The wide-eyed flounder Bothus podas podas is a small fish that belongs to the Bothidae family. This species is a demersal fish inhabiting sandy and muddy bottoms where it lives buried in the sand. In the Gulf of Gabès (Tunisia), B. podas podas is an uncommon fish caught in small quantities by trawlers, between depths of 20 and 50 m. There are very few complete studies of the biology of this fish in the Mediterranean Sea. Even in Tunisia, the biology of B. podas podas is unknown. In addition, it has been noticed that during the last few years, despite having weak commercial value, this fish has attracted the fishermen's attention of the region after the observed reduction in the flat fish stocks, particularly the Egyptian sole Solea aegyptiaca. The aim of this work was to study the reproduction of B. podas podas and determine the sex-ratio, the sexual cycle, the spawning period and the first sexual maturity. The data for this work was collected during the period of May 2004 until September 2005. In general, this study shows that the proportion of sexes is in favour of females and permits us to analyse the sex-ratio variations according to the size and age of the fish. It also seems that males grow faster than females. The monthly following of the gonad somatic index (GSI), the liver somatic index (LSI) and the condition factor (K) enabled us to determine that the period of maturation occurs from May to August, to define the spawning period from August to November and to deduce that B. podas podas uses the lipid reserves accumulated in the liver to develop its gonads. Concerning the first sexual maturity it was noted that the main size related to 25%, 50% and 75% of matured individuals were respectively for males: 19.68 cm, 21 cm and 22.34 cm and for females: 18.87 cm, 20.4 cm and 21.93 cm. The coefficients of the logistic function were for males: a = 0.827, b = 17.38 and for females: a = 0.718, b = 14.65.

Vertical extinction coefficients can be determined in water using selenium rectifier cells and colour filters. The cells are connected positive to negative with a simple 0-50 microammeter across the circuit, as in the Campbell-Freeth method. There is no deflexion when the two points of contact are brought to the same potential. This is done by lowering one cell into the sea to balance the rather less sensitive deck cell. The light reaching the latter is then reduced by the successive addition of opalized plates, to approximately 60, 30, 20 and 10 %, and the sea cell is lowered further to balance at each stage. The extinctions can then be calculated by the usual formula from the known percentage transmissions and the observed depths of balance. For each plate or combination a factor may thus be obtained which when divided by the appropriate depth gives the extinction. The method is rapid in operation and the drift error can be rendered negligible. The results agree with those found by the standard potentiometer method, but the applications of the new method are necessarily more limited.

Through rearing known age individuals and maintaining chemically marked adults in captivity, this study explored the rate of increment formation in southern calamary (Sepioteuthis australis) statoliths over seasonal (summer and winter) and ontogenetic (hatchlings and adults) extremes. A ‘one increment–one day’ relationship was verified for captive-reared hatchlings up to 40 days post-hatching which remained stable across the seasonal extremes. This relationship, however, was not evident in the chemically marked adults as inconsistencies of up to 44 days were detected between the number of days elapsed post-stain and the increment count. No seasonal effect was detected in the ratio between increment count and days elapsed, however, the degree of underestimation was consistently greater for winter-caught adults by approximately 2.5 increments relative to summer-caught adults. This less-than-daily increment formation in adults may be due to: (1) the periodicity of increment formation changing throughout the squid's lifespan; (2) deleterious effects associated with rearing squid in captivity; and/or (3) compromised interpretation of the statolith microstructure as a result of the preparation method.

A troublesome problem arises in connexion with the tracing of Trematode life histories; namely how to obtain the intermediate and final hosts free from Helminth infections. It was discovered—fortunately early— during the study of the parasites of Peringia ulvœ Pennant 1777, that all the species of certain groups of cercariæ, and also related species from other molluscan hosts, encyst most readily in the same species of fish or crab. It is therefore not surprising if the mature trematodes are also to be found in the same host. It is obvious that the greatest confusion can arise from these facts. To add to the difficulty it is often impossible to distinguish between the worms within the cyst, and therefore the dissecting out of cysts for feeding purposes is impracticable.

By far the most satisfactory results are obtained by rearing the hosts in the Laboratory, but unfortunately with marine organisms this is often impossible.

