The writer has recently reared a species of hydroid at Plymouth, which, in the vegetative state, might easily be confused with Slauridium productum Wright, 1858. The original creeping stolon from which the colony developed was found on a piece of dead Eunicella verrucosa (Pallas) dredged by the S.S.Salpa near Stoke Point on March 9th, 1936.

When isolated in a finger-bowl with “outside” sea water the stolon bore no polyps and showed no sign of activity, but three weeks later a single polyp had developed (Fig. 3). From its close resemblance to the figures given by Hartlaub (1895) for S. productum, it was at first assumed to be this species and was carefully watched and fed in the hope of rearing the medusæ from it. After a period of time, however, when the colony had increased considerably in size, styloid gonophores were developed.

The type of growth of the fully grown colony is shown in Figures 1 and 2. The stems are elongated and slender, bearing polyps at intervals. Polyps are borne at the summit and also on branches of the main stems. These branches usually arise from one side only of the main stems and it is probable that under natural conditions in the sea these main stems are really stolons. It is also likely that in nature the intervals between the polyps are fairly short. The whole colony has a faint yellow-brown colour which becomes reddish-brown in the polyps and the upper part of the hydrocaulus.

Leptoclinides faeröensis Bjerkan (1905) is a little-known boreal species which has been found only in the Atlantic Ocean (Fig. I). The most northerly record is from a little south of Spitzbergen, the most southerly from 37° 08' N., off the North American coast. It occurs on the coast of Norway and in the Faeroe Islands, but it has not been reported nearer to Plymouth than these two localities. Most records are from deepish waters, though it occurs in the sublittoral zone along the Norwegian coast. It was in this zone, at Looe Island (50' 20' 24“ N., 4 °26' 53” W.) near Plymouth, that we found a specimen of this species growing on a rock about 80 cm. below O.D.—just sufficiently low for it to remain covered by a few centimetres of water at the lowest tide of the year, the equinoctial spring tide.

When Michaelsen (1923) described a species of didemnid from Heligoland, he stated that it was very similar to Leptoclinum maculosum Milne Edwards (1841), so far as may be judged by external appearance, but since no adequate description of this latter existed he proposed to call his Heligoland form by a new name, Didemnum helgolandicum, rather than use an old name which might well be wrong. Neither Michaelsen nor Hartmeyer, who described further details of D. helgolandicum (1924), was able to compare it directly with specimens of D. maculosum from the Channel coasts whence it was first described by Milne Edwards. Through the kindness of the directors of the Zoological Museum of Copenhagen and of the Biological Station of Roscoff I have been able to obtain specimens of both these forms and to compare them with specimens collected around Plymouth and on the coast of North Wales, and with specimens of D. candidum Savigny, collected at Naples, and from the Red Sea, and of Trididemnum alleni Berrill, collected around Plymouth.

In the undisturbed sea urchin embryo, cleavage of the blastomeres is invariant and gives rise to five polyclonal territories that are each defined by the larval structures to which they give rise, and by unique programmes of gene expression. These territories are the aboral ectoderm, the oral ectoderm, the vegetal plate, the skeletogenic mesenchyme, and the small micromeres. Structural gene markers for four of these territories (all except the small micromeres, which participate in later development) have been cloned and characterized, and the regulatory domains of several of these genes have been mapped to the level of specific protein-binding sites.

Microphytobenthos (MPB) contributes up to half the primary production of estuaries. These microorganisms are sensitive to changes in sediment temperatures, particularly the extreme temperatures during exposure periods. This study investigates the physiological responses of MPB to freezing temperatures at two locations near Hobart, Tasmania during winter. Photosynthetic parameters were measured at 2 mm intervals to a depth of 10 mm. FV/FM values at three different distances from the shoreline at Kings Beach and Browns River in winter were between 0.584 and 0.617. rETRmax values were between 24.696 and 20.773. Maximum α values peaked in the subsurface rather than at the sediment surface. In vitro laboratory experiments (down to −5°C) showed little difference in response between the control and treatment groups, indicating no apparent effects of short term freezing on the MPB. Little change in photosynthetic parameters in response to freezing was probably associated with the resistance of light-harvesting reactions to freezing temperatures, recovery of the plasmalemma integrity or cryoprotection. Sediment composition and species composition were similar at both sampling sites. Therefore, responses of MPB were not due to species and grain size composition.

In 1902 Ernst Vanhöffen drew attention to the occurrence of eight dark pigment spots in Atolla which he thought might be excretory organs.

It is shown that these spots are a specific character occurring only in some specimens, and medusae with this character have been named Atolla vanhöffeni n.sp. This species can now be distinguished from A. wyvillei by other characters.

The parasitic copepod, Splanchnotrophus willemi, is recorded infecting the nudibranch Ancula gibbosa for the first time in the UK. Seven out of twenty Ancula gibbosa sampled from Mumbles, Swansea, UK, were found to be infected with S. willemi. Light microscopy was used to investigate the effects of S. willemi on its host. In six hosts the internal damage caused was minimal. However, in one host the damage was extensive resulting in the disintegration of the digestive and reproductive viscera. One other A. gibbosa not parasitized, exhibited similar damage and it was postulated that this animal may have survived infection. In all cases of infection there was never more than one male or one female S. willemi present.

