Biological observations on small cyclopoid copepods in the Red Sea

The breeding activity, sex ratio and variation in body lengthof a number of cyclopoid copepod species from the upper 450mof the Red Sea were analyzed. In most species the body lengthof adult specimens was in the lower range or less than thosereported from other pelagic regions. In the central Red Seamost species had some individuals actively breeding, duringboth autumn and winter. To the north, breeding was observedin fewer species. Only two species, Paroithona sp. and Agetuslimbatus, however, seemed to find conditions for reproductionbetter in the north than in the central area. The sex ratioswere quite consistent for all species within the families Sapphirinidaeand Corycaeidae (high percentage of males) and Oithonidae (lowpercentage of males). Within the Oncaeidae, the percentage ofmales varied from a few percent to >60% of adults. Thereappears to be a relationship between sex ratio and size. Populationsof the very small Oncaea species, O.ivlevi, O.prendeli and O.zernovi,include far fewer males than those of their larger congeners.The available information on the biology of Oncaea is summarized.Peculiarities in their life histories and reproduction are discussed.     

Two new Oncaea species (Copepoda: Poecilostomatoida) from the Red Sea

Two new Oncaea species, O.umerus and O.hawii, are describedfrom females taken in the central Red Sea. They are closelyrelated to each other and to a group of Oncaea similis-likespecies, whose morphological characteristics are reviewed forcomparison.     

Vertical structure of small metazoan plankton, especially noncalanoid copepods. I. Deep Arabian Sea

The abundance and vertical distribution of micro-metazoans sampledwith fine nets of 0.05 mm mesh size were studied at three stationsin the Arabian Sea during the intermonsoon period (April/May1987) and down to 1850 m depth. In the epipelagic zone (0–100m). values of biomass and metazoan abundance tended to be higherthan those reported for other tropical oceanic areas. In themesopelagic zone, which is characterized by an extreme oxygendeficiency between 100 and 1000 m depth, the abundance of metazoantaxa and species numbers of non-calanoid copepods were largelyreduced. However, intermediate abundance maxima occurred withinthis zone, which were dominated by specific metazoan taxa (copepods.appendicularians) and species of non-calanoids (Oncaea sp. C).In the bathypelagic zone below 1050 m, the species diversityof the dominant copepod family Oncaeidae increased substantially.Two-thirds of a total of 69 oncaeid species recovered were confinedto this layer. As most of them were small in size and occurredin low abundance only, the increase in total oncaeid densityand/or plankton biomass was less conspicuous. Dominant Oncaeaspecies in the bathypelagic zone were O.longipes and O.brodskii.The results are compared with published data from the ArabianSea and other tropical oceanic areas with and without an extrememesopelagic oxygen minimum zone Possible causes of the intermediateabundance maxima within the oxygen deficiency zone are discussed.     

Observations on the taxonomic composition and vertical distribution of cyclopoid copepods in the central Red Sea

The taxonomic composition and vertical distribution of cyclopoid copepods, including very small species, in the central Red Sea were analyzed. Samples were taken in a multiple opening and closing net with 0.1 mm mesh size to a depth of 450 m. Most species belong to the genus Oncaea (13 identified and 6 unidentified forms). Nearly one half of these are smaller than 0.4 mm in length. Nine cyclopoid species and three groups of very similar species and forms of Oncaea predominate. In the upper 450 m of the water column, each of these species or groups account for more than 1 % of all cyclopoid specimens. In the epipelagic zone (0–100 m) Oithona simplex predominates, accounting for 20 % of the total. In the upper mesopelagic zone Paroithona sp. and one of the unidentified Oncaea forms are most numerous from 100 to 250 m, and two groups of Oncaea are most abundant from 250 to 450 m. The dominance of single species among cyclopoids is less pronounced than that reported for calanoids in the mesopelagic zone of the central Red Sea.     

