Sclerotization of the perisarc of the calyptoblastic hydroid, Laomedea Flexuosa 1. The identification and localization of dopamine in the hydroid

With histochemical methods, the perisarc and a certain cell type in Laomedea flexuosa have been shown to contain a catecholamine. The only catecholamine detected in methanolic extracts of the hydroid is dopamine. It is thought to be transferred from spherical inclusions in these cells to the perisarc and to be involved in sclerotization. The dopamine-containing cells appear to differentiate in specific regions of the colony and migrate out to all other regions by active amoeboid movement between ectodermal epithelial cells. The rivets (or desmocytes) contain an unidentified phenolic substance and may also be sclerotized structures.     

Redescription ofaulopus bajacali parin & kotlyar, 1984, comments on its relationships and new distribution records

Aulopus bajacali, described from the eastern Pacific Ocean from a single specimen, is redescribed. It is now known from over 400 specimens. It is the only Pacific species ofAulopus belonging with the Atlantic species group ofA. nanae, A. filamentosus, andA. cadenati. It shares a short dorsal-fin base and some color pattern characters with this group. New distribution records from Ecuador and the Galapagos Islands extend its range; it is now known from mid-Baja California (25°N) to about 3°S in the eastern central Pacific.     

Fluoride in tissues of Krill Euphausia superba Dana and Meganyctiphanes norvegica M. Sars in relation to the moult cycle

Summary The fluoride content of whole animals and different tissues of the euphausiid species Euphausia superba and Meganyctiphanes norvegica was analyzed by two different and improved methods of isolation and determination. In contrast to other authors our findings show that the internal organs (muscle, hepatopancreas and hemolymph) contain less than 6 ppm d.w. fluoride this being the same order of magnitude as for vertebrates. The high concentrations reported by other authors must be mainly due to contamination of the soft tissue during storage (post-mortem migration of fluoride from shell) and/or contamination caused by minute fractions of cuticle during dissection. Over 99% of the total fluoride content is located in the cuticle (i.e. integument) of the euphausiids (2600 ppm/d.w. in E. superba and 3300 ppm/d.w. in M. norvegica in pleon cuticle). Analysis of F^- levels in relation to the moulting cycle showed that the uptake in both euphausiids occurs at a comparable and fast rate during the same physiological phase shortly after moult, parallel to the general construction of the cuticle. The internal organs show homeostasis in respect to fluoride. Accordingly, no internal deposition takes place, and F^- is reaccumulated from the external medium at each moult.This work was supported by grants from the DFG No. Ad 24/9 and Bu 548/1     

Redescription of Alona iheringi Sars, 1901 (Chydoridae,Anomopoda, Branchiopoda), a South American species related to A. rustica Scott, 1895

Investigation of Sars' type material reveals that South American Alona iheringi Sars, 1901 (Chydoridae, Anomopoda, Branchiopoda) is a good species, not a synonym of A. rustica Scott, 1895 as was presumed before. A. iheringi is redescribed from the type material. It shows characteristic features of the costata-group, such as transverse lateral head pores and a peculiar shape of the male postabdomen. It is closely related to A. rustica, but differs from it by the morphology of the main head pores, of the III–V trunk limbs, and of the valves.     

Behavioural differences in relation to pycnoclines during vertical migration of the euphausiids Meganyctiphanes norvegica (M. Sars) and Thysanoessa raschii (M. Sars)

An observation on differences in the vertical migration patternbetween Meganyctiphanes norvegica (M. Sars) and Thysanoessaraschii (M. Sars) caused by the presence of a thermocline isreported. Generally, M.norvegica did not migrate through a thermoclineat 50–60 m depth while T.raschii did. This observationis discussed in the context of how the combination of differencesin vertical migration and advection over sill depth may affectthe abundance of fjord stocks of these two euphausiid species.     

