A comparative analysis of nematocysts in Pelagia noctiluca and Rhizostoma pulmo from the North Adriatic Sea

Nematocysts of the scyphozoans Pelagia noctiluca and Rhizostoma pulmo were examined. In R. pulmo 4 types of nematocyst were observed: heterotrichous microbasic euryteles; holotrichous isorhizas; atrichous a-isorhizas; and atrichous -isorhizas. In P. noctiluca 5 types of nematocyst were seen: heterotrichous microbasic euryteles; heterotrichous isorhizas (previously described as atrichous isorhizas); holotrichous O-isorhizas; atrichous a-isorhizas; and an undescribed type, which in its structure and discharge mechanism resembles microbasic p-mastigophores. The results show, in both P. noctiluca and R. pulmo, a greater variety of nematocysts than described in previous studies.     

A checklist of parasitic nematodes from marine fishes of China

A checklist of the parasitic nematodes of Chinese marine fishes is presented. This fauna comprises 90 species, representing 31 genera, 13 families, nine superfamilies, three orders and two subclasses. Additional details for each species include the hosts, localities and references which represent the source of these data.     

Synthesis of complex-type glycans derived from parasitic helminths

Chemical synthesis of complex-type glycans 1 and 2 derived from eggs of parasitic helminths, Schistosoma mansoni and Schistosoma japonicum, is described. These branched sugar chains were synthesized regio- and stereoselectively by using beta-mannosylation, desilylation under high pressure, and glycosylation in frozen solvent as key transformations.     

Synthesis of complex-type glycans derived from parasitic helminths

Chemical syntheses of complex-type glycans derived from the eggs of parasitic helminths, Schistosoma mansoni and Schistosoma japonicum were achieved. In addition, their analogs, which lack xylose and/or fucose residue(s), are described. These branched sugar chains were synthesized regio- and stereoselectively by using beta-mannosylation, desilylation under high-pressure and glycosylation in frozen solvent as key transformations.     

An annotated checklist of North Sea cartilaginous fish species

A checklist is compiled of all cartilaginous fishes (sharks, skates, rays and rat-fishes) which were so far recorded from the North Sea, along with their English common names. The objective of the study was to provide background information in light of the rapidly changing species diversity with overfishing and climate change as the main cause of changes in their status, thereby providing a reference tool for comparative purposes. This was also undertaken because usually the literature provides general information on the biology and covers the entire geographic range of a species but is not concerned with the status in a particular area. Presently the list contains 57 species, including 37 sharks, 19 species of skates and rays and 1 rat-fish species (also frequently called rabbit-fish or chimaera). Annotations were made for a number of selected species, as to their historical distribution and the present status.     

Bioerosion features of boring polydorid polychaetes in the North Adriatic Sea

Hydrobiologia - Considering the pivotal role played by erosive organisms in the marine habitat and the scanty knowledge of this phenomenon in the Mediterranean Sea, the present study aimed to...     

A revised checklist of planktonic diatoms and dinoflagellates from Helgoland (North Sea,German Bight)

A checklist based on net samples taken twice weekly from 2001 until May 2003 is presented. Identification is based on observations under direct light microscopy and after taking some organisms in culture. The checklist includes 227 taxa observed at the Helgoland Reede sampling station. One hundred and thirty-two species of diatoms from 53 genera and 95 species of dinoflagellates from 35 genera have been recorded from net samples and cultures. Thirty-five diatom and 28 dinoflagellate taxa were documented in the Helgoland phytoplankton for the first time. The list does not claim to be complete, but provides an updated list of the taxa found at Helgoland and, for convenience, also includes data published for different adjacent areas.Communicated by K. Wiltshire     

Serine protease inhibitors of parasitic helminths

Serine protease inhibitors (serpins) are a superfamily of structurally conserved proteins that inhibit serine proteases and play key physiological roles in numerous biological systems such as blood coagulation, complement activation and inflammation. A number of serpins have now been identified in parasitic helminths with putative involvement in immune regulation and in parasite survival through interference with the host immune response. This review describes the serpins and smapins (small serine protease inhibitors) that have been identified in Ascaris spp., Brugia malayi, Ancylostoma caninum Onchocerca volvulus, Haemonchus contortus, Trichinella spiralis, Trichostrongylus vitrinus, Anisakis simplex, Trichuris suis, Schistosoma spp., Clonorchis sinensis, Paragonimus westermani and Echinococcus spp. and discusses their possible biological functions, including roles in host-parasite interplay and their evolutionary relationships.     

Distribution of zinc in parasitic helminths

The distribution of zinc in representative groups of parasitic helminths was determined by the use of the atomic absorption spectrophotometer. The results of these analyses have shown that growing flukes (smaller forms) with active oogenesis and spermatogenesis contained more zinc than old (large) or very old adults with an empty uterus and large lobulated testes. In cestodes, the neck region and immature proglottids showed more zinc concentration than mature and gravid proglottids and fully grown cyst walls. Similarly, the youngest endogenous daughter cysts of Echinococcus granulosus contained more zinc in their walls than those of larger/older forms. Zinc was concentrated more in nematode eggs than in adult females.     