The Black-headed Gull was selected as the final host in a series of experiments, approximately 40 Helminth parasites having been recovered from this bird in Europe. Attempts were made to rear the bird in captivity.

Two dozen eggs were first placed under various hens, but all those were lost owing to the great fragility of the shells. The birds invariably smashed the eggs in turning them. An incubator was then tried but a large series of failures also occurred before the discovery of the correct temperature. Subsequently half the birds died on account of wrong treatment after hatching.

A new Brazilian endemic Monanchora is described, M. brasiliensis sp. nov. It is clearly distinct from any other species in the genus by the monodentate shape of its anchorate isochelae, and its smooth, centrotylote and strongyloid microrhabds. Monodentate anchorate isochelae are relatively common, normally abundant, and represent the main diagnostic character for recognizing the new species, but microrhabds are usually rare and may be even absent. Monanchora brasiliensis sp. nov. can be further differentiated from other Atlantic species of the genus in eventually showing tetralobate branches and a skeleton formed by well-defined honey-coloured spongin fibres. The affinities of the new species with other crambeids and the nature of anchorate isochelae, microrhabds as well as the megascleres in defining Monanchora are discussed. An amended diagnosis for the genus is proposed.

In two previous papers on the distribution of some nutrients and phytoplankters in the Tamar estuary, anomalies in the vertical profile of phosphate concentration have been demonstrated (Mommaerts, 1969a, b). In the top three metres the water column was stratified so that a dip of no more than 50 cm revealed a PO43- (calculated as phosphorus) variation that would normally be accompanied by a marked change in salinity. On the other hand, salinity determinations revealed no dilution at all. Such unexpected variations occurred two or three times in the layer studied. There was an excellent correlation between the PO43- and NO3- (calculated as nitrogen) concentrations on the one hand and between the silicate concentration and salinity on the other hand. Such a phenomenon could indicate either pollution or biological activity distributed along specific layers. The idea of pollution seemed to be most likely but, to fit the observations, the pollutant would have to match the salinity of the estuary at the precise spot where it enters.

The urohyal is incorporated within the hyoid and branchial arches and performs a significant role in the mouth opening-closing mechanism of fishes, and is considered a synapomorphy of teleostean fishes. Morphological variation of the urohyal, in terms of size and shape parameters, can allow species identification. Morphology of the urohyal in 49 species belonging to 43 genera and 29 families from the Persian Gulf and from the Oman Sea were compared using size and shape measurements. The results examine the suitability of using the urohyal morphology in differentiating fish species from this region; highlighting the taxonomic value of the urohyal, which until now, had been studied little in terms of use as a diagnostic feature in the classification of teleosts.

The process of asexual reproduction, described below, is, as far as the writer is aware, unique among hydroids. In all known species of hydroids in which an asexual bud formation has been described (e.g. in Hydra), the mouth and oral tentacles develop at the free end of the bud and the proximal or fixed end becomes the base. The sequence of development of medusa buds is essentially similar. This method applies also to budding in other Coelenterates. In the present instance the bud instead of growing out “head first,” came off “tail first,” came off “tail first” –the proximal end developing mouth and oral tentacles and the free end becoming the stalk. I can find no recoid of such a method having been described before.

A new species, Oikopleura villafrancae, from the family Oikopleuridae (Lohmann 1915), subfamily Oikopleurinae (Lohmann 1896), genus Oikopleura (Mertens 1830), is described from numerous specimens collected at mesopelagic depth (360–880 m) during two different cruises: Migragel II (May 1988) and Medapp (May 1990) in the Ligurian Sea (northwest Mediterranean) between Villefranche-sur-Mer (French Riviera) and Corsica, respectively by the ‘Cyana’ and ‘Johnson-Sea-Link’ manned submersibles.