The microcopepod fauna in the Eastern Mediterranean and Arabian Seas: a comparison with the Red Sea fauna

Multiple opening-closing nets of 0.05 mm mesh size were employed to study the community structure and vertical distribution of microcopepods at selected stations in the Red Sea, Arabian Sea and Eastern Mediterranean Sea down to a maximum depth of 1850 m. Calanoids, cyclopoids (Oithona and Paroithona) and poecilostomatoids (mainly Oncaea) were the 3 most abundant orders. In the epipelagic zone (0–100 m), these orders occurred at similar abundance levels, whereas in the meso- and bathypelagic zones the poecilostomatoid genus Oncaea dominated numerically by about 60–80% of all copepodids.The species diversity of Oncaea in the Red Sea is compared with preliminary results from the two adjacent regions. In the deep Eastern Mediterranean Sea, the number of species appears to be similar to that in the deep Red Sea and low as compared to the deep Arabian Sea. In this latter area an extremely speciose Oncaea fauna was found at depth below the oxygen-minimum-zone (900–1850 m). The results are related to the differences in the hydrographic conditions of these 3 areas.     

Vertical zooplankton distribution on the northeastern Florida shelf and its relation to temperature and food abundance

The vertical distribution of abundant zooplankton on the northeastern(NE) Florida shelf was measured and related to depth, temperatureand concentration of particulate matter. High particle concentrationswere observed in low-temperature near-bottom intrusions of upwelledGulf Stream water. Patterns of vertical distribution differedamong the abundant zooplankton taxa. Abundances of the calanoidsEucalanus pileatus and Temora turbinata, late copepodids andadults of the cyclopoid Oncaea sp., the cladcceran Penilia avirostrisand larvae of the cephalochordate Branchiostoma sp. generallyincreased with increasing depth. E. pileatus, T. turbinata,Oncaea sp. and P. avirostris increased with increasing concentrationof paniculate matter. Abundances of young specimens of the tunicateOikopleura, the calanoid Centropages furcatus and during oneperiod, the cyclopoid Oithona sp. were greatest in the uppermixed layer and the thermocline. The abundance of Eucalanus,T. turbinata and the late copepodids/adults of Oncaea showeda significantly positive conelation to the abundance of paniculatematter.     

THE BIOLOGY OF THE NORTHEASTERN PACIFIC TURRIDAE II. OENOPOTA

The habitat, diet, some reproductive and mortality factors forseveral shallow-water species of the boreal turrid genus Oenopotafrom the Puget Sound region were determined. All fed exclusivelyon tubicolous polychaetes. Oenopota fidicula was a dietary andhabitat generalise Oenopota elegans eats Schistocomus hiltoniand lives in areas of shell fragments. Oenopota excunata eatsTharyx multifilis and is a habitat generalist. Oenopota tabulataappears to be a dietary generalist, but lives only on or nearrocks. The widely-distributed species, O. levidensis, eats spionidpolychaetes, primarily Polydora species, or Owenia fusiformis,and is a habitat generalist. Feeding frequencies are low asare population densities; although O. levidensis sometimes exceeds15 animals m^–2. Crabs are major predators upon turridsin some areas, but mortality causes are generally obscure. Spawningwas observed in four species, but only O. elegans and O. levidensishad viable larvae. Development takes 13–15 weeks, 6–7weeks in a capsule and 6–7 weeks as planktonic veligers.There are no nurse eggs. Settling was not observed. ^*Present mailing address: Bamfield Marine Station Bamfield,B.C. VOR 1B0 CANADA (Received 30 May 1982;     

