Three species of Gracilaria, G. foliifera (Forsk.) Børg., G. verrucosa (Huds.) Papenf., and G. bursa-pastoris (S. M. Gmel.) Silva are recognized from the British flora (Parke & Dixon, 1976). In Britain G. verrucosa is widely distributed, although not common, whereas the other two species are rare and their distribution restricted (Newton, 1931). G. foliifera was described from the Red Sea as Fucus foliifer Forsk. (Børgesen, 1932). Plants referable to this species are now reported from various parts of the world, including both the eastern and western coasts of the north Atlantic (South & Cardinal, 1970; Taylor, 1957, 1960). However, considerable variation exists within species of Gracilaria (e.g. May, 1948), thus delimitation of species is often extremely difficult. Gracilaria foliifera from Britain (Fig. 1 A) is similar morphologically to the original material of Fucus foliifer as illustrated by Børgesen (1932, fig. 1), and therefore, we have limited our consideration to G. foliifera as it occurs in Britain (also see Harvey, 1846, pl. 15). However, little information is available on G. foliifera from the British Isles, and in the present instance we have investigated the life history of this alga in culture together with preliminary results on growth in small-scale tanks with running sea water.

Some understanding of the mechanisms involved in the development and maintenance of forests of Laminaria hyperborea (Gunn.) Fosl. can be gained from the analysis of populations under different conditions. The main variable is depth and unfortunately the available depth range of suitable substrata in the Isle of Man is limited. For this reason two visits were made to western Scotland and the Outer Hebrides, in 1970 and 1976. This paper, which is intended as the last in this series, reports on results obtained rom there and from certain sites in the Isle of Man.

In the Galway Bay area the carragheen species, Chondrus crispus Stackh. and Gigartina stellata (Stackh.) Batt., are still collected using traditional methods. The weeds are picked by hand, spread out on any convenient area of grass, allowed to dry and, in the case of Chondrus, bleach in the open air. Most collecting is done during the autumnal equinoctial spring tides and is virtually restricted to the intertidal zone.

The Irish seaweed industry has declined since 1960, when according to Chapman (1970) production reached its peak. When describing the industry in 1974, Cahill & Sweeney made the following comments. ‘A small number of firms are engaged in harvesting and primary processing. Between 1000 and 1250 people are seasonally employed. Almost 40000 tons of wet weed are harvested annually with a landed value of approximately £200000. Harvesting techniques are largely manual and there is a possibility that the industry may decline in the medium term as alternative and more lucrative employment opportunities become available.’

In his search for evidence illustrating the botanical/zoological affinities of the sponges (Porifera), James-Clark (1867) studied a number of colourless flagellates. The genus Salpingoeca (Craspedophyceae, Christensen, 1962; cf. Chadefaud, 1960) was thus erected to comprise certain solitary, lorica-dwelling organisms, characterized by a single anterior flagellum encircled by a ‘filmy, membranous, colourless collar’ (James-Clark, 1867).

About fifty species (approximately twenty marine) are at present allocated to this genus, provided it is defined as e.g. by Norris (1965) and Bourrelly (1968) (i.e. including Lagenoeca Kent and Pachysoeca Ellis).

Earlier studies on the problems of the Adriatic Sea and the knowledge of its hydromedusae are restricted to the northern part. Will (1844) mentioned six species of hydromedusae found in the Bay of Trieste. Several studies ensued from the northern part of this sea, until Neppi (1912, 1915, 1922), Pell (1911, 1938), Kramp (1924), Babnik (1948) and Benović (1971 a) included other areas. Some specimens from the middle and southern Adriatic are mentioned in the planktonic works of Gamulin (1948, 1976), Hure (1955, 1961), Buljan, Hure & Pucher-Petković (1973) and Vučetić (1957, 1961, 1966).

Many workers have considered the possibility of hydroids being potentially somatically immortal, largely because of the continued production of interstitial cells which can differentiate and migrate to replace cells in other parts of the hydroid (Schmid, Schmid & Tardent, 1974). In addition, many thecate hydroids show an orderly regression and replacement of their hydranths (see review by Toth, 1969) and this led Crowell (1953) to suggest that by this means hydroids might avoid senescence. Such considerations are undoubtedly fostered by the lack of evidence for senescence of hydroids which, although sometimes showing a cycle of degeneration followed by regrowth from a dormant stolon, may live for many years in the laboratory (Strehler, 1961; Brock, 1974). Only recently has the senescent death of a hydroid (Corymorpha nutants (L.)) been recorded (Svoboda, 1973).

