of asters is also unusual for the genus.

Although the factors influencing patterns of expansion and contraction of polyps and tentacles for tropical anthozoans has been well described there is still little information for temperate species. This study investigated the patterns of tentacle and polyp expansion behaviour of nine species of temperate Anthozoa in response to current flow, turbulence, food availability and time of day (light) at Lough Hyne Marine Nature Reserve (Ireland). In the absence of current flow, Metridium senile, Caryophyllia smithii, Alcyonium hibernicum and Corynactis viridis exhibited nocturnal expansion of polyps or tentacles with contraction occurring in the daytime, while Alcyonium digitatum, Actinia equina and Cerianthus lloydii showed no differences between light and dark periods. The symbiont containing species Anthopleura ballii and Anemonia viridis expanded or raised their tentacles during daylight hours (tentacle contraction is not possible for A. viridis), although in shallow waters (3 m) Anthopleura ballii tentacles were contracted at midday (highest light levels) presumably to prevent damage from ultraviolet radiation. The contraction of tentacles during light periods was considered a predator avoidance response since zooplankton availability did not vary between light and dark periods, while predator abundance (particularly fish) is greater during daylight. Even though M. senile, Alcyonium hibernicum and Corynactis viridis showed little expansion during daylight periods in the absence of current flow, tentacles and polyps were expanded at midday during periods of high current flow. A greater number of expanded polyps and tentacles were also recorded for A. digitatum, Anemonia viridis and Cerianthus lloydii during high flow conditions compared with periods of low/no flow (Caryophyllia smithii not examined). Actinia equina only exhibited tentacle expansion in response to the creation of a turbulent flow regime, which was determined from laboratory observations. Since species demonstrating contraction during daylight in the absence of current flow expanded their tentacles and polyps when subjected to high current flow, the need for feeding appears to be more important than predator avoidance in controlling expansion behaviour.

A new partially calcified hydroid species of the family Hydractiniidae, was found in offshore waters of the Aleutian Islands (Alaska), dredged from the bottom at 139–145 m depth. This is the third known species of extant calcified Hydractiniidae, and it shows a unique colony structure. The base is heavily calcified and the distal parts are ramified and have a solid chitinous structure. Branches are all in one plane and the colony reaches up to 18 cm in height.

Comparisons are made between the species currently called Clausophyes ovata and other Clausophyes species. It is concluded that Cl. ovata should be removed to another genus and, consequently, the genus Kephyes gen. nov. is established for it. The relationships of all clausophyid genera are briefly discussed.

During a survey of the Italian marine meiofauna, several specimens of the rare gastrotrich genus Xenodasys were found in a submarine cave along the Ionian coast of Apulia. The finding represents the first record of the genus for the Mediterranean Sea and reinforces the consideration of marine caves as habitats of high naturalistic value. The specimens, analysed using different microscopy techniques, showed a new species, named Xenodasys eknomios. Scanning electron microscopy, unveiling the astonishing morphology of this unusual gastrotrich, indicates that, due to technical artefacts, light microscopy may generate unreal features, which in the past may have led to the misinterpretation of the anatomical traits of these creatures. Transmission electron microscopy indicated that the ‘Seitenfüsschen’, are genuine elements of the adhesive apparatus, in contrast with previous investigation, which attributed an exclusive sensorial function to these organs. Confocal laser scanning microscopy, combined with actin-binding fluorochromes, revealed muscular elements in a region where originally the muscular chordoid organ was reported for gastrotrich species belonging to the genus Chordodasys. A taxonomic revision of the species currently allocated to the genus Xenodasys led to the establishment of Chordodasiopsis gen. nov. to integrate the former Xenodasys (=Chordodasys) antennatus and to the drafting of emended diagnosis of the genus Xenodasys. An overview of the high-rank systematization of these genera is also provided, with the establishment of Xenodasyidae fam. nov. to allocate both Xenodasys and Chordodasiopsis.

The long discussion on the identity of the large Eunice species from the Adriatic and Mediterranean Seas is a result of the broader discussion on the identity and synonymy of Eunice roussaei and Eunice aphroditois. Here we show that the species occurring in the Adriatic Sea is Eunice roussaei and how this species can be differentiated from Eunice aphroditois; we also characterize the Mediterranean Eunice roussaei.

A new species of Polygordiidae, Polygordius jouinae sp. nov., along with its distribution, habitat, and reproduction is described. Polygordius jouinae sp. nov., the first North American Polygordius, is a dominant member of macrofaunal communities on the inner continental shelf, and in bays and harbours from Massachusetts to southern New Jersey. It is distinguished from most other Polygordius species by its non-inflated, heavily ciliated pygidium, absence of pygidial glands, and a conical (rather than rounded) prostomium. The 18S SSU rDNA from P. jouinae sp. nov. was sequenced and represents the first named Polygordius species with a DNA reference in GenBank. Spearman rank correlation of sediment grain size with density of P. jouinae sp. nov. at a New Jersey site showed that density was significantly (P<0.05; N=92) positively correlated with the proportion of medium to very coarse sand and negatively correlated with the fine sand fractions. Ecologically, P. jouinae sp. nov. is an important macrofaunal species given its widespread distribution and its fidelity for coarse sand habitats. Thus, its relative abundance may be useful as an indicator of changing sedimentary conditions.

Study of type and other material using scanning electron microscopy has permitted the recognition of three new species and one new genus of Arctic and boreal calloporid anascans. Originally described from the Gulf of St Lawrence, Callopora whiteavesi is reassigned to Flustrellaria, a calloporid genus not previously reported extant. Material from north-east Greenland misidentified as C. whiteavesi is described as C. weslawski sp. nov. The new genus Septentriopora is introduced for calloporids lacking pore chambers, with a distolateral pair of small interzooidal avicularia that face proximally or proximolaterally, and a reduced ovicell. The type species of Septentriopora, Tegella nigrans, has frequently been misidentified. Many of the supposed records of this species belong to two other species, described here as Septentriopora karasi sp. nov. and S. denisenkoae sp. nov. The apparent ovicell in S. karasi is particularly unusual, being vestigial and kenozooid-like in morphology.

Two new species of free-living marine nematodes of the genus Elzalia, Elzalia gerlachi sp. nov. and Elzalia striatitenuis sp. nov. from the Yellow Sea, China, are described and illustrated. Elzalia gerlachi sp. nov. is characterized by relatively large body length (1540–1740 μm in males; 1510–1780 μm in females), spicules 135–160 μm (3.33–3.90 anal body diameter) and complex gubernaculum. Elzalia striatitenuis sp. nov. is characterized by rather small body size (560–660 μm in males; 570–630 μm in females), short cephalic setae 2.5 μm long (21.4–31.3% of head diameter), spicules 65–85 μm (4.06–4.67 anal body diameter) and relatively simple gubernaculum. The two new species can be distinguished from other species of the genus by length and structure of spicules and gubernaculum. Pictorial and tabular keys to the genus are given.

Off central Chile, around 33.5°S, the freshwater discharge of the River Maipo generates a small- to intermediate-size plume, which moves up to the north driven by the daily sea breeze and with localized effects on a costal zone of about 10–15 km. The influence of this river plume motion on abundance patterns of larval barnacles was studied in a ∼12 km long transect, including 2–3 stations inside the river plume, one station on the visible turbidity front, and two stations outside the plume. Shipboard campaigns were conducted in January (summer), August (winter), and October 2003 (spring). On each occasion, conductivity–temperature–depth casts, bottom track acoustic Doppler current profiler current measurements, size-fractioned chlorophyll concentration, and stratified plankton sampling were conducted. A significantly higher abundance of barnacle nauplii was found at the river plume front than at the plume or outside the plume. Abundance was highest in the upper 10 m of the water column, where most nauplius larvae were found. The river plume appeared as a surface layer of less saline water moving north of the river mouth, with a buoyant frontal structure progressing at speeds of 5 to 20 cm s−1. Although no peak in chlorophyll was observed at the buoyant front, the highest concentration of effective prey size for feeding nauplii (chlorophyl-a <5 and 5–20 μm) was generally associated with less saline plume waters. Thus, the accumulation of barnacle larvae at the front may facilitate foraging, potentially increasing larval growth and energy reserves. Our results suggest that the spatial structure and temporal dynamics of river plumes should be considered by benthic ecologists as transport mechanisms that potentially affect larval delivery and settlement of barnacles on rocky shores.

A review of the shallow-water species of the genus Tryphosella from the British Isles is presented and a new species, Tryphosella lowryi, is described. In addition, Tryphosella minima is recorded from this region for the first time. This brings to five the total number of species of this genus now known from the British Isles. All taxa are fully described and illustrated, and a key to the species is provided.

In Malaysia, Indonesia and Polynesia, samples of algae and coral rubble were taken in order to collect the Amphipoda (Peracarida: Crustacea) inhabiting them. We report here on eight species: five from Indonesia (among which two are new to science, one Atlantic genus found for the first time in the tropics), one from Malaysia (reported there for the first time) and two were found from Moorea (one new to science, the taxonomic status of the other one not fully resolved).

Isolated embryonic membranes (i.e. the outer cuticular membrane, the fibrous layer, the inner cuticular membrane and the hatching membrane) of a bisexual and two parthenogenetic strains from South India were examined using sodium dodecyl-sulphate polyacrylamide gel electrophoresis. Interpopulation comparison of the protein patterns revealed variations in the major polypeptides between the three populations. Repeated analyses of the embryonic membrane protein pattern of the same population resulted in the same banding pattern suggesting that the method is reproducible. These differences might be used as markers for identification of different Artemia strains.

Marine reserves and restocking initiatives are sometimes used as a tool to enhance spiny lobster stocks. In such initiatives it is crucial to follow the movement of lobsters once they are released at sea in restocking experiments.

This paper presents the results of the application of an ultrasonic telemetry system to the monitoring of 11 lobsters (90±14 mm mean carapace length) released in the Capo Gallo-Isola delle Femmine Marine Reserve in north-western Sicily, central Mediterranean. The system comprised transmitters glued onto the lobster carapace, and manual as well as automated receivers to locate tagged animals. The data (i.e. number of detected signals) were tested to assess any difference in the diel activity of lobsters. The field study lasted 79 days in total. Lobsters remained in the study area for periods ranging from a few hours to the entire duration of the study. The longest distance travelled by a tagged lobster was 2.2 km. The number of signals varied significantly across the day, with the highest value recorded in the full-light hours (1000–1500), but they were not sufficient to assess clearly the diel activity of the released lobsters.

The interpretation of data suggests that: (1) released lobsters preferred a deeper habitat than that of the release site; and (2) the lobsters that reached a rough rocky area with available shelters settled there, while those that did not meet such a habitat soon moved out of hydrophone detecting range.