1. A special study has been made of a small Metridiuni-like anemone found at Dingle, Liverpool, in comparison with the typical form of Metridium senile (L.) var. dianthus (Ellis).

2. Penicilli, formerly believed to be absent from the acontia of typical M. senile, have been discovered in abundance in the young, but rarely in the adults. In young and sexually mature specimens of the Dingle anemone they are also abundant.

3. There is close agreement between the anatomy of the Dingle form and the typical M. senile.

4. A considerable amount of variation occurs in the Dingle anemone, as in M. senile var. dianthus and M. marginatum, Mime-Edwards.

5. The resemblances and differences between the Dingle form and M. senile indicate that the former is a dwarf variety of the latter.

6. The discovery of an abundance of penicilli in the acontia of young typical M. senile and mature specimens of the Dingle variety, in conjunction with the great amount of variation in the genus Metridium, suggests that a reconsideration of the systematic position of the genus is necessary and would justify either the restriction of the family Metridiidæ to the single genus Metridium, or else the fusion of the Metridiidæ with the Sagartiidæ. The sum of the evidence appears to lie in favour of placing the genus in a family by itself.

In a study of the breeding biology of Euchaeta norvegica (Boeck), Hopkins & Machin (1977) analysed the placement and frequency distribution of spermatophores on females. They found the number of spermatophores on sampled females to be underdispersed relative to the Poisson distribution and concluded that ‘virgin’ females are more attractive to males than females with spermatophores attached. They fitted the Greenwood & Yule (1920) model but drew no conclusions.

The type of question which may be studied by fitting such a model is whether the attraction of males to ‘non-virgins’ is independent of the time since the first spermatophore was attached and also independent of the number of spermatophores already attached. This problem has been further investigated by fitting a version of the Greenwood & Yule model based on asynchronous recruitment of mature females. This version of the model is fully described in Schweder (1979); in this paper the results and biological implications are discussed.

During the expedition POS397 ‘GroMet’ in 2010 the sediments of the Great Meteor Seamount (GMS) plateau were sampled quantitatively for the first time, allowing statistical analysis of the community structure of Harpacticoida and Canuelloida. Analysis of similarity revealed no differences between three geographic regions at family/species level. Analysis of diversity indicated slightly greater diversity in the south, with more species belonging to more genera/families. Dispersal opportunities possibly occurring at the plateau (emergence, erosion, rafting) are discussed. Of 18 investigated families 106 species were identified, but only 5.66% were already scientifically known and widely distributed. Within the investigated families, 37.74% of the species belonged to shallow-water genera, leading to the conclusion that the plateau was once connected to shallow-water habitats, perhaps functioning as a stepping stone, but is now geographically isolated. This isolation is most likely due to seafloor spreading of the Atlantic Ocean and descending of the GMS. On the plateau, six species with wider distribution ranges were present, indicating that species may arrive accidentally, but their means of settlement remains unknown. Comparisons of the identified GMS plateau fauna with that of other seamounts and mid-oceanic islands revealed similar communities at family level, but at species level the GMS shares only one species with the Seine Seamount; all other elevations had more species in common. Hence, the GMS plateau is considered to be isolated regarding benthic Copepoda but may play an important role in meiofaunal species distribution, as it represents a shallow-water habitat within the deep sea.

Two species of Farranula, including a new species, are described from off Jeju Island, Korea (East China Sea). Farranula orbisa sp. nov. can be distinguished from its congeners F. curta (Farran, 1911) and F. rostrata (Claus, 1863) by a combination of morphological characteristics as follows: in females, (1) eyes located on the frontal part of prosome adhered to each other, (2) second urosomal somite distinctly rounded from the anterior to mid-region in lateral and dorsal view, (3) second urosomal somite ornamented with fine spinules on anteroventral margin; in males, (4) sharply contracted portion of second somite located at two-thirds distance from anterior margin, (5) caudal rami relatively longer compared to width at its base. The new species F. orbisa was erroneously identified as F. rostrata (Claus, 1863) from the East China Sea and as F. curta (Farran, 1911) from the Indian Ocean. The poorly described F. carinata (Giesbrecht, 1891) from the East China Sea is redescribed here based on both sexes of specimens and compared to its morphological variability with specimens from other regions.

The present study demonstrated histochemically that the enzyme activity was present in the cerebral vesicle, epidermis, muscles, endostyle and anus of amphioxus Branchiostoma belcheri tsingtaunese. This is the first noted report on localization of constitutive nitric oxide synthases in a celphalochordate.

The monogenean gill parasites from Scyliorhinus canicula and S. stellaris at Plymouth have been found to be identical; their proper taxonomic designation is Hexabothrium appendiculatum (Kuhn, 1829) Nordmann, 1832. H. canicula (Cerfontaine, 1899) Price, 1942 is a synonym of H. appendiculatum.

The hexabothriid collected from Raia clavata at Plymouth has been identified as Rajonchocotyle emarginata (Olsson, 1876) Sproston, 1946, and R. clavata Bracey (in Sproston, 1946) has been shown to be synonymous with it.

The presence of Stoloteuthis leucoptera in the Mediterranean is recorded on the basis of three specimens, including an adult male, caught by IKMT and by commercial otter-trawl in the Ligurian Sea. The hypothesis of a recent immigration is discussed.

The list of Mediterranean cephalopods (Mangold Wirz, 1963; Torchio, 1968; Bello, 1986; Mangold & Boletzsky, 1987) includes the Sepiolidae of the subfamily Heteroteuthinae, whose members are supposed to be pelagic throughout their life cycle. Mangold Wirz (1963) recognizes in the Mediterranean fauna the unique species Heteroteuthis dispar, the other authors include H. atlantis Voss, which Voss himself (1955) reported at Messina. To this group may now be added Stoloteuthis leucoptera (Verrill, 1878) a species until now recorded in limited Atlantic areas. Verrill (1881) wrote “This species is an exceedingly beautiful one, when living, owing to the elegance and brilliancy of its colours and the gracefulness of its movements. In swimming it moves its fins in a manner analogous to the motion of the wings of a butterfly.”

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.

Red vent syndrome (RVS) has previously been reported in returning wild Atlantic salmon, Salmo salar from Canada, Iceland, Ireland, Norway and the UK. Affected fish show reddening and swelling in the perianal/vent area, with scale loss, ulceration and bleeding in severe cases. Studies in the UK and elsewhere report the condition to be induced by Anisakis simplex sensu stricto (s.s.) larvae. This parasite, commonly reported in several marine fish species, is typically found in the body cavity and the skeletal muscle, but has recently been reported within the vent tissues of salmon. This latter finding may reflect greater efforts in examining this body portion due to current awareness of the parasite presence in this atypical location. Based on clinical observations, affected fish are classified into three categories according to the severity of the external lesions, but quantification of the vent parasite numbers in relation to the categories, and assessment of the relative importance of this area as a site of infestation, are missing to date. This investigation aimed to provide data on parasite number and distribution in the viscera, skeletal muscle, peduncle and vent area and to confirm the identity of the larvae found in the vent and the viscera. The study showed the perianal/vent region harbours the highest total number of A. simplex larvae per fish and, proportionally to fish biomass, is the most heavily infested body location irrespective of external severity levels of RVS.

Numbers of naked amoebae (Gymnamoebae) inhabiting the lower intertidal zone of two sandy beaches were estimated using a novel enrichment cultivation method. Samples were collected between June and September, 1999. Beach sand at Kames Bay, Isle of Cumbrae, Scotland contained on average 2604 amoebae cm−3 while at Dania Beach, Florida, USA, sand harboured 4236 amoebae cm−3. This is the first study to focus on the abundance of naked amoebae inhabiting a sandy beach. These numbers are higher than densities generally reported for shallow subtidal sands and show that amoebae must be considered in future studies on the dynamics of sandy beach communities.

A new species of Craniella from the Aleutian Islands is described. Craniella sputnika sp. nov. differ from all other species of Craniella in its habitus, absence of microscleres and size of spicules. The name refers to its resemblance to Earth's first artificial satellite, due to its spherical body with long spines. The new species was observed growing on another demosponge, Myxilla sp. We propose transferring two species currently in Craniella to Tetilla (Craniella ellipsoidea Hoshino, 1982 and Craniella laminaris (George & Wilson, 1919)) and two subspecies (Craniella globosa anamonaena Tanita, 1968 and Craniella laminaris symmetrica (Wilson, 1931)) from Craniella to Tetilla. As Craniella globosa anamonaena Tanita, 1968, is actually a species of Tetilla we suggest raising the subspecies to species rank as Tetilla anamonaena. Conversely we think that two species, Tetilla ovata (Thiele, 1898) and Tetilla hamatum Koltun, 1966 should be transferred to Craniella.

Soleid eggs caught in the plankton off Algiers were reared and identified. Thus, the egg and the yolk sac stages of Microchirus ocellatus (L.) and M. azevia (Capello) were described, compared and differentiated from the corresponding stages of M. variegatus (Donovan). For the latter species, a large perivitelline space was often discernible.

In 1889, Cunningham referred some pelagic eggs caught near Eddystone (English Channel) to Solea variegata, owing to their similarity to the mature ovarian eggs of this species. Moreover, he considered the embryonic and larval stages described, illustrated and named ’species no. 1'by Raffaele (1888) as belonging to the same soleid. In further works, Cunningham studied the two-day-old larva (1890) and the newly hatched larva (1896). These papers and some others relating to Microchirus variegatus (Donovan, 1808) (present name of S. variegata) were reviewed by Ehrenbaum (1905), Padoa (1956), Nichols (1976) and Russell (1976).

Such eggs are often collected in the plankton of the Bay of Algiers, but I noted a great variability in their features. According to Quero et al.