A mycological survey of the South Adriatic Sea

A total of 498 fungal isolates belonging to 33 genera and 90 species were identified in the course of a 2-yr survey of the southern part of the territoreal waters of the Yugoslav Adriatic Sea. The best represented genus was Penicillium (32.12% of the total number of isolates), the P. chrysogenumnotatum series being the most abundant, followed by P. verrucosum var. cyclopium, and P. brevicompactum The genus Aspergillus represented 22.28% of the total. A. versicolor being the most ubiquitous. The Dematiaceae as a group, with 148 isolates included in 14 genera and 26 species, accounted for 29.71% of the total; the dominant genera were Cladosporium, Alternaria, and Ulcladium, with 14 25, 5.42 and 4.21%, respectively of the total number of isolates. Hyphomycetes with hyaloconidia, with 46 isolates included in 9 genera and 20 species, constituted about 8.83%, the best represented genus in this group being Fusarium, with 10 identified species. The Sphaeropsidales accounted for 5.42% of the total number of isolates, the genus Phoma being the most abundant.The number of isolates obtained from surface waters accounted for 85% of the total. The decreasing number of isolates in the water column was particularly evident in the case of the most ubiquitous species, a fact which may be explained by the influence of the contact of water masses with the atmosphere and the lower salinity of the surface waters. The distance from the shore as well as the human factor is reflected in the number of isolates and species. The ecological factors influenced not only the fungal population densities, but also their quality.     

Pyridine nucleotide transhydrogenases of parasitic helminths.

Mitochondria from the parasitic helminth, Hymenolepis diminuta, catalyzed both NADPH:NAD⁺ and NADH:NADP⁺ transhydrogenase reactions which were demonstrable employing the appropriate acetylpyridine nucleotide derivative as the hydride ion acceptor. Thionicotinamide NAD⁺ would not serve as the oxidant in the former reaction. Under the assay conditions employed, neither reaction was energy linked, and the NADPH:NAD⁺ system was approximately five times more active than the NADH:NADP⁺ system. The NADH:NADP⁺ reaction was inhibited by phosphate and imidazole buffers, EDTA, and adenyl nucleotides, while the NADPH:NAD⁺ reaction was inhibited only slightly by imidazole and unaffected by EDTA and adenyl nucleotides. Enzyme coupling techniques revealed that both transhydrogenase systems functioned when the appropriate physiological pyridine nucleotide was the hydride ion acceptor. An NADH:NAD⁺ transhydrogenase system, which was unaffected by EDTA, or adenyl nucleotides, also was demonstrable in the mitochondria of H. diminuta. Saturation kinetics indicated that the NADH:NAD⁺ reaction was the product of an independent enzyme system. Mitochondria derived from another parasitic helminth, Ascaris lumbricoides, catalyzed only a single transhydrogenase reaction, i.e., the NADH:NAD⁺ activity. Transhydrogenase systems from both parasites were essentially membrane bound and localized on the inner mitochondrial membrane. Physiologically, the NADPH:NAD⁺ transhydrogenase of H. diminuta may serve to couple the intramitochondrial metabolism of malate (via an NADP linked “malic” enzyme) to the anaerobic NADH-dependent ATP-generating fumarate reductase system. In A. lumbricoides, where the intramitochondrial metabolism of malate depends on an NAD-linked “malic” enzyme which is localized primarily in the intermembrane space, the NADH:NAD⁺ transhydrogenase activity may serve physiologically in the translocation of hydride ions across the inner membrane to the anaerobic energy-generating fumarate reductase system.     

A new species of haploporid (Digenea) from the South China Sea

Megasolena dongzhaiensis n. sp. was collected from the intestine of Scatophagus argus (Linnaeus) (Perciformes: Scatophagidae) from the Dongzhai Bay (110 degrees 32'-37'E, 19 degrees 51'-20 degrees 1'N), Hainan Province, China. It resembles Megasolena acanthuri Machida and Uchida, 1991 in having larger body size, but it differs from the latter species in having an oral sucker that is larger, instead of smaller, than the acetabulum (sucker length ratio 1:0.456-0.494, and width ratio 1:0.61-0.65 in M. dongzhaiensis n. sp., as opposed to 1:1.3-1.7 in M. acanthuri). Moreover, the cuticle is spinose rather than aspinose; there is a band of circular muscle in the pharynx, and its eggs are smaller instead of larger (0.062-0.068 x 0.036-0.039 in M. dongzhaiensis n. sp., compared with 0.087-0.103 x 0.058-0.072 in M. acanthuri). Finally, the intestinal bifurcation is anterior, instead of dorsal, to the acetabulum. It resembles other species of Megasolena Linton, 1910 in having oral sucker larger than the acetabulum, and in having a circular muscle band in the oral sucker and pharynx, but it differs in having a larger body and smaller eggs. This is the first record of a Megasolena species from ray-finned fishes as well as in China.     

A description of rodlet cells from the alimentary canal of Anguilla anguilla and their relationship with parasitic helminths

Rodlet cells in intestinal epithelia of infected and uninfected European eels Anguilla anguilla from brackish and fresh water were studied by light and electron microscopy. Deropristis inflata (Trematoda) was found in eels from brackish water, whereas eels from fresh water were infected with Acanthocephalus clavula (Acanthocephala). In a comparison between uninfected and infected eels from brackish water, a higher number of rodlet cells was recorded in the intestinal epithelia of infected fish. Evidence is presented that rodlet cells secrete their contents in a holocrine manner into the lumen of the eel intestine. The occurrence of organelles within the mature rodlet cell was rare. ? 1998 The Fisheries Society of the British Isles