A new species of Sabellacheres M. Sars, 1862 (Copepoda: Gastrodelphyidae) from a deep-water benthic polychaete in Antarctic waters, with a key to the species of the genus

Specimens of a deep-living sabellid polychaete of the genus Perkinsiana Knight-Jones dredged in Antarctic waters were found to be parasitised by an undescribed species of the cyclopoid copepod genus Sabellacheres M. Sars, 1862. Specimens of both sexes were studied using light microscopy and SEM, and compared with its congeners. The new species, Sabellacheres antarcticus n. sp., can be distinguished from its congeners by the shape and proportions of the body and brood-pouch, its 4-segmented antennae, the shape and length of the distal process of the second antennular segment, the position of leg 3, and the structure of the male maxilliped. This is only the second record of a species of this genus from the southern hemisphere. The new species was found on a single host species, as is typical for most species of Sabellacheres. A key for the identification of both sexes of the species of Sabellacheres is included.     

Herbivorous nutrition of Cyclops vicinus: the effect of a pure algal diet on feeding, development, reproduction and life cycle

Nutritional requirements, functional response, development andreproduction of Cyclops vicinus were studied with exclusivelyalgal food. Phytoflagellates were found to be adequate foodresources for both juvenile development and egg production.Ingestion measurements were performed with Chlamydomonas reinhardii.The functional response data give evidence for low feeding efficiency,especially for the naupliar stages. A difference between naupliiand older instars was also found in their quantitative foodneeds. A higher threshold food concentration was observed fornaupliar development (0.4 mg C l^–1) than for copepoditedevelopment (0.2 mg C l^–1). The calculation of assimilationefficiencies suggests that the high food requirements are dueto low specific ingestion rates rather than poor assimilationefficiency. Development time decreased as algal density increasedand males developed more quickly than females at all food concentrations.Body size and carbon content increased with increasing foodconcentration. Continuous egg production was observed abovea food concentration of 0.5 mg C l^–1. The results haveimplications for the life cycle of C. vicinus. Summer diapauseis interpreted as a strategy to avoid starvation of the juvenilestages. The facultative herbivory of the adults might be anadvantage when competing against other more carnivorous cyclopoidcopepods. ¹Present address: Agricultural University of Wageningen, Departmentof Mathematics, Dreijenlaan 4, NL-6703 HA Wageningen, The Netherlands     

Triso,a new generic name for the serranid fish previously known asTrisotropis dermopterus,with comments on its relationships

The generic nameTriso is proposed for the epinephelin fish recent authors have identified asTrisotropis dermopterus (Temminck et Schlegel).Trisotropis Gill is a junior synonym ofMycteroperca Gill.Triso is distinctive in its short head, broad interorbital, foreshortened neurocranium, anteriorly inclined parasphenoid, high and laterally oriented frontoparietal crests, high dorsal fin-ray counts, and pouch-like esophageal swellings.Altiserranus woorei Whitley from New South Wales is placed in the synonymy ofT. dermopterus. Altiserranus Whitley, type speciesEpinephelus multinotatus (Peters), is synonymized withEpinephelus Bloch.T. dermopterus occurs in the Northern Hemisphere off Japan, Korea, Taiwan, and China, and in the Southern Hemisphere off eastern and western Australia; thus it is antitropical in distribution. Available evidence indicates thatTriso may be most closely related to the New World genusParanthias Guichenot.     

Organic matter economy of Euphorbia adenochlora with special reference to its life cycle

The dry matter economy of Euphorbia adenochlora Morra et Decne was investigated in a moist tall grassland in the Tajimagahara nature reserve, which protects a riverside grassland on the Arakawa river in Saitama Prefecture, central Japan. Euphorbia adenochlora is a typical short clonal species in the flood plain meadows, but is listed as an endangered species. It starts to grow in late February, and grows fast in early April by using one-third to about half of the dry matter of the rhizomes, which are composed of annual segments up to 8–10 years of age. During the period of fastest growth in early April, the bulk density (g dry weight cm^–3) of the rhizomes attained the minimum value. By the end of May, it reached its maximum. When ¹³CO₂ was fed to the shoots by means of photosynthesis, the concentration of ¹³C-containing photosynthates was highest in the new rhizome segment; the older the segment the lower the concentration of ¹³C. Shoot-clipping of E. adenochlora in late April, when bulk density was near the minimum, greatly depressed shoot growth in the following year. At the beginning of June, all of the aerial shoots of E. adenochlora died out with the growth of tall grasses. These results suggest that E. adenochlora has a life cycle as a spring ephemeral.     