Photosynthesis and photorespiration in the genus Oryza

Photosynthetic gas exchange has been surveyed in 22 of the 23species currently placed in the genus Oryza and constitutingthe wild relatives of cultivated rice. Unimproved, wild germplasmof a number of species showed light-saturated assimilation ratesin atmospheric air at least as great as cultivars and elitebreeding material of the cultigen O. satlva. One of these specieswas O. australiensis, different accessions of which were significantly(P=0.001) superior in assimilation rate to the 0. satlva genotypestested, including representatives of the Indica, Japonica andJavanica subgroups. Amongst species, assimilation rate was correlatedpositively with light saturation and with carboxylation efficiency.The wild species fell into two distinct groupings accordingto whether they originated from sun or shade habitats, withthe higher assimilation rates being associated with the sunspecies. Assimilation rates were also higher in diploids thanin tetraploids and this was associated with the fact that allsun species are diploids and all tetraploids are shade species.The carbon dioxide compensation concentrations ranged from 28to 43µmol mol^–1 with the two lowest values (28 and32µmol mol^–1) coming from accessions of O. rufipogon.The mean value for the absolute quantum yield of photosynthesismeas ured on attached leaves was 0.060. There was a large rangein the activity of phosphoenolpyruvate (PEP) carboxylase witha number of species having rates several times those of C₃ species.Some species with the highest assimilation rates were assessedfor photorespiratory losses and these were generally around30% and similar to O. satlva cultivars. However, a range ofO. rufipogon accessions had photorespiration rates significantly(P=0.01) lower than the O. sativa genotypes tested. No speciesin the genus possessed C₄ photosynthetic metabolism though somedid overlap with compensation concentrations and phosphoenolpyruvatecarboxylase activities reported for C₃–C₄ intermediatespecies. The potential value of wild relatives to the improvementof cultivated rice is discussed. Key words: Oiyza, photorespiration, photosynthesis, rice, wild rice     

Reassessment of the Systematic Status of Miamira Bergh, 1875 and Orodoris Bergh, 1875 (Nudibranchia: Chromodorididae) in Light of Phylogenetic Analysis

The external morphology and anatomy of the opisthobranch gastropodsMiamira sinuata (van Hasselt, 1824) and Orodoris miamiranaBergh, 1875, the type species of the genera Miamira Bergh, 1875and Orodoris Bergh, 1875, and their phylogenetic relationshipsare studied. The phylogeny obtained supports the placement ofM. sinuata and O. miamirana in the genus Ceratosoma J. E. Gray, 1850.Therefore, Miamira and Orodoris become synonyms of the seniorvalid name Ceratosoma. In addition, the family name MiamiridaeBergh, 1891, based on Miamira, is newly recognized as a synonymof Chromodorididae Bergh, 1891. Ceratosoma sinuata and C. miamirana are more closely relatedto the highly derived Ceratosoma alleni than to other membersof the genus. C. miamirana appears to present reversal to theplesiomorphic state in the body shape and has secondarily lostits mantle glands. (Received 5 January 1998; accepted 23 April 1998)     

Mesozooplankton associations with medium to large marine snow aggregates in the northern Gulf of Mexico

Large and diverse mesozooplankton communities were observedon marine snow particles collected in coastal and oceanic watersof the northern Gulf of Mexico. Mesozooplankton were collectedfrom seven phyla, including ostracods, cladocerans, pelecypodsand ascidian larvae not previ ously recorded as being associatedwith marine snow. Copepod nauplii were the most common, sometimesat concentrations >100 per aggregate. Oncaea spp., Oithonaspp. and Microsetella norvegica were the most common copepodspecies. Total mesozooplankton abundance ranged between 2 and278 organisms per aggregate. Organisms varied markedly in theirdistribution across the aggregate surface and in their behaviourtowards the snow matrix. Comparison of snow communities withzoo-plankton abundance determined from net tows suggests thatsome species are concentrated on snow particles. Snow particlesand their associated microbial communities may be a significantsource of nutrition for these mesozooplankton. Mesozooplanktonmay contribute significantly to the degra dation and decompositionof large snow particles as they sink through the upper watercolumn.     