Idotea pelagica Leach is typically found on exposed shores among barnacles and stunted fucoid algae. It has been recorded from Norway to the coast of France, excluding the low salinity waters of the inner Baltic (Naylor, 1972). Studies have been made of its feeding (Naylor, 1955a), external morphology (Naylor, 1955 b) and ecological distribution (Naylor, 1955 c).

Studies of tissue metal concentrations in shellfish have progressed along two major lines: first, to record the range of concentrations within commercial species, a response to the need to identify potentially hazardous levels from a human nutritional standpoint; and second, to compare concentrations within a single species on a geographical basis as a framework for an environmental monitoring programme. Body size is a parameter which can influence tissue metal concentrations, and if significant variations due to size do occur, then clearly it is a factor which should be taken into consideration within these contexts.

Although anaesthetic techniques are well established for most of the vertebrates, methods for the invertebrates are generally not well documented. The decapod Crustacea are widely used for neurophysiological studies involving the implant of chronic electrodes and other techniques. With sluggish species such as Cancer pagurus some workers simply give the animal an object to grasp and perform their operations in the unanaesthetized condition. Others use hypothermia to immobilize their animals, although this may result in autotomy of appendages. Other methods include immersion in solutions of ethanol, magnesium salts (Pantin, 1946), or carbon dioxide. Conventional aquatic vertebrate anaesthetics such as MS-222 (Sandoz) are generally ineffective by immersion in decapods. This short investigation has set out to find out if a suitable anaesthetic drug is available for experimental work and for live dissections.

Analyses of the relationship between the size and the number of eggs per female in various decapods, isopods, cumaceans and mysids were made by Jensen (1958) based upon personal research and information from available literature. Regression analyses indicated that the number of eggs per female is related to the cube of the body length.

The ciliates are considered to be the dominant protozoan group in the lacunar system of marine sediments and the important role which they play in the benthic ecosystem has been emphasized (Fenchel, 1969). More than 7500 ciliate species have been described (Corliss, 1974 a) and their distribution is worldwide (Agamaliev, 1967 a; Burkovsky, 1970c; Dragesco, 1960, 1965a; Kahl, 1930–35; Petran, 1967; Raikov, 1962). However, only two surveys of the interstitial ciliates of the British Isles have been carried out (El Maghraby & Perkins, 1956; Lackey & Lackey, 1963). This paper describes a study of the systematics and ecology of interstitial ciliates of the North Yorkshire coast.

In February 1965 larvae of Sabellaria spinulosa Leuckart removed from the plankton off Plymouth were reared for settlement experiments (Wilson, 1970b). Among the early stages in the rearing dishes there appeared several Sabellarian-type larvae which after a few days growth became conspicuous by their larger size, longer and straighter bristles, and by their general appearance being different from the more numerous Sabellaria larvae. It soon became apparent that they closely resembled a larva found in February 1927 which was described and illustrated many years ago (Wilson, 1929, p. 242, text figs. 4, 5), at which time it was attributed in all probability to Pallasia murata Allen, now Lygdamis muratus (Allen). Apart from two species of Sabellaria whose larvae were known, this was and still is the only other Sabellarian recorded from the coasts of Devon and Cornwall and adjacent offshore waters of the English Channel. In most years since 1965 varying numbers of this species of larva have been obtained in January and February, and have several times been reared through metamorphosis to early tube-building stages, these latter confirming by their distinctive characters that the above early attribution was correct. Work on a description of the development was begun but it was not until 1974, when work on colony formation of Sabellaria alveolata (L.) was virtually completed, that close attention could be given to it, and experiments on settlement carried out. In the meantime Bhaud (1969) had described and illustrated the development from larvae in winter plankton off Banyuls-sur-Mer, wrongly attributing them to Phalacrostemma cidariophilum Maranzella, while criticizing my identification of my 1927 larva.

