EOLID NUDIBRANCHIATE MOLLUSCA FROM BARBADOS

17 species of eolid nudibranch are described from Barbados inthe Caribbean sea of which three are new: Cuthona iris, Cuthonabarbadiana and Learchis evelinae. The present status of thefamilies Cuthonidae and Facelinidae is discussed. (Received 8 July 1982;     

A laboratory study of the effect of non-phytoplankton diets on the reproduction of Calanus helgolandicus

The effect of five non-phytoplankton and one phytoplankton dietson reproduction is described for the copepod Calanus helgolandicusand compared to field fecundity estimates. A fecundity increasefollowed ingestion of larvae of the sea urchin Sphaerechinusgranularis (LSU) and the oyster Crassostrea gigas (OYS) by copepodfemales, whereas a decrease followed ingestion of eggs of thecopepods Acartia and Temora spp. (COP), as a function of proteinconcentration in diets. With larvae of the sea urchin Paracentrotuslividus (SSU) and the dinoflagellate Prorocentrum minimum (PM;standard phytoplankton diet), fecundity was identical. Althoughprotein concentrations differed greatly from one food treatmentto the other, mean fecundity values were rather low. For unknownreasons, and despite their very high protein concentrationsin comparison to in situ, none of these diets could improvefemale fecundity or reach maximum egg production rates reportedin C.helgolandicus. Hatching rates were >80%, stable andsimilar with both PM and COP diets. With SSU, LSU and OYS diets,egg viability was lower than in situ and with PM, showing astrong and mild decrease with time with LSU and SSU, respectively.Ingestion of zygotes of the brown alga Fucus spiralis (ZYG)led to the death of females. These results suggest that denseblooms of zygotes of macroalgae and invertebrate embryos andlarvae, occurring in the continental shelf as part of copepoddiets, could have different effects on the demographic responseof C.helgolandicus.     

Allorecognition in the Colonial Marine Hydroid Hydractinia (Cnidaria/Hydrozoa)

The colonial marine hydroid Hydractinia has a sophisticatedallorecognition and effector system. Unlike many unitary organisms(i.e., vertebrates) which lack a current context for allorecognition,there is the potential for strong selection pressure for allorecognitionand response in Hydractinia. Hydractinia colonies use allorecognitionin intraspecific competition for two dimensional space; spaceis an absolute requirement for Hydractinia to successfully completeits life-cycle and thus interactions for space are of centralimportance for Hydractinia. Studies of the mechanisms, molecules,and genes involved in allorecognition in Hydractinia may contributeto our understanding of the evolution of allorecognition inthe metazoa.     

A probable thecate hydroid from the upper cretaceous of southern England preserved by bioimmuration

An inferred thecate hydroid, moulded on the attachment scar of the bivalvePycnodonte vesiculare, is described from the Santonian Chalk of Kent. The living hydroid was evidently overgrown by theP. vesiculare shell and is preserved as a bioimmuration.Eisenackiella thanetensis gen. et sp. nov. is characterized by a hydrorhiza whose stolons bear hydrothecae alternately to the left and right, and a hydrocaulus consisting of several unbranched stems with alternating hydrothecae. The widely spaced stolonal hydrothecae have adnate proximal parts and erect distal parts. Assignment to an extant hydroid family is difficult: whereas the hydrorhiza resembles that of the Family Lafoeidae, the hydrocaulus is reminiscent of the Family Sertulariidae.     

Unusual trophic strategies of Hydractinia angusta (Cnidaria, Hydrozoa) from Terra Nova Bay, Antarctica

Hydractinia angusta Hartlaub, 1904 has been recorded at Terra Nova Bay (Ross Sea, Antarctica) as epizoic on shells of the Antarctic scallop Adamussium colbecki. The species can exploit different trophic resources: first, polyps are able to detach and ingest tube feet and pedicellariae from the sea urchins Sterechinus neumayeri, grazing on the scallop shell, and second, they also eat masses of benthic diatoms settled among the hydrorhiza of the colony. The particular relationship observed between the hydroid and one of the most common Antarctic sea urchins may prevent or reduce the damage to A. colbecki shells, otherwise caused by the grazing of sea urchins on the algal film of the upper valve of the scallops. H. angusta is the first known species of hydroid that exploits prey several times its own size and the second that does not ingest entire prey but portions of them. The use of benthic diatoms as a food resource has previously been documented for the sub-Antarctic marine hydroid Silicularia rosea. Accepted: 20 December 1999     

FEEDING AND GROWTH OF THE AEOLID NUDIBRANCH CUTHONA NANA (ALDER AND HANCOCK, 1842)

Feeding and growth of the aeolid nudibranch Cuthona nana wasdocumented. Cuthona nana feeds specifically on the colonialhydroid Hydractinia echinata. Nudi-branchs were observed onhermit crab shells in Gos-port Harbor at the Isles of Shoals,Maine and on old bridge pilings near Gerrish Island, Maine. Grazing rates of nudibranchs (3–25 mm) were quantifiedover 24 hour periods in the laboratory. Larger nudibranchs consumedmore hydroid tissue feeding mostly on polyps, whereas smallerindividuals consumed less and fed on mat tissue. Grazing intensityin the field at Gosport Harbor was determined by estimatingthe area of grazed patches of hydroid colonies attached to hermitcrab shells. The average patch size was 5.75% of the total colonyarea. Growth rates for nudibranchs were determined in the laboratory.Growth rates were greatest prior to maturation and oviposition.Animals from Gerrish Island and Gosport Harbor decreased insize after oviposition due to senescence. Nudibranchs from GerrishIsland reached a maximum size of 12 mm, compared to 23 mm foranimals at Gosport Harbor. ^*Present address: Division of Science and Mathematics. Universityof Minnesota, Morris. Minnesota 56267, USA     

YOLDIELLA SEGUENZAE, A NEW SPECIES OF NUCULANIDAE (BIVALVIA; NUCULOIDA) FROM THE MEDITERRANEAN SEA

A new species, Yoldiella seguenzae (Bivalvia, Nucu-loida), froma deep sea community off the north east coast of Sardinia (MediterraneanSea), is described. Morphometrical and statistical comparisonwith the very similar Yoldiella philippiana (Nyst, 1845), andgeneral morphological comparison with other Mediterranean andAtlantic species support the distinc-tivness of Y. seguenzaewhich is distributed in deep waters of the Central MediterraneanSea, Alboran Sea and the Atlantic Ocean. (Received 21 October 1993; accepted 1 July 1994)     

A new hydroid from the Upper Cretaceous of Mississippi

A new fossil hydroid is reported as an organic impression on a calcareous gastropod steinkern from the Prairie Bluff Chalk (Maastrichtian), Oktibbeha County, Mississippi. This is the first such hydroid reported from the Upper Cretaceous of the Atlantic Coastal Plain. The fossil organism consists of anastomosing hydrorhizae forming a holdfast, a fascicled hydrocaulus, and elongated, crenulated and ribbed hydrothecae. The fossil is unlike other Mesozoic hydroids that have been reported from Europe and North America; it is described as Mesodendrium oktibbehaensis gen. et sp. nov. and tentiatively referred to an extant family, the Campanulariidae (Calyptoblastina). The complete preservation of the holdfast, hydrocaulus and hydrothecae suggests that this hydroid lived inside gastropod shells. In analogy with Recent symbiotic hydroids inhabiting mollusc shells, the new specimen described here possibly represents the oldest known example of a symbiotic relationship between hydroids and hermit crabs.     

A NEW METHOD FOR RECORDING THE IN SITU PUMPING ACTIVITY OF INFAUNAL BIVALVES

A new method for measuring the pumping activity of infaunalbivalves is described. The method is based on the simultaneousrecording of three temperatures: (1) the temperature of thesea water above the bivalve, (2) the temperature of the sedimentand (3) the internal temperature of the bivalve. When thermicshifts between sediment and sea water are induced by the sunand/or the ground water, comparison of the three temperaturesprovides information on the pumping activity of the bivalve.The method was applied during the day to Tapes decussatus andRuditapes philippinarum (Veneridae). Their pumping activityappears continuous except during emersion at ebb. Sestonic concentrationsas high as 325 mg 1^–1 induced no detectable interruption.Analysis of the data suggests that in situ pumping rate is notconstant but fluctuates. (Received 14 February 1996; accepted 15 May 1996)     

A Radioactive Tracer Technique for the Direct Measurement of the Diffusion Resistance of Stomata

A new method is described for measuring the stomatal resistanceto diffusion in leaves. It consists of measuring the radioactivityof air samples which have diffused through a leaf from a porometercontainer enriched with radioactive argon(⁴¹A). Details of thecalibration are given together with the methods adopted to determinethe accuracy of measurement and the optimum time of sampling.Results suggest that in the material investigated the measurementsobtained are essentially those of stomatal resistance.In onesmall experiment inter and intra plant variability in stomatalresistance was investigated; in another, the diffusion porometerwas used to compare the daily march of stomatal resistance withthe rate of transpiration in plants growing under four differentsoil-moisture regimes.     

Filling biodiversity gaps: benthic hydroids from the Bellingshausen Sea (Antarctica)

The Bellingshausen Sea constitutes the third largest sea in the Southern Ocean, though it is widely recognized as one of the less-studied Antarctic areas. To reduce this lack of knowledge, a survey to study the biodiversity of its marine benthic communities was carried out during the Bentart 2003 and Bentart 2006 Spanish Antarctic expeditions. The study of the hydroid collection has provided 27 species, belonging to ten families and 15 genera. Twenty-one out of the 27 species constitute new records for the Bellingshausen Sea, raising the total number of known species to 37, as also do nine out of the 15 genera. Candelabrum penola, Lafoea annulata, and Staurotheca juncea are recorded for the second time. Most species belong to Leptothecata. Sertulariidae with 13 species (48%) is by far the most speciose family, and Symplectoscyphus with seven species (26%), including S. bellingshauseni sp. nov. and S. hesperides sp. nov., the most diverse genus. Considering the whole benthic hydroid fauna of the Bellingshausen Sea, 18 species (69%) are endemic to Antarctic waters, either with a circum-Antarctic (12 species, 46%) or West Antarctic (6 species, 23%) distribution, 23 (88%) are restricted to Antarctic or Antarctic/sub-Antarctic waters, and only three species have a wider distribution. Bellingshausen Sea hydroid fauna is composed of a relatively high diversity of typical representatives of the Antarctic benthic hydroid fauna, though with a surprisingly low representation of some of the most diverse and widespread Antarctic genera (Oswaldella and Schizotricha), what could be related to the fact that its shelf-inhabiting hydroid fauna remains practically unknown.     

TAXONOMIC REVIEW OF THE TREE SNAIL AMPHIDROMUS ALBERS, 1850 (PULMONATA: CAMAENIDAE) IN THAILAND AND ADJACENT AREAS: SUBGENUS AMPHIDROMUS

Extensive series of Amphidromus Albers, 1850 were collectedfrom low-altitude areas (30–500 m above sea level)in Thailand, Laos, Malaysia, Singapore and Indonesia between1993 and 2004. Data on shell colour, genital and spermatophoremorphology, and radular structure are presented. Five speciesof Amphidromus (Amphidromus) are reviewed, of which four occurin Thailand. Intraspecific variation between populations ofAmphidromus (Amphidromus) atricallosus (Gould, 1843) is considered;three subspecies are accepted and a new subspecies described.Subspecies of A. (A.) inversus (Müller, 1774) and A. (A.)schomburgki (Pfeiffer, 1861) are reconsidered, and a new subspeciesof the latter is described. A dichotomous key to the speciesand subspecies of Amphidromus (Amphidromus) in Thailand is provided. (Received 7 May 2004; accepted 31 March 2005)     

Some Aspects of the Reproductive Biology of Limonium vulgare Mill., and Limonium humile Mill.

The germination of two species of salt-marsh plants Limoniumvulgare Mill., and L. humile Mill., is investigated in relationto their ecology. Germination is inhibited by sea water, butgermination even in fresh water is low. Inhibition of germinationby sea water is negatively correlated with water uptake. However,a treatment in sea water stimulates subsequent germination infresh water. The effect of the sea-water treatment appears tobe one of osmotic shock which weakens the seed coat. Variationin response to the treatment is partly genetical and partlyenvironmental. Seeds in different parts of the salt-marsh willbe subject to differing conditions, both during seed developmentand during the interval between seed maturation and seed dispersal.In connection with this the effect of leaching by sea waterand fresh water is considered. The response to a sea-water treatmentvaries with time. Considered in the long term it shows somecyclical variation which might correspond with the tidal cycle.It is shown that seeds of Limonium can survive long periodsin sea water. There is a slow rate of germination during immersion.Most of those seeds which do not germinate in sea water surviveto germinate rapidly in fresh water. The response to oxygenconcentration, light, and temperature is also investigated.Experiments on seedling growth and establishment show the needfor fresh water and a suitable substrate. Mud gives a lowergermination but a higher survival, while sand gives a highergermination but a lower survival. The dispersal of Limoniumseeds in nature is investigated. Seeds of Limonium are mostabundant in the drift line, but even these only represent asmall fraction of the total produced. It is considered thatreproduction by seed is only important when a new area is beinginvaded. Subsequent reproduction is largely by vegetative spread.The ecological implications of the germination experiments arediscussed.     

A new species of pelagic amphipod of the genus Lestrigonus (Crustacea: Amphipoda: Hyperiidea: Hyperiidae) from eastern Australia

A new species of pelagic amphipod, Lestrigonus ducrayi sp. nov.,from eastern Australia, is described and illustrated. It isvery similar to Lestrigonus bengalensis Giles, 1887, but isreadily distinguished by a relatively shorter telson (aboutone-third peduncle uropod 3) and, in mature males, pereonites1–5 are fused as in females. The two species often occurtogether in the same plankton sample; the new species beingmore abundant inshore, although both species seem to preferinshore waters. A key to the species of Lestrigonus is provided.     

A new species of Acartia (Copepoda, Calanoida) from the Yellow Sea

A new species (Acartia hongi) of Acartia (family Acartiidae)predominating in the Korean coastal waters of the Yellow Seais described. This species closely resembles Acartia bifilosa,from which it can be easily distinguished by the co-occurrenceof the following morphological characters: the absence of rostralfilaments in both genders; the terminal spine on the femalefifth leg toothed only on the inner side; the first exopodalsegment of the male right fifth leg with a long seta; the distalsegment of the male left fifth leg with a rod-like appendage.Its distribution was discussed in comparison with two siblingspecies, Acartia omorii and Acartia hudsonica.     

A REVISION OF BENTHOBROOKULA CLARKE, 1961 (GASTROPODA, TROCHOIDEA) IN THE SOUTHWESTERN ATLANTIC OCEAN

A systematic revision of the species of Benthobrookula Clarke,1961 from the Southwestern Atlantic Ocean was carried out. Theglobose protoconch, sculptured with a reticulate pattern, isrecognized as a diagnostic character for the genus. Benthobrookulaexquisita Clarke, 1961 and B. powelli Clarke, 1961 are redescribedand Cyclostrema calypso Melvill & Standen, 1912, Brookulapfefferi Powell, 1951 and Brookula strebeli Powell, 1951 areredescribed and allocated to Benthobrookula. Benthobrookulastrebeli is validated on the basis of the study of topotypicalspecimens. Two new species are described: Benthobrookula argentinafrom South Georgia and Benthobrookula paranaensis from off Brazil.A new allocation of Scalaria brevis d'Orbigny, 1840 to Benthobrookulais proposed. (Received 14 October 2004; accepted 20 May 2005)     

中国模尖蛾属研究及二新种记述（鳞翅目：尖蛾科）

研究了中国模尖蛾属Meleonoma Meyrick,其中记述2新种：面模尖蛾 M. facialis Li et Wang, sp. Nov. 和软颚模尖蛾 M. malacognatha Li et Wang, sp. Nov.。绘制了雌雄外生殖器特征图,给出了中国模尖蛾属分种检索表。模式标本保存在南开大学生物系标本室。     

Cell Proliferation in the Terminal Regions of the Internodes and Stolons of the Colonial Hydroid Campanularia flexuosa

Pattern formation and cell proliferation have been believedto have a causative relationship in the colonial hydroids. Herelinear stolon growth was assumed to be dependent on polarizedcell proliferation restricted to the extreme end of the stolon.The popularity of the concept that pattern formation was a resultof restricted meristematic cell proliferation was based on acorrespondence between the observed growth patterns and theconcept. Nevertheless, there is little direct knowledge of cellproliferation in the stolons of hydroids. The primary objective of this investigation was to determinethe sites of cell proliferation in the terminal growth zonesof the colonial hydroid Campanularia flexuosa in order to evaluatethis concept. The results give evidence that cell proliferationis more or less uniformly distributed throughout the terminalstolon and the internodes of upright stems, and not restrictedto the tips of the stolons and internodes as has been previouslypostulated. Cell proliferation occurs in both the epidermis and gastrodermisof the stolon in a ratio of 3 to 2. The formation of a new uprightis accompanied by increased cell proliferation localized atthe site of initiation. The uniform distribution of cell proliferation in the stolonsupports the hypothesis that growth is via intercalary cellproliferation, which was proposed eailier on the basis of evidenceobtained from the displacement of vital stained bands of tissuein the stolon. Stolon growth via intercalary cell proliferation requires areconsideration of the factors which control morphogenesis.Wolpert has pointed out the importance of determining the mitoticpattern in a developing system before an understanding of positionalinformation within the system may be studied. Thus, informationfor greater insight into the study of positional informationin a developing hydroid has been obtained.     

A New Genus and Species of the Family Anulidentaliidae (Scaphopoda: Dentaliida) and its Systematic Implications

Shell, radula, and anatomy of Epirhabdoides ivanovi new genusand species are described from a sample of the Russian VitjazExpedition from the Japan Trench. It is distinguished from thesimilar Laevidentalium sominium by shell morphometrics and radulamorphology. The radula is almost identical with that of Anulidentaliumbambusa (Anulidentaliidae). The anatomy of the mantle margins,however, including dorsolateral slits at the anterior mantlemargin and a connective tissue bolster at the posterior mantleopening is that of the family Rhabdidae. In a parsimony analysisEpirhabdoides ivanovi takes an intermediate position betweena basal grade of Gadilinidae and the remaining Dentaliida implyingconvergent evolution of mantle characters. An alternative butless parsimonious tree with E. ivanovi as sister taxon to Rhabdusrequires convergences in radula characters. This is the firstdocumented case of convergent anatomical features among Scaphopodaand enhances the need of radula and soft part investigationof the conchologically little informative, smooth-shelled dentaliidgroups. (Received 16 March 1998; accepted 1 June 1998)