A survey for body scales in dinoflagellates and a revision of Cachonina and Heterocapsa (Pyrrhophyta)

Small organic scales 0.2 to 0.4 µm in diameter have beenobserved to form a layer on the surface of three species ofmarine dinoflagellates. Two of the species were originally describedas members of the genus Cachonina; the third is Heterocapsapygmaea Loeblich et al., 1981. The body scales are very similarto those previously described covering cells of Heterocapsatriquetra (Ehrenberg) Stein, 1883. These scales are freely shedfrom the cells of the above four species and can be found inthe culture medium; no scales were observed in the culture mediumof 35 other dinoflagellate species representing 18 genera and11 families. The complete thecal plate pattern of H. triquetra,type species of Heterocapsa, has been determined, and on thebasis of similarities in body scale morphology and thecal platetabulation, the genus Cachonina is placed in the synonomy ofHeterocapsa. Cachonina illdefina and C. niei are transferredto Heterocapsa.     

FURTHER STUDIES ON THE TAXONOMY AND BIOLOGY OF THE OCTOCORAL-FEEDING GENUS PHYLLODESMIUM EHRENBERG, 1831 (NUDIBRANCHIA: AEOLIDOIDEA)

The aeolid nudibranch genus Phyllodesmium (Mollusca: Gastropoda)is reviewed, three new species are described and further informationon the biology, anatomy and distribution on the eight previouslyknown species is reported. The genus Ennoia Bergh, 1896 is considereda synonym of Phyllodesmium and the type species Ennoia briareusredescribed. The genus Phyllodesmium is unique amongst the aeolidsin feeding on octocoral cnidarians. This has led to the evolutionof nudibranch- zooxanthellae symbioses, zooanthellae being obtainedfrom the octocoral prey. The adaptations developed throughoutthe genus are described and possible relationships between thespecies proposed. (Received 6 January 1990; accepted 20 May 1990)     

A NEW GENUS AND SPECIES OF PLANORBIDAE (GASTROPODA: HETEROBRANCHIA: PULMONATA) FROM NORTHERN AUSTRALIA

A new genus and species of Planorbidae, Kessneria papillosa n.gen.and sp. from the Northern Territory, Australia, are described.The new genus is morphologically most similar to Leichhardtia,another genus restricted to Northern Australia, from which itdiffers in a number of important shell and anatomical characters.The shell of the new genus differs from all other planorbidsin having a raised, papillate protoconch, and is also uniqueamongst Australian high-spired genera in being umbilicate and inhaving a sinuate outer lip. (Received 12 May 2000; accepted 25 September 2000)     

Armoured dinoflagellates in the NE Atlantic during the BOFS cruises, 1988-90

The armoured dinoulagellates present in 90 plankton samplescollected by the use of an Apatein closing net were enumerated.The samples were collected from various stations around the20W meridian and between 44 and 60N during the 1988, 1989and 1990 Biogeochemical Ocean Flux Study (BOFS) cruises. Atmost stations, samples were obtained from various depths, althoughin 1990 only the surface zone was sampled. A total of 126 specieswere identified, of which 49 have chloroplasts and are thoughtto be autotrophic, 47 are assumed to be heterotrophic and thenutritional type of the remainder is unknown. The samples collectedduring July 1988 were dominated by large numbers of the twophotosynthetic species Gonyaulax polygramma and Protoceratiunreticulatum (=Gonyaulax grindleyi). The much more intensivesampling of 1989 revealed several Ceratiun species, C.fusus,C.furca and C.lineazum, together with Gonyaulax polygramma,as the most common dinoflagellates. In 1990 the samples, whichwere taken during a Lagrangian survey in May-June, were alsodominated by Ceratium species. This time C.azoricwn was a majorcomponent and Protoceratium reticulatum was again present inhigh numbers as in 1988. A number of analyses were carried outon the data collected. It was found that the majority of themore frequent species were autotrophs and most were membersof the genus Ceraziwn. The effects of depth were shown to resultin reduced numbers of cells and species, but no clear associationwas found between species and depth. After the application ofDetrended Correspondence Analysis (DECORANA) to all surfacesamples, there was found to be a clear association between thespecies composition and both time of year and latitude. Watercolumn stability is also probably an important factor in speciescomposition and cell numbers. Seasonal changes in the frequencyof the main species were also noted with some, such as C.lineatum,being more important early in the summer and others, such asProtoceratium reticulatum and particularly G.polygramma, becomingdominant later. The use of Two-way Indicator Analysis (TWINSPAN)revealed some potential species associations.     

