By the death on 14 December of Professor Sir James Gray, K.T., C.B.E., M.C., Criox de Guerre, M.A., Sc.D., LL.D., F.R.S., at the age of 84, both zoology and marine biology have lost one of their great figures. His connexion with the Marine Biological Association of the United Kingdom stretches from his first visit as a research worker to the Plymouth Laboratory in 1912, when he became a member of the Association, through his long service on the Council (first in 1920 and then continuously from 1928 to 1969), to his Presidency (1945–55) and his election as Vice-President in 1955 and Honorary Member in 1965. He was also a member of the Scottish M.B.A. since 1921 and served on its Council for six years (1960–66) and was elected a Vice-President in 1965.

The Preliminary Check-list of British Marine Algae (Parke, 1953), with three subsequent lists of additions and corrections (Parke, 1956,1957,1959), was superseded by the Revised Check-list of British Marine Algae (Parke & Dixon, 1964) and the Check-list of British Marine Algae - Second Revision (Parke & Dixon, 1968). Since the publication of the 1968 list, changes, both taxonomic and systematic, have been sufficiently numerous to warrant the present list incorporating further additions, corrections and emendations.

INTRODUCTION

Pavlova gyrans Butcher, the type species of the genus, was described at the light microscope level in 1952 (Butcher, 1952). Since then this species has been re-investigated with the electron microscope (Green & Manton, 1970), a number of other species described from marine, brackish and freshwater habitats (for literature, see p. 600) and at least two new genera erected which appear to be closely related to Pavlova (Corcontochrysis Kalina, 1970;Exanthemachrysis Lepailleur, 1970).

INTRODUCTION

In the genus Laminaria the origin of the growth of the frond (blade, lamina) is known to be the meristematic transition zone between frond and stipe. Parke (1948) showed, by observing holes punched in the frond, that the fastest rate of growth in length in L. saccharina (L.) Lamour. was in the proximal 25 mm. However, during measurements of the rate of growth of fronds of plants of known age on previously cleared areas (Kain, 1976), it was noted that in L. hyperborea (Gunn.) Fosl. the maximum rate of elongation occurred at some distance from the transition zone. This led to an investigation of the whole pattern of growth, in terms of elongation, increase in area, decrease in thickness and change in cell size and numbers over the surface of the frond at different stages.

INTRODUCTION

A comparative survey on the capacity of several nitrogenous compounds to support marine phytoplankton growth showed urea as the best and D-glucosamine as the poorest supplier of organic-nitrogen at a concentration of 500 /g-at. N per litre (Antia et al., 1975a). The quality and degree of growth on glucosamine was always so inferior that the evidence appeared insufficient to establish whether this compound was actually being metabolized by the algae. By analogy with the substrate-utilization kinetics reported for growth of other micro-organisms such as yeast (e.g. Tseng & Wayman, 1975), the probability was considered that the glucosamine concentration used in the above survey may have been too low for adequate uptake under the test conditions chosen and that elevated concentrations, in facilitating such uptake, may provide unequivocal evidence of algal capacity for metabolism and utilization of this substrate. However, such concentration elevation would require to be below levels that may become inhibitory to growth, and these inhibitory levels may themselves vary from one species to another. Antia & Chorney (1968) reported 5 mM glucosamine to be toxic to growth of the cryptomonad Hemiselmis virescens, whereas McLachlan & Craigie (1966) observed growth of the diatoms Cyclotella cryptica and Thalassiosira fluviatilis on five times this level of concentration.

Direct measurement of water loss from isolated podia of Luidia ciliaris under the influence of known levels of hydrostatic pressure has yielded a revised value for the permeability of this structure to water, namely 37.4 x 10-8 cm3/cm2.s.cm H2O pressure. The total fluid loss from a 50 g starfish will therefore be of the order of 0.75 ml/h. The mechanism for the replenishment of this fluid is discussed in the light of the traditional role of the madreporite. It would seem that adequate influx of fluid through this structure has not been observed, neither could it be responsible for ‘topping up’ in the case of arms severed from the parent body which still continue to move for considerable periods.