In an attempt to identify the causes of the natural population fluctuations on British rocky coasts, an exploratory programme on the recruitment fluctuations of certain ‘key species’ has been operating for several years. The choice of species and the emphasis upon their recruitment have been discussed elsewhere (Lewis, 1976) and were justified as the most economical means of gaining the ability to (a) ‘explain’ major changes in the general character of rocky shore communities, and (b) make predictions about natural events against which to detect regional or temporal consequences of man-made changes in water quality. Mussels, barnacles and limpets are being studied but it is the last with which most interpretative progress appears to have been made, and this paper is concerned solely with Patella vulgata L. It is, however, essentially a preliminary report in a continuing study and it illustrates the practical and interpretative problems inherent in formulating and substantiating hypotheses in this type of work.

As Moseley (1879) noted, it may be imprudent to assume there must always be a ‘reason’ for observed displays of bioluminescence. However, knowledge of the colour of the light emitted may be useful for examining some of the theories about the function of marine bioluminescence. Certainly the colour of the light is important in predicting the rate of its attenuation in sea water, and the ease of perception of the light by the organism itself, or by potential predators, prey, or mates. In addition, the colour of the light may indicate something about the compounds responsible for producing the light. The present paper presents some bioluminescent emission spectra of freshly caught organisms from the Sargasso Sea.

The oceanic sunfish Mola mola is occasionally found close to our shores, its normal habitat being the oceans throughout the world. It is replaced by Mola ramsayi only in the South Pacific (Fraser-Brunner, 1951). Specimens which are caught around the British Isles normally come from the North Atlantic as a result of being washed inshore when the warm westerly winds are blowing during the summer.

Although the initial description of the northern rockling, Ciliata septentrionalis (Collett, 1875 a, b) was based on specimens collected off the Norwegian coast in the late nineteenth century, this species was not recorded from British waters until 1960, when a specimen was found in the Clyde Sea area (Bagenal, 1961). Subsequently, northern rockling have been recorded by Wheeler (1965, 1968) from the Moray Firth and in the waters off the Isle of Man and Southern Ireland, and by Dando (1975) from the Plymouth area. A single specimen has also been captured in a rock pool on the Yorkshire coast (Wheeler, 1971). The only investigation into the biology of C. septentrionalis has been conducted by Dando (1975), who obtained the fish from the Plymouth area, both by trawling and from cod stomachs. He outlined the early development of the egg and larva, and suggested that the northern rockling had greatly increased in abundance in the Plymouth region since 1968.

The importance of egg and larval mortality in the determination of year-class strength was discussed at a colloquium at La Jolla, California in 1975 (see Hunter, 1976). In addition to the obvious effects of starvation, predation and disease, pollution by such substances as copper is an important factor affecting viability. The copper concentration in sea water is generally about 1–2,µ/l. Chester & Stoner (1974), in a comprehensive survey, found an average copper concentration of 0.8µ/l in the open ocean and 0.9 µg/l nearer the shore. In British waters Preston et al. (1974) reported a range of 1.1–1.6 µg/l and Portmann (1972a) found a range of 1–20 µg/l with the possibility of 1000 µg/l near sea-bed copper deposits.

It has been possible for some years to rear artificially-fertilized herring eggs through to metamorphosis making experimental studies on the larval phase of the life history practicable (Blaxter, 1968). However, a comprehensive larval staging system has not previously been published.

Radioactive wastes and sewage discharged into coastal waters may be largely dispersed by tidal streams. Before authorization for sea discharges can be granted by responsible authorities representing public interests, as much information as possible must be obtained on water movement in the chosen area. Comprehensive data on tidal conditions around the British Isles can be found from the Admiralty Tidal Stream Atlases (Hydrographic Department). The method by which these currents are measured is explained in the Admiralty Manual of Hydrographic Surveying (Hydrographic Department, 1948). Further, special surveys using sea surface drifters and current meters are usually necessary to provide additional information in the neighbourhood of a proposed release. The purpose of this note is to point out that further relevant information can be obtained using numerical models and that these results should also be taken into account when decisions have to be made.

During studies in 1972 on the setation and development of the secondary sexual characters of the Norway lobster, Nephrops norvegicus (L., 1758), Foraminifera were observed attached to the pleopods of a mature male (carapace length 2.47 cm). On subsequent examination of the prepared material with a scanning electron microscope it was found that the Foraminifera were attached to one of the first pair of pleopods. Three individuals were observed, all of which were attached to the same pleopod on the inner surface near the tip. No further specimens of Foraminifera were encountered during detailed anatomical studies of more than 30 specimens of N. norvegicus.