MAINWARINGIA NEVILL, 1885, A LITTORINID GENUS FROM ASIATIC MANGROVE FORESTS, AND A CASE OF PROTANDROUS HERMAPHRODITISM

On the basis of reproductive anatomy and radula, the poorlyknown genus Mainwaringia Nevill, 1885, is shown to belong tothe Littorinidae. The genus is represented by two species, M.leithii (E.A. Smith, 1876) from India to Vietnam, and a newspecies, M. rhizophila, from Malaysia to Hong Kong. Both occurin mangrove forests. The reproductive anatomy of M, rhizophilais described in detail, and it is interpreted as a protandroushermaphrodite, a condition unique in the Littorinacea. In theintersexual and female stages both closed pallial oviduct andopen prostate are present in the mantle wall, suggesting thatthese structures are not strictly homologous. The affinitiesof Mainwaringiaare discussed, and it is concluded that it maybe most closely related to Littorina s.s. (Received 30 May 1986;     

HAMINAEA EXIGUA (GASTROPODA, OPISTHOBRANCHIA), A NEW CEPHALASPID SPECIES FROM THE MEDITERRANEAN SEA

A new species of the genus Haminaca has been found in samplesfrom the northern Adriatic Sea. The new species is very similarto H. orteai, but may be clearly distinguished by body size,the non-pigmented area around the eyes, number of leaves ofHancock's organ, number of ridges on the gizzard plates andby the morphology of male genital tract. A comparison and adiscussion of the values of the most significant characterswithin the genus Haminaca is provided herein. (Received 19 September 1991; accepted 28 February 1992)     

Recent bivalve molluscs of the genus Calyptogena (Vesicomyidae)

The genus Calyptogena (Bivalvia: Vesicomyidae) comprises highlyspecialized bivalves living in symbiosis with sulphur-oxidizingbacteria in reducing habitats. In this study, the genus is revisedusing shell and anatomical features. The work is based on typematerial, as well as on the extensive collection of vesicomyidsobtained during twelve expeditions to the Pacific and IndianOceans. Nine Recent species are ascribed to the genus Calyptogena,four of which are new: C. pacifica Dall, 1891, C. fausta Okutani,Fujikura & Hashimoto, 1993, C. rectimargo Scarlato, 1981,C. valdiviae (Thiele & Jaeckel, 1931), C. gallardoi Sellanes& Krylova, 2005, C. goffrediae n. sp., C. starobogatovin. sp., C. makranensis n. sp. and C. costaricana n. sp. Thecharacteristic features of Calyptogena are: shell up to 90 mmin length, elongate-elliptical or elongate; presence of escutcheon;presence of broad posterior ramus (3b) of right subumbonal cardinaltooth as well as right posterior nymphal ridge; absence of pallialsinus as a result of attachment of intersiphonal septal retractorimmediately adjacent to ventral surface of posterior adductor;absence of processes on inner vulva of inhalant siphon; presenceof inner demibranch only, with descending and ascending lamellaewith interlamellar septa not divided into separate tubes. Themost closely related taxa to Calyptogena are probably the genusIsorropodon Sturany, 1896, and the group of species representedby ‘Calyptogena’ phaseoliformis Métivier,Okutani & Ohta, 1986. These groups have several charactersin common, namely absence of pallial sinus, presence of singleinner pair of demibranchs and absence of processes on innervulva of inhalant siphon. The worldwide distribution of thegenus Calyptogena suggests that methane seeps at continentalmargins are the major dispersal routes and that speciation waspromoted by geographical isolation. Recent species diversityand fossil records indicate that the genus originated in thePacific Ocean. Sufficient data to discuss the distribution atspecies level exist only for C. pacifica, which has a remarkablynarrow bathymetric range. Published studies on the physiologyof C. pacifica suggest that adaptation to a specific geochemicalenvironment has led to coexisting vesicomyid genera. The bacteria-containinggill of C. pacifica and other Calyptogena species is one ofthe most specialized in the family Vesicomyidae and may reflectthese ecological adaptations. (Received 23 December 2005; accepted 3 April 2006)     