INTRODUCTION

Dodecaceria caulleryi breeds asexually by fragmentation and regeneration (schizogenesis), and sexually as an epitoke. Fragmentation is initiated in September-November in worms generally more than 40 segments long with the autotomy of the anterior 11–34 segments. Some 14–18 isolated segments are then autotomized in succession from the front of the remainder of the worm, leaving a residual 7–19 posterior segments. The anterior, individual segmental, and posterior fragments produced in this way all begin regenerating; anterior regeneration of the posterior fragment is limited to 14 or fewer segments but posterior regeneration and growth of all fragments is unlimited though slow. When the segmental fragment has regenerated about 7 new anterior and posterior segments, these may be autotomized as secondary individuals and the original segment regenerates again. The anterior regenerate is more commonly shed than the posterior regenerate and not all segmental individuals engage in secondary fragmentation.

INTRODUCTION

The copepod Temora longicornis Miiller is one of the common zooplankton species in the North Sea and adjacent waters. All developmental stages have been recorded throughout the year off the west coast of Sweden, Temora being considered more common in offshore than inshore waters (Eriksson, 1973). In Loch Striven on the west coast of Scotland it was abundant only in summer, living mainly near the surface (Marshall, 1949). Similarly in the English Channel off Plymouth Temora is present mainly during the summer months (Digby, 1950). T. longicornis was found throughout the year in the Northfrisian Waddensea with temperatures ranging from ca. 1–20 °C (K¨nne, 1952).

INTRODUCTION

During the last 25 years I have collected opisthobranchs from more than 1200 stations (dredgings, collecting by divers, visits on the tides etc.) all around the Northern Atlantic, and among them close to 200 from the British Isles, viz. during two short visits to Plymouth, two somewhat longer ones to Menai Straits, one to Millport in Scotland, and three to Carna in W. Eire. In all those places, the respective marine stations, leaders and personnel, have been of the utmost help and assistance, and I hereby express my warmest appreciation for the kind way in which I have been received. Without that strong support I should never have been able to accomplish the task of comparing live specimens of opisthobranchs from all around the Northern Atlantic in order to tackle all the taxonomic problems involved. The present paper on the genus Doto is my first separate contribution to a revision of the British nudibranchs. The material obtained is kept in the Zoological Museum of the University of Copenhagen.

INTRODUCTION

The ommastrephid squids are large active animals occurring in most of the world's oceans. Luminous organs or bioluminescence have been observed only in members of the subfamily Sthenoteuthinae, containing the genera Ornithoteuthis, Symplectoteuthis (= Eucleoteuthis), Hyaloteuthis, Ommastrephes and Dosidicus. The light organs of Ommastrephes pteropus are small sub-spherical bodies randomly distributed over the ventral surface of the mantle, head, arms and tentacles (Roper, 1963) and are aggregated dorsally to form a large luminous patch (Clarke, 1965). Relatively little is known about the organs, capabilities and biochemistry of luminescence in cephalopods (Harvey, 1952; Herring, in Press), and the size of the light organ and availability of O. pteropus provide an unusual opportunity for such studies. Although among the molluscs the luminescent systems of the gastropod Latia and the bivalve Pholas have been partially characterized (Shimomura & Johnson, 1968; Henry, Isambert & Michelson, 1970, 1973) the only cephalopod system which has been investigated to date is that of the enoploteuthid Watasenia scintillans (Goto et al., 1974; Inoue et al., 1975). This investigation examines the anatomy and biochemistry of the dorsal light organ of O. pteropus, which differs markedly in these respects from the brachial organs of Watasenia.