Big-bellied seahorses, Hippocampus abdominalis (Chordata: Syngnathidae), feed predominantly on swarming mysids in southern Tasmania. We tested the possibility that kairomones mediate this predator/prey interaction. ‘Fish water’ was prepared by holding one seahorse in 4 l of seawater for 1 h and using this water within 1 h to test for presence of kairomones. One ml of this water pipetted into a tank containing five mysids, Paramesopodopsis rufa (Arthropoda: Mysidacea), induced a significantly increased number of tailflips (mysid escape response) compared with control seawater. The same effect was seen whether seahorses were fed or starved immediately before the experiment. This effect was not seen when realistic concentrations of excretory products, either ammonium hydroxide or urea, were used instead of fish water. When seahorses were kept in visual contact with mysid prey, but unable to capture them, subsequent testing of the ‘fish water’ in the same way as above did not produce a significant increase of tailflipping in mysids. Thus it appears that, when attacking, seahorses can suppress release of kairomones in order to remain chemically inconspicuous to their prey. This is the first demonstration of this phenomenon. When mysids in a cohesive swarm (65 or 100 individuals) were exposed to ‘fish water’, no significant anti-predator response i.e. decrease in swarm volume, could be detected. We interpret these results to indicate the greater vulnerability of mysids when not in social groupings (swarm or school) and the higher likelihood of an energetic response (particularly tailflipping) to a threat.

The English fisheries which were investigated with the Plankton Indicator in 1931,1932, and 1933 were divided into three areas, i.e., those off Shields, the Humber mouth and the East Anglian coast (this last fishery was also sampled in 1930). All the samples in the Shields area lie between 56° 00 N. Lat. and 54° 20 N. Lat., whilst the majority (80%) lie in the area between 54° 45 N. Lat., and 55° 30 N. Lat. and a line parallel to and some 40 miles from the coast. This is an area of some 1600 square miles. In the Southern Bight Lat. 53° 00 N. was taken as a division between the Humber and the East Anglian areas. The distribution of all the samples is shown in Figs. 1 to 4. With the exception of the samples obtained by the Ministry of Fisheries research ship Onaway in June, 1931, and four samples obtained by H.M.S. Chenoell in September, 1933, all those in the Shields area have been collected by individual drifters engaged in the fishery. The Humber and East Anglian samples were obtained from both drifters and gunboats of the Fishery Protection and Mine Sweeping Flotilla alongside drifters fishing. The manner of collecting these samples has been described in Part I (p. 153).

Crab-baited traps, with a 5-mm diameter opening, were deployed 90 mm off the seabed monthly at Lobster Bay, Hong Kong, for one year between 1998 and 1999. Visitors drawn to the traps were mainly species of Ceradocus (Gammaridea: Melitidae), Tisbe (Harpacticoida: Tisbidae) and Nebalia (Leptostraca: Nebaliacea). Apart from Ceradocus sp., all were scavengers with catches using baited traps significantly exceeding unbaited controls. Ceradocus sp. was apparently drawn to traps for refuge. The trapped scavenger community composition changed with deployment duration in the presence of bait. Nebalia sp., Neanthes cricognatha (Polychaeta: Nereidae) and Lepedepecreum sp. (Gammaridea: Lysianassoidea) were identified mostly two/three-days post-deployment, exhibiting a potential preference for rotten organic matter. Seasonal catches were also identified for all three visitors with maxima between October 1998 and April 1999. Such seasonal patterns might be related to either turbulence destabilizing the substratum during this period or life cycle patterns in the study area.

The present study is the first record of twinning in Lagenorhynchus acutus and indeed any Lagenorhynchus sp. Both foetuses were male and located in the left uterine horn, had distinct grossly normal placentas and amniotic sacs, and were therefore likely dizygotic twins. The twins were an incidental finding in an animal that died of a systemic Brucella ceti infection.

This paper discusses a number of biological aspects, concerning a new sea anemone species (Paranemonia vouliagmeniensis Doumenc et al., 1987 ) (Actiniaria: Anthozoa), discovered in Lake Vouliagmeni, near Athens, Greece. The specialized environment of the lake, with elevated and stable temperatures throughout the year, brackish waters and large mineral content presents a very specialized biotope in which Paranemonia wuliagmeniensis is an important member. Certain aspects of its life cycle were investigated, especially population structure, feeding habits and life history. The population was found to be made up of two sub-populations; one established on algae in deeper parts of the lake, and an older one living on gravel in shallower habitats. Feeding preferences depended on the anemone's ability to catch prey, combined with the composition of the prey. The anemone was also found to be viviparous and demonstrated r-characteristics in its life history (short lifespan and large number of embryos).

