Community parameters of diatoms have been used as useful bioindicators for bioassessment of both lentic and lotic systems. The influence of enumeration time periods on detecting community parameters of periphytic diatom assemblages within different exposure times was studied using an artificial substratum in coastal waters of the Yellow Sea, northern China, during the period May–June 2010. Samples were collected at a depth of 1 m, and were examined with different enumeration time periods. Enumeration time periods represented a significant influence on detecting the community features of periphytic diatoms, although no significant changes occurred in periphytic diatom community structure between two enumeration schemes (within 24 h and 24–48 h). The delayed enumeration (within 24–48 h) may result in the similarity of the communities being reduced 10–29%, and in species numbers decreasing and in abundance increasing with exposure duration, respectively. The diversity (richness, evenness and diversity of species) indices were significantly decreased in almost all samples with >10% standard errors at some exposure times by the delayed enumeration scheme. These results suggest that the delayed enumeration may have resulted in the species richness and individual abundance of periphytic diatoms significantly decreasing and increasing, respectively, and thus significantly affected the analyses of species diversity for assessing water quality in marine ecosystems.

The patterns of decapod larvae occurrence and abundance were studied from weekly time-series data of 8 years from Stonehaven (north-east Scotland) and 4 years and 8 months from Loch Ewe (north-west Scotland). The annual cycle observed was similar in the two locations and characterized by abundance peaks, the first in spring and another in the summer, extending into autumn. During the coldest months (December to February) decapod larvae were virtually absent in the plankton. Differences in abundance and occurrence of decapod larvae between locations and the influence of temperature, salinity and chlorophyll-a in the patterns observed, were analysed by generalized least-square functions. The results showed significant differences in the abundance of decapod larvae between locations, with higher larval abundances and an earlier appearance in the plankton in Loch Ewe (west coast). In Stonehaven (east coast), from 2003 onwards, a general increasing trend in the abundance of decapod larvae was observed, related to the increasing temperatures recorded at that site. The data demonstrate the high variability of decapod larval abundance on an annual basis and the high importance of temperature and chlorophyll-a to the occurrence and abundance of decapod larvae.

The sandpaper skate, Bathyraja kincaidii, is one of four skate species commonly taken in trawl fisheries off central California although very little is known about its life history. In this study, age and growth were evaluated from 187 vertebrae using a common growth band counting method. An attempt to use marginal increment analysis and centrum edge analysis failed to validate the annual periodicity of growth band formation; however, it is a valid assumption based on structural similarity from other studies. Assuming annual band formation, von Bertalanffy growth parameters were determined for females (L∞ = 537.3 mm; k = 0.237; to = –1.629; N = 99) and males (L∞ = 580.2 mm; k = 0.185; to = –2.530; N = 88). Maximum likelihood ratios indicated no significant difference (P > 0.05) between male and female von Bertalanffy growth parameters, thus data were combined (L∞ = 557.8 mm; k = 0.207; to = –2.147; N = 187). Age estimates from band counts in vertebral centra indicated a minimum longevity of 17 and 18 years for female and male B. kincaidii, respectively. Caudal thorns were also assessed for age analyses, but were deemed unreliable and could not be used to verify age estimates from vertebral centra.

There is now much information from field observations and laboratory experiments on pollution by oil and oil-spill removers (‘detergents’) in inshore waters and littoral habitats in SW England following the wreck of the Torrey Canyon on the Seven Stones Reef. Field observations with particular reference to plant life were reported by O' Sullivan & Richardson (1967), Spooner (1967), Nelson-Smith (1967), and Bellamy et al. (1967). A detailed survey of the biological effects of the disaster has been published (Smith, 1968). Further data dealing with littoral and sublittoral algae have been reported by Ranwell (1968), Bellamy & Whittick (1968), Boney (1968) and Nelson-Smith (1968). It has been shown from both field observations and laboratory experiments that the larger fucoid algae were more tolerant of both the oil and the oil-spill removers than the smaller algae in the region of high-water mark.