Redescription and assignment of Alona globulosa Daday, 1898 to a new genus Notoalona and a description of Notoalona freyi sp. nov.

The species Daday (1898) describes as Alona globulosa has been critically studied, based on many populations from tropical and subtropical regions of the world, over its whole geographical range. A new species and a new subspecies are described. Based on the morphological characters of this species group, which are markedly different from those of the genera previously used for this species, namely Alona, Alonella, and Indialona, a new genus Notoalona is established. N. globulosa (Daday, 1898) is designated as the type species. Morphological differences of Notoalona, Alona, Alonella, and Indialona are discussed. The diagnostic characters of the genus Notoalona include 1) two bean-like thickenings as headpores on the headshield, 2) a row of submarginal setae along the posterior half of the ventral margin of carapace, 3) first trunk limb ODL with one seta and IDL with 3 setae and a small seta-like notch, 4) small branched seta dorsal to posterior lobe of trunk limb-I, 5) entire carapace of the ephippial female modified as an ephippium with a foamy mass surrounding the egg. N. globulosa has a wide distribution in Asia, Africa, and Australia. The Australian material has been designated as the subspecies australiensis. N. freyi sp. nov. is known only from Florida, USA. More detailed studies are necessary to evaluate the taxonomic status of other populations from America including material described as Alonella sculpta, which certainly belongs to the genus Notoalona.     

Redescription of the life cycle of Haemogregarina simondi (Laveran and Mesnil, 1901) in its vertebrate host the marine fish Solea solea (Linnaeus).

The life cycle of Haemogregarina simondi is described in its vertebrate host the marine flatfish Solea solea. An intraleucocytic schizogony is followed by an intraerythrocytic schizogony giving rise to eight gametocytes. A differentiation into micro- and macro-gametocytes was also observed and thus confirms the results of other authors for H. aeglefini, H. bigemina, and H. sachai. It is postulated that most if not all of the haemogregarines of marine fish undergo similar life cycles as the one described here.     

Anatomy ofTrigonognathus kabeyai,with comments on feeding mechanism and phylogenetic relationships (Elasmobranchii,Squalidae)

The skeleton and musculature ofTrigonognathus kabeyai are described in detail. The particular jaw dentition suggests thatTrigonognathus has a clutching-type feeding action. Several characters that might serve this function are discussed from the point of the functional morphology. The phylogenetic relationships ofTrigonognathus are not fully resolved, but it possesses three of the four synapomorphies of the Etmopterinae, i.e., two separate labial cartilages, no supraotic shelf, and prespinal radiais. Furthermore, three equally probable hypotheses ofTrigonognathus relationships, a sister relationship with all etmopterine genera,Etmopterus+Miroscyllium, andAculeola+Centroscyllium, are discussed.     

Redescription of Bedotella armata from Biscay Bay,northern Spain,the type species of Bedotella Stechow, 1913 (Cnidaria,Hydrozoa, Lafoeidae), with comments on its taxonomic position

Hydrobiologia - The circalittoral and bathyal genus Bedotella, comprising a unique known species endemic to the North European Atlantic (Lusitanian Province), Bedotella armata (Pictet, C. &...     

Observations on life cycle and feeding ecology of two recently introduced predatory beetle species at South Georgia,sub-Antarctic

On South Georgia, two recently introduced species of predatory beetle,Oopterus soledadinus andTrechisibus antarcticus (Coleoptera, Carabidae), were studied in the period November 1991–April 1992. The study area comprised the coastal area around Stromness Bay, in particular the surroundings of the abandoned whaling station at Husvik. The study investigated the life cycle of both species and, forT. antarcticus, aspects of feeding. The occurrence of both teneral and gravid beetles was observed for the whole of the summer period.Trechisibus antarcticus appeared to be the more voracious predator of the two; its impact on other populations of soil animals may be large as shown by its effect on the endemic detritivorous beetleHydromedion sparsutum (Perimylopidae).