A Study of Genetic Variation and Relationships within the Bamboo Subtribe Bambusinae using Amplified Fragment Length Polymorphism

Taxonomic and systematic studies of the woody bamboos are traditionallybased on floral morphology, which can cause problems in identificationdue to the lack of, or infrequent, flowering. Limited studieshave been conducted using molecular techniques to overcome thisproblem. In this study, we used amplified fragment length polymorphisms(AFLPs) to conduct a study of four genera of bamboos (Bambusa,Dendrocalamus, Gigantochloa andThyrsostachys ) in the subtribeBambusinae. AFLP analysis using eight primer combinations wascarried out on 15 species of bamboo. Results showed that AFLPsdistinguish the different species by their unique banding patterns.Unique AFLPs were detected in 13 of the 15 species examined.The six Bambusa species examined separated into two clusters.The sixGigantochloa species studied formed a discrete clusterdiverging from one of the Bambusa clusters, whileThyrsostachyswas less similar to the Bambusa clusters. The similarity indexbetween B. lako and G. atroviolacea was the highest, suggestingthat B. lako is more appropriately included within the genusGigantochloarather than the genus Bambusa. The two Dendrocalamus speciesexamined were very different with D. brandisii clustering withinone of the Bambusa clusters and D. giganteus appearing as avery distant species. These results support the contention thatcritical study of the genus Dendrocalamus is required. The useof AFLPs for identification of particular bamboo species, aswell as for the study of relationships within the subtribe,will be useful for industrial purposes and for systematic studies.Copyright 2000 Annals of Botany Company Bamboo, Bambusinae, Bambusa, Gigantochloa, Dendrocalamus, Thyrsostachys, AFLP, diversity, AFLP markers     

ANATOMY OF SOME INDO-PACIFIC ELYSIIDAE (OPISTHOBRANCHIA: SACOGLOSSA (=ASCOGLOSSA)), WITH A DISCUSSION OF THE GENERIC DIVISION AND PHYLOGENY

The Elysiidae is the largest family of Sacoglossa (=Ascoglossa)(Mollusca, Opisthobranchia). The Indo-Pacific fauna containsabout 65 species presently referred to the genus Elysia. Almostnothing is known about the internal anatomy of these animals.In the present study the internal anatomy, particularly thepharyngeal musculature, morphology of radularteeth, and reproductivesystems, of 12 Indo-Pacific elysiids is investigated. Also,the internal anatomy of the Mediterranean type species of thegenera Elysia and Thuridilla is described. On this basis, thevalidity of the genera Elysia, Thuridilla, Elysiella and Pattyclaya,is confirmed. Also, the genus Placobranchus is transferred tothe Elysiidae. phylogenetically important characters are identifiedand phylogenetic relationships within the family are discussed. (Received 10 April 1991; accepted 28 December 1991)     

蜱类系统学研究进展

本文介绍了近年来蜱的编目和分类及系统发育和演化等方面的研究进展。对软蜱科(Argasidae)说明了属的变动;硬蜱科(Ixodidae)介绍了璃眼蜱亚科(Hyalomminae)和凹沟蜱亚科(Bothriocrotoninae)以及相应变动的属(新建的凹沟蜱属Bothriocroton和须角蜱属Cornupalpatum,合并的牛蜱属Boophilus、暗眼蜱属Anocentor和盲花蜱属Aponomma)。根据新的分类变更对已知种类进行了分析。至2006年,世界已知蜱类有3科18属897种,中国有2科10属119种。阐明了有关蜱类系统发育研究的主要观点,并讨论了其不足和有待深入研究的问题。目前,把形态学和分子生物学数据结合在一起的全证据方法,并结合蜱类和不同宿主之间的关系、动物地理学、古生物学以及比较寄生虫学的资料,成为解决蜱类系统发育问题的有效途径。