1. Observations are given on the vertical distribution of Sagitta elegans and S. setosa in the daytime.

2. An account is given of the seasonal abundance of both species of Sagitta throughout the year as shown by collections made with oblique hauls with the 2-metre stramin ring-trawl and hauls with a bottom plankton net.

3. An attempt is made to piece together as much as possible of the life-stories and habits of Sagitta in offshore waters off Plymouth on the basis of these and previous observations.

For studying community structure and biodiversity of macrofauna, seasonal samplings were carried out along three different depths (5, 15 and 30 m) in four transects (12 stations) at Noor coast during 2005. Four higher taxa were determined. Polychaeta was the dominant group comprising 96.61 of the total individuals, followed by Bivalvia 1.35%, Oligochaeta 1.15% and Amphipoda 0.87%. Of the six encountered species, the polychaete, Streblospio gynobranchiata accounted for 84.95 of the total population. Also, Tubificoides fraseri was observed in the Caspian Sea for the first time. During this study, density of macrofauna increased with depths, total organic matter and percentage of silt–clay. The highest density was obtained in winter and the lowest was observed in summer. Maximum diversity, richness, and evenness were obtained, 0.91, 1.05 and 0.88, respectively. Also, multivariate analysis separated differences of density between seasons and depths.

Fatty acid profiles and carbon (δ13C) and nitrogen (δ15N) stable isotope markers were used to identify the diet of amphioxus in subtropical Hong Kong waters, and to evaluate the role of co-occurring Branchiostoma belcheri and B. malayanum in trophic transfer, in coastal ecosystems. The present results showed that while amphioxus is generally regarded as a filter feeder, total particulate matter in the water column might not be the main food supply. The diet of amphioxus could be traced to comprise a wide range of food sources, from microbes and microplankton to microalgae, based on the stable isotope analysis. Results of fatty acid profile analysis also revealed contributions from dinoflagellates, zooplankton, detritus and bacteria, and minor contribution from diatoms and fungi in the diet of amphioxus in Hong Kong waters. The use of fatty acid and stable isotope analyses further proved that amphioxus can, not only capture and partition such a different size-range of food particles during their feeding, but also assimilate most of them into their body tissue. The present findings suggested that amphioxus may play an important role in marine food webs by transferring microbial production to higher trophic levels through utilizing microbes in seawater as food.

The ormer, Haliotis tuberculata L. is a greatly prized species in the Channel Isles. Since the original survey of the ormer population of Guernsey and the subsequent tagging experiments (Forster, 1962, 1967), periodical short visits to the island have been made to investigate the stocks of ormers, especially in areas fished by divers; in 1968 and 1974 visits were also made to Jersey. These surveys were all made at the request of the local Sea Fisheries Committee. In this paper we seek to bring together those aspects of the results which are of scientific interest and to discuss the role of various factors which may have affected the ormer populations particularly that of changes in temperature over the last hundred years. The reproductive biology of this species has recently been reported on by Hayashi (1980).

Coral reefs have experienced extensive degradation across the world over the last 50 years as a result of a variety of stressors operating at a range of spatial and temporal scales. In order to assess whether declines are continuing, or if reefs are recovering, detailed baseline information is required from across wide spatial scales. Unfortunately, for some regions this information is not readily available, making future reef trajectories difficult to determine. Here we characterized the current benthic community state for coral reefs in the Wakatobi region of Indonesia, one of the most biodiverse marine regions in the world. We surveyed 10 reef sites (5, 10 and 15 m depth) to explore spatial variation in coral reef benthic communities and provide a detailed baseline. Previous data (2002–2011) were available for coral, sponges, algae and soft coral at six of our study sites. Using this information, we determined if any changes had occurred in dominance of these benthic groups. We found that benthic assemblage composition differed significantly over relatively small spatial scales (2–10 km) and hard coral cover was highly variable, ranging from 7–48% (average 19.5% ± 1.5 SE). While coral cover appears to have declined at all sites where data were available since 2002, we found little evidence for widespread increases in other benthic groups or regime shifts. Our study provides a comprehensive baseline dataset for the region that can be used in the future to determine rates of change in benthic communities.

Euryhaline fishes, such as the salmon and the eel, adapt the osmoregulatory mechanisms of their gills, kidney and intestine so that they retain water while they are in the sea but retain salt while in fresh water (e.g. Krogh, 1939). Thus on entering fresh water the osmotic pressure of plasma in the Atlantic salmon, Salmo salar L., only falls from some 410 m-osmole/1 to about 340 m-osmole/1 (calculated from the freezing point data of Benditt, Morrison & Irving, 1941), although the osmotic pressure of the environment falls from around 1000 m-osmole/1 to almost zero.

The published records of the occurrence of the Devonshire Cup Coral Caryophyllia smithii Stokes and Broderip in Scottish waters are widely scattered throughout the literature. Rees (1962, 1966) listed several of these and suggested that the paucity of records was a reflexion of the comparatively little systematic collecting that had been done on the Scottish coasts and on the continental shelf.

The purpose of the present paper is to collate and review the published records of the distribution of C. smithii and to present new data derived from extensive investigations carried out by the Institute of Oceanographic Sciences, Wormley, as part of a study of shelly faunas and sediments on the continental shelf west and north of Scotland. Additional records obtained from several other sources are also included.

Three new species of Fritillaria are described from specimens collected by a remotely operated vehicle (ROV) between 180 and 735 m depth in Monterey Bay, California. Fritillaria rex becomes the largest species now described for this genus (trunk length up to 10 mm, tail length up to 18 mm). This species is characterized by five or six narrow muscle bundles on each side of the tail, slit-shaped spiracles, a spherical ovary and a cylindrical testis. Fritillaria amphigonadis (trunk length up to 5.2 mm, tail length up to 7.5 mm) is characterized by two narrow muscle bundles on each side of the tail, slit-shaped spiracles, paired spherical ovaries, and a unique pi-shaped testis. Fritillaria lucifer (trunk length up to 4.1 mm, tail length up to 7.0 mm) has 12 extremely thin muscle bundles distributed broadly across the tail, rounded spiracles, a spherical ovary and a U-shaped testis. An additional mesopelagic Fritillaria appears to be consistent with the description of the Mediterranean F. fage, but specific differences in pharyngeal cells, cellular patterns on the tail, and gonadal morphology suggest that the specimens from Monterey Bay are a new variety, F. fagei mbarii. Based on the relatively limited number of collections (i.e. only 20 specimens yielding four unique taxa), it would appear that the possible diversity of larvaceans that live below the surface mixed layer is significantly underestimated.

It is only within comparatively recent times that it has been proved that the otoliths and scales of certain Teleostean fish can be used for the determination of their age.

Rings of growth, as they are called, are produced on these structures, and it is by counting the number that the age is ascertained, in much the same way as the approximate age of a tree may be determined by counting the annual rings.

Most fertile individuals of the apodid sea cucumber Polycheira rufescens, living in the intertidal zone near Iso Marine Station in southern Kyushu, Japan, spawned on day one and two before every full and new moon in the period from the second half of July until August or October from 1983 to 1989, the month differing in different years. Synchronous spawning associated with the same phases of the moon was also observed at Sakurajima Marine Station near Iso in 1991. Individuals ready to spawn were divided into four sexual types: two sorts of hermaphroditic males with small or larger growing oocytes and males and females. Further investigation revealed that some individuals changed from male to female or from female back to male in the two week interval between spawnings. Moreover synchronous gametogenesis occurred in association with sex changes throughout the breeding season, the period from initiation of spermatogonia proliferation to spermatozoa release was three weeks, and the period from initiation of oocyte growth to egg shedding was about five weeks.

The oceanic scyphomedusa Pelagia noctiluca (Forskål) was exceptionally abundant in the coastal waters of Devon and Cornwall in the year 1966. Very young stages were taken only in the months of October, December, January and early February, indicating that the medusa has a restricted breeding season.