The morphology and infraciliature of a new marine ciliate, Tachysoma multinucleata sp. nov., collected from the Jawol Island near Incheon, Korea, were investigated using live observation and protargol impregnation. The new species is characterized by: size in vivo about 65×25 μm, body oval to ellipsoid. Three frontal, one buccal, four frontoventral, three ventral and two pretransverse cirri. Fifteen to 22 left and 13–21 right marginal cirri and about 21–27 adoral membranelles. Cortical granules fine and yellowish, arranged around cirri and dorsal cilia. Usually 12–26 macronuclear nodules. Three dorsal kineties. Marine habitat.

Patterns of cell elongation and differentiation were examined in a number of Audouinella spp. In all species examined, cells reached their maximum length within a few cells of the apex after which the length (and diameter) of cells became stable. No size differentiation of cells associated with lateral branches was observed, although the basal cells of lateral branches were usually smaller than those in the main axis (except in A. purpurea (Lightf.) Woelkerling and A. parvula (Kylin) Dixon). The position of the lateral branches on branch bearing cells showed little variation and could be used to develop quantitative characteristics for species delimitation. Early stages of development in A. secundata (Lyngbye) Dixon showed an increase in size of apical and subapical cells with plant height, with cell length decreasing toward the base. These developmental features confirm the simple morphology of Audouinella spp, and show that models of growth and differentiation proposed for the Ceramiaceae generally do not apply to the Acrochaetiaceae.

The morphology of the spines of the ophiuroid Ophiocomina nigra is described, with particular reference to the nervous system and the sensory and secretory structures of the epidermis. The nervous system is composed of two main spinal nerves, located at the centre of the spine, and their associated branches. There are three secretory cell-types described: (1) fibrillar secretory cells which produce long, javelin-shaped secretory pack-ages and, occurring exclusively in the basal two thirds of the spine, penetrate deeply with their basal regions lying close to the axial nerve running through the spine centre; (2) granular secretory cells, which also penetrate deep within the spine, contain secretory granules in the form of spherical dense vesicles (~1.3 μm in diameter); and (3) goblet secretory cells, filled with packages of loose amorphous material, are superficial in location and usually found associated with a type A ciliated sensory cell. The secretions of the fibrillar and granular secretory cells are thought to perform the functions of defence and feeding respectively. A number of different ciliated sensory cell-types have been identified. Apart from the situation with the goblet cells, no close association was found between secretory and sensory cells. It is suggested that the nervous, sensory and secretory cells act together to form a mucous secretion system with centralized, rather than local control. This system appears to operate when it is advantageous to produce secretion all over the body simultaneously once any portion is stimulated. Stimulation of sensory cells might result in axonal excitation of the spinal nerves and hence to the entire epineural nervous system.

One shark was landed at the Naval Base Pasha Liman, Bay of Vlore, Albania, the Adriatic Sea. Photographic records only enabled the specimen to be placed in family Odontaspididae or Carchariidae. Later examination of the preserved head, dry jaw and dentition identified the specimen as Odontaspis ferox. This is a rare record and the northernmost Mediterranean observation of this species, and the first Adriatic record for several decades.

In November, 1933, a few medusæ were found in the plankton off Plymouth belonging to the genus Eucheilota. The only species of this genus so far recorded from northern European waters is Eucheilota maculata Hartlaub. The medusæ differed in several respects from this species, one constant difference being that the marginal vesicles never contained more than one concretion. In this respect they resembled E. duodecimalis A. Agassiz, but differed in having a much greater number of tentacles and marginal vesicles.

In October, 1934, the medusæ appeared again in considerable numbers and it was now possible to establish the constant features of the species which has apparently never been described before, except possibly for a drawing given by Hartlaub without a description (see below).

A new species of Trischizostoma collected at depths of 1392–1420 m from western Mexico is described. It represents the first record of the genus in the NE Pacific. The new species is morphologically similar to T. circulare, T. tohokuense and T. richeri. These species all share a large rostrum, expanded eyes and an entire telson. Distinctive characters of the new species include a dorsally unnotched urosomite 1, a subconical coxa 2, a subtriangular propodus of gnathopod 1, a single seta and one protuberance on the palm of gnathopod 2, the presence of 10 spine-teeth in the outer plate of maxilla 1 and of a large, 1-articulate maxilla 1 palp, and the telson with 2 minute simple setae and 2 minute projections distally.