INTRODUCTION

Molluscan age determination has long been the subject of both biological and paleonto-logical research (Mossop, 1922 a, b; Haskin, 1954; Merrill, Posgay & Nichy, 1965; Andrews, 1972). Several workers have listed difficulties associated with traditional methods of determining the age of an organism based upon surface shell morphology (Pannella & MacClintock, 1968; Farrow, 1971, 1972; Berry, 1971). Others, such as Craig & Hallum (1963) have attempted, with moderate success, to circumvent these problems statistically by using size-frequency relationships, but such methods are of little value in age analysis of isolated individuals. The principal difficulty encountered in shell surface analyses arises from an inability to distinguish spawning and disturbance lines from annual marks. Problems associated with this separation have been reduced over the past decade by the discovery of daily and tidal periodicity structures within the shells of numerous Recent and fossil species of pelecypods (Barker, 1964,1970; Pannella & MacClintock, 1968; Clark, 1968; House & Farrow, 1968; Farrow, 1971, 1972). The biological and paleontological significance of such growth increments have been discussed at length by Pannella & MacClintock (1968), Barker (1970), and Clark (1974). When present in continuous sequences, these periodicity structures facilitate an accurate age determination of individual specimens.

INTRODUCTION

This analysis of cephalopod remains, particularly the mandibles or beaks, from sperm whales caught off Iceland is one of a series made by the authors on remains from various geographical regions including Madeira (Clarke, 1962a), Spain (Clarke & MacLeod, 1974), Western South America (Clarke, MacLeod & Paliza, 1976, South Africa, Western Australia, the Antarctic and the South Atlantic (Clarke, 1976, 1977). Other workers have described similar collections from New Zealand (Gaskell & Cawthorne, 1967; see also Clarke, 1976, 1977) and the North Pacific (Akimushkin, 1954; Betesheva & Akimushkin, 1955; Tarasevich, 1963). The present analysis has depended upon a development in the technique of identification of cephalopod lower beaks from an early search for criteria (Clarke, 19626) to a point where many species can be identified from lower beaks (Mangold & Fioroni, 1966; Iversen & Pinkas, 1971; Clarke, 1977).

INTRODUCTION

Ascidian tadpoles are short-lived, actively swimming larvae. On attachment to their preferred substrates they absorb the tail, and with it all their locomotory equipment. The behaviour is in general geared to the short-term problems of dispersion and settlement (Crisp & Ghobashy, 1971).

The small size of these tadpoles (2 mm in Dendrodoa grossularia, van Beneden, the species used) makes them difficult to handle. Surgical operations on the nervous system (Kasas, 1940), such as we were able to perform on the tadpole-like but larger Oikopleura (Bone & Mackie, 1975) are scarcely feasible here. Nevertheless, it is desirable to know more about the tadpoles’ locomotory organization if only because their possession of the chordate type of locomotory equipment raises interesting questions concerning possible functional parallels and evolutionary origins.

INTRODUCTION

During the production of china clay, a waste of fine quartz, sand kaolin and mica flakes in suspension is produced. Until recently, only a small proportion of this fine material was retained and settled in lagoons and consequently most of the effluent was discharged. Waste produced in the St Austell area was carried by the Par and White Rivers into Mevagissey Bay (see Fig. 1). In 1968 the china clay industry considered a proposal to combine all its wastes arising in the area and to discharge them into the sea via the White River or if necessary further out to sea by a pipeline. The precise location of the pipeline was not denned at that time but, irrespective of position, deterioration of conditions in St Austell and Mevagissey Bays seemed inevitable.

INTRODUCTION

Several authors (Cable & Hunninen, 1942; Dogiel, Petrushevski & Polyanski, 1958) noted that fishes while being kept in aquaria, lose the intestinal parasites with which they had become infested in nature. Up to now no quantitative examinations have been made on this subject. A better knowledge of the behaviour of parasites of fish in captivity seems to be of interest for several reasons.

The possible elimination of intestinal parasites by quarantining the host fish would be of importance in case of parasites which are able to complete their life-cycle in the aquarium and which might provoke mass-infection.

INTRODUCTION

In earlier papers (Allen, Blaxter & Denton, 1976; Blaxter & Denton, 1976) an account was given of the development and structure of the swimbladder-bulla-lateral line system of the herring Clupea harengus L. and sprat Clupea sprattus (L.) and its function in the larval stage. In this paper we describe experiments on juveniles of these species in which the system is fully developed.