Spatial distribution patterns of microzooplankton (0.055–0.3 mm) biomass and abundance were studied in relation to the hydrographic situation and the local flow field in the waters off Ampère and Senghor, two shallow seamounts in the subtropical and tropical NE Atlantic, in comparison with unaffected open ocean reference sites. Ampère was sampled during November/December 2010 and Senghor during December 2011 and February 2013. The study includes taxonomic composition, abundance of meroplanktonic larvae and an estimation of the respiratory carbon demand. Biomass (dry weight) standing stocks of microzooplankton in the upper 100 m ranged between 30–120 mg m−2 over Ampère and 140–260 mg m−2 over Senghor Seamount, corresponding to 33 and 24% of the total zooplankton (0.055–20 mm). Highest total abundance was always found in the upper 50 m with numbers of 1070–5060 Ind m−3 at Ampère and 5050–20,000 Ind m−3 at Senghor with microzooplankton contributing 70–95%. Zooplankton accumulated mainly at the thermocline coincident with the deep fluorescence maximum and was ascertained by food supply rather than by oxygen limitation. The microzooplankton contribution to the total respiratory carbon demand was ~50% in the subtropical waters off Ampère and ~30% at Senghor, reflecting the important role of microzooplankton in the waters of the NE Atlantic subtropical gyre. Clear evidence of local seamount effects resulting in enhanced microzooplankton biomass compared with the unaffected reference sites were not detected. However, we confirmed Senghor as a hotspot for meroplanktonic larvae, suggesting a retention potential that results in significantly enhanced larval abundance in the seamount waters as compared with the open ocean.

Flounders grew much more slowly in 1944 than during the previous 2 years. From October 1943 to October 1944 their mean size increased from 7·9 cm., 6·8 g., to 12·7 cm., 23·6 g., an increment which was if anything smaller than under normal conditions. The reason for the reduction in growth rate is attributed to the increasingly unfavourable hydrographic conditions resulting from the prolonged closure of the dam, in particular to the high H2S concentration, the high pH and the low oxygen concentration of the water.

In the autumn of 1944 the sluice gate of the dam was opened for several months. In 1945/46 the growth of stock III flounders was very rapid. They reached a mean size of 32·3 cm., 409 g., in March 1946 and 36·8 cm., 580 g., in March/April 1947. Native flounders reached a mean size of 30·6 cm., 353 g., in 2 years.

The present work reports the existence of extended parental care in a hermit crab species of the genus Calcinus. The species shows a high energetic investment in egg production, only producing one to six large-sized eggs. The larval development is extremely abbreviated, with the larvae hatching at an advanced zoeal stage, a rather uncommon feature among marine and non-symbiotic decapods. The sequential moults end in a glaucothoe-type larval stage that is retained inside the female's host gastropod shell, probably in complete lecithotrophy. The high maternal reproductive investment displayed by this species is certainly maximized through the retention of juveniles until they enter a suitable gastropod shell, since it considerably reduces the chances of intra- or interspecific predation.

Of the three species of the genus Squalus that occur in the Mediterranean Sea, S. blainville and S. megalops are very difficult to distinguish. This study assesses the variability in morphological features that have been used to differentiate between these species. Squalus were collected from stations within the 25-nautical mile Fisheries Management Zone around the Maltese Islands; 349 specimens were dissected and categorized into male and female, mature and immature, and individuals were randomly selected from each category to make up a sample of 169 specimens. For each individual, total length and first dorsal fin parameters were measured, and morphology of denticles isolated from the laterodorsal area, of the upper and lower teeth and of the chondrocranium was analysed. The first dorsal spine was shorter that the fin base in 93% of the specimens, which is typical of S. megalops; this character was not related to either gender or maturity. Chondrocrania with one lateral process (typical of S. blainville) and two lateral processes (typical of S. megalops) were present. Teeth from the same individuals showed morphological features that overlap between S. blainville and S. megalops. Both unicuspid (typical of S. megalops) and tricuspid denticles (typical of S. blainville) were observed on the same individuals. Twelve specimens (six having one and six having two lateral chondrocranial processes) were analysed genetically by sequencing of the mtDNA marker Cytochrome Oxidase Subunit I (COI). All resulted to be S. blainville showing that intraspecific variability in supposedly diagnostic morphological features is large enough to render these unreliable to tell apart these two species, especially in the field.