Flood circulation in oligomictic lakes: an undervalued reason for restriction of zooplankton production [Translation from: Memorie dell'Istituto Italiano di Idrobiologia Dott.Marco de Marchi 22 9-52, 1967]

Dormancy has been observed in several species of Cyclops. Animals in dormancy are characterised by almost complete inactivity of the main appendages and sluggish intestinal peristalsis. In Cyclops vicinus dormancy can take place in copepod stages III (19%), IV (78%) and V (3%) but one and the same animal only in one developmental stage. The author gives his own results between frequency of dormancy and photoperiod (20 C, 1000 lux). He concludes that dormancy in C. vicinus can be influenced by day length and can be ended prematurely by short day length.

Desarrollo larval de dos especies de Crustáceos Decápodos en el laboratorio, Pachycheles haigae Rodrigues Da Costa (Porcellanidae) y Chasmagnathus granulata Dana (Grapsidae)

The present paper is concerned with studies on the larval development of two species of crustacean Decapoda: Pachyceles haigae Rodrigues Da Costa, 1960 family Porcellanidae and Chasmagnathus granulata Dana, 1851, family Grapsidae. One preazoea, two zoeae with a total of five sub-stages, a and b, and the second zoea had sub-stages a, b and c. The greatest changes are observed in the transition from the first to the second zoea and from this to the megalopa. During the sub-stages, there occured minor changes, and a net moulting of the cuticle is not observed. The differences in these sub-stages are marked by changes in the number and shape of the appendages.

Changes in egg production of the western rock lobster (Panulirus cygnus) associated with appendage damage

Data collected during fish-ery-independent sampling programs were used to examine the impact of appendage damage (indicated by lost or regenerated legs and antennae) on the reproductive output of female western rock lobster (Panulirus cygnus). Most of the damaged females sampled had one (53%), two (27%), or three (13%) appendages that had been lost or that were regenerating. Appendage damage was associated with the reduced probability of a female developing ovigerous setae; and if setae were produced, with the reduced probability that females would produce more than one batch of eggs within a season. These effects were more pronounced as the number of damaged appendages increased. From data collected in 2002, it was estimated that the total number of eggs produced by mature females caught in the fishery was significantly reduced (P<0.001) by 3–9% when the impact of appendage damage was included.

Identification and culture of common diatoms as possible feed for Penaeus monodon

Diatoms were collected from Buyuan Bay, and from the hatchery tanks at Tigbauan, to determine the commonly occurring species, the feasibility of culturing these species, and the potential of these selected species as food for larval P. monodon. The commonly occurring diatoms were identified as Chaetoceros calcitrans, Navicula grimmei, Nitzchia seriata, Nitzchia closterium and Amphiprora sp. These diatoms were isolated and unialgal cultures prepared. Protein content analysis using the micro-Kjildahl method gave the following result: C. calcitrans, 11 . 78%; Nitzchia seriata, 25%; Nitzchia closterium, 30 . 5%; Navicula grimmei, 9 . 06% and Amphiprora sp. 8 . 96%. Feeding experiments were conducted to determine acceptability of the different diatom species and percentage survival of larval stages Z SUB-1 -M SUB-2 . Larvae were placed in 4-l capacity plastic containers with a stocking density of 10/l. The results of several feeding trials using the different mass-produced diatoms are summarized. From the data gathered, C. calcitrans appears to be the most promising candidate as feed for zoea and mysis stages of P. monodon. The average percentage survival of C. calcitrans was 63 . 76% for the 3 trials, and as high as 82 . 22% in the third trial. Comparatively high percentage survival of larvae was also recorded when Nitzchia seriata (48 . 17%) and Nitzchia closterium (67 . 6%) were given as feed, while both Amphiprora sp. and Navicula grimmei gave 0% survival. The poor results with Amphiprora sp. and Navicula grimmei may be due to their low protein content (8 . 96% and 9 . 06%, respectively) and the inability of the larvae to ingest them. Navicula and Amphiprora were observed to cling to the appendages of the larvae and to settle down in the medium making them unavailable to the larvae. Low survival was also noted when frozen C. calcitrans was used (14 . 25%). This may be due partly to the effect of the floculating agent (ALSO SUB-4 . 25 g/l) used in concentrating the diatoms. When protein contents of C. calcitrans, N. seriata and N. closterium are compared, the 2 Nitzchia species have relatively higher protein contents than C. calcitrans and, therefore, could be the more desirable feed candidates. However, few feeding trials were made using Nitzchia so that additional investigations will have to be done on this aspect.

La estructura y reproducción de Acanthococcus antarcticus Hooker et Harvey

The present paper gives a full description of the organization of Acanthococcus antarcticus Hooker et Harvey, a not well known member of the Rhodophyllidaceae as well as gives for the first time description of the male and tetrasporic plants. Detailed organization of the carpogonial branches, spermatia and tetraspores is also presented. Nineteen figures illustrate the text (material collected at Deseado port, Santa Cruz prov., Argentina). The following text is the content of the discussion. From the description it is possible to confirm the position of Acanthococcus in the Rhodophyllidaceac as was done by Kylin (Kylin 1960, p. 290 et seg.). It has many similarities in the development of the carpogenic branches and in the formation of spermatia as well in the production of the zonately divided tetrasporangia with the genera of the family whose reproduction is known; Cystoclonium purpureum (Hudson) Batters and Rhodopyllis bifada (Good. et Woodw.) Kützing (Kylin 1923); Calliblepharis jubata (Good. et Woodw.) Kützing (Kylín 1928) and Craspedocarpus erosus (Hook. et Harvey) Sehmitz (Kylin 1932). Apparently the distinguishing feature of Acanthococcus is the structure of the vegetative frond, with the abundant development of rhizoidal filaments in the medula, besides the characteristic appendages of the cystocarps. Harvey's figure (Harvey 1847, P. 181, Fig. 3) of the tranverse section of the plant shows the central portion composed of a dense small-celled medula limited by a region of large cells which is externally covered by a small-celled cortex. As we have seen the small-celled filaments are not restricted to the central portion, but extend into the large-celled portion and can reach the cortex. On the other hand, the eros section of Acanthococcus depicted by Kützing (Kützing 1867, T. 93, Fig. h, under Callophyllis antartica), apparently belongs to another plant, so different in the structure when one compares his figure with Harvey's and the ones in this paper. RESUMEN EN ESPAÑOL Este trabajo presenta una completa descripción de la organización de Acanthococcus antarcticus Hooker et Harvey, un miembro poco conocido de las Rodofilidáceas, así como presenta por primera vez descripciones de las plantas masculinas y de las tetraspóricas. También por primera vez es presentada la organización detallada de las ramas carpogoniales, de los espermecios y de las trásporas. Diecinueve figuras completan el texto (material coleccionado en Puerto Deseado, Prov. Santa Cruz, Argentina).

Fridericia liangi sp nov (Enchytraeidae, Oligochaeta) from Changbaishan Mountain, China

We describe one new enchytraeid species, Fridericia liangi sp. nov., from Mt. Changbaishan, Jilin Province, northeastern China. It was collected from soils at the foot of Changbaishan Mountain and is distinguished from all known congeners by the following combination of characters: 1) no lateral chaetae, only ventral chaetae throughout, 2) a maximum of four chaetae in ventral preclitellar bundles, 3) one chaeta in ventral postclitellar bundles, 4) dorsal pores from VII on, 5) esophageal appendages unbranched, 6) coelomocytes without refractile vesicles, 7) clitellum girdle shaped, well developed, 8) no subneural glands, and 9) spermathecae simple.

Fridericia dianchiensis sp nov (Enchytraeidae, oligochaeta) from Yunnan Province, China

Fridericia dianchiensis, a new enchytraeid species collected from Yunnan Province, is described here. It is characterized by a combination of the following characters: 1) lateral bundles containing maximum 3 chaetae; 2) esophageal appendages with 3-4 simple, terminal branches; 3) dorsal vessel originating in XX-XXIII; 4) sub-neural glands absent; 5) seminal vesicle large, occupying two segments; 6)clitellum girdle-shaped or gland cells absent between bursal slits and pre-middle ventrally; 7) coelomocytes without refractile vesicles, 8) spermatheca without diverticula and both ampullae broadly united; and 9) long spermathecal ectal duct without gland at the orifice.

A taxonomic study of Oconnorella (Enchytraeidae, Oligochaeta) from Changbaishan Mountain, China

We describe three enchytraeid species, including two new species, from Mt. Changbaishan, Jilin Province, northeastern China. Oconnorella cheni sp. nov. is characterized by a simple spermatheca; absence of the oesophageal appendages and seminal vesicle; and nephridia from 6/7, with a distinct funnel and the efferent duct arising from the anterior part of the postseptale. Oconnorella globula sp. nov. is distinguished by a spermatheca with two diverticula; lack of oesophageal appendages and seminal vesicle; and nephridia from 6/7, with distinct funnel and the efferent duct arising from the mid-ventral or posteroventral part of the postseptale. We redescribe Oconnorella changbaishanensis (Xie et al., 2000) from type and live specimens, and amend some characters that cannot be investigated clearly from mounted specimens. We revise the generic diagnosis of Oconnorella.

Four new terrestrial species of Marionina (Clitellata, Enchytraeidae) from China and re-examination of M. hoVbaueri Moller

Enchytraeid surveys were made in China, mainly along the Changjiang (Yangtze) River Basin, during the period 1991-1999. Among the findings, four terrestrial species of Marionina are new to science and well illustrate the taxonomic complexity of the genus as currently defined. Marionina sinica sp. n. is characterized by a specific chaetal distribution, the marionine pattern of the dorsal blood vessel, and elongate, fusiform, spermathecal ectal ducts. Marionina sacculata sp. n. is distinguished by the possession of a pair of pouch-like oesophageal appendages in IV, the lack of lateral chaetae in VII-XI, a marionine pattern of the dorsal blood vessel, and short spermathecal ectal ducts gradually expanding into spherical ampullae. Both M. sinica and M. sacculata have minute bodies (2-3 mm long in vivo) and lack spermathecal accessory glands. The former species shows its closest aYnities with the European M. brendae Rota, 1995, whereas the latter is closest to the German M. hoVbaueri Moller, 1971, for which an amended diagnosis is provided. Marionina seminuda sp. n. has only ventral chaetal bundles, distributed from III onwards and bisetose. It is similar to the Holarctic M. subterranea (Knollner, 1935) in lacking entirely the lateral chaetae and in having the brain incised posteriorly, the dorsal vessel bifurcating behind the pharynx, and coelomocytes containing opaque granules, but diVers from it in having the longest chaetae in preclitellar segments and gland cells distributed all over the spermathecal ectal ducts. Marionina righiana sp. n. is diagnosed by the location of the head pore on the prostomium, the absence of lateral chaetae from VIII ( VII or IX) onwards, the possession of free spermathecae extending backwards through one to four segments, the brain deeply incised posteriorly, the lumbricilline pattern of the dorsal blood vessel, and the opacity of coelomocytes in vivo. Prior to this study, members of the genus so atypical as M. righiana with respect to the position of the head pore and the structure of the spermathecae were known only from South American soils. Until the taxonomy of Marionina has been more thoroughly assessed and revised, the assignment of the four species to this large assemblage should be regarded as tentative.

High order liquid crystalline structure of poly(11-{[(4 '-heptyloxy-4-biphenylyl)carbonyl]oxy}-1-undecyne)

Liquid crystalline properties of a mesomorphic polyacetylene {-[HC=C(CH2 )(9)OOC-Biph-OC7H15](n)- (PA9EO7), Biph=4-4'-biphenylyl} are investigated by X-ray diffraction, polarizing optical microscope, and transmission electron microscope. Polyacetylene PA9EO7 from solution adopts a sandwich structure, which is a high order smectic phase. The biphenylyl pendants pack in a hexagonal fashion and the distance between two appendages is 4.51 Angstrom. The heptyloxy tails on one polymer backbone overlap with those on the neighboring chain. The nonyl spacer and the heptyloxy tail exhibit a hexagonal packing arrangement with intermolecular distance of 3.24 Angstrom.

Floral Organogenesis and Development of two Taxa in Tribe Hyoscyameae (Solanaceae)-Przewalskia tanguitca and Hyoscyamus niger

Floral organogenesis and development of Przeivalskia langutica Maxim, endemic to China and Hyoscyamus niger L. , which belong to the tribe Hyoscyameae (Solanaceae), were studied using scanning electron microscope. They have three common characters of floral organ initiation and development: 1) initia-tion of the floral organs in the two species follows Hofmeister's rule; 2) the mode of corolla tube development belongs to the "late sympetaly" type; 3) primordia of the floral appendages initiated in a pentameroua pattern and acropetal order. But initiation of the calyx-lobe primordia showed different modes in these two species. The calyx-lobe primordia of H, niger have simultaneously whorled initiation, while those of P, tangulica have helical initiation, but the five calyx-lobe primordia form a ring after all five calyx-lobe primordia occur. The systematic significance of the present results in the genera Hyoscyamus and Przeivalskia is discussed in this paper.

Embryology of Swertia (Gentianaceae) relative to taxonomy

The embryological features of three species of Swertia (s.l.) - S. erythrosticta, S. franchetiana, and S. tetraptera were characterized, and the observations were used, together with previously gathered data on other species, to evaluate a recently proposed polyphyly, based on molecular data, of Swertia s.l. Comparisons of species within the genus showed that they have diversified embryologically, and there are significant between-species differences. Notable features that vary between species include the number of cell layers that form the anther locule wall, the construction of the wall of the mature anther, tapetum origin, the cell number in mature pollen grains, the structure of the fused margins of the two carpels, the ovule numbers in placental cross-sections, the shape of the mature embryo sac, the degree of ovule curvature, antipodal variation and the presence of a hypostase, and seed appendages. They share characters that are widely distributed in the tribe Gentianeae, such as a dicotyledonous type of anther wall formation, a glandular tapetum with uninucleate cells, simultaneous cytokinesis following the meiosis of the microsporocytes, tetrahedral microspore tetrads, superior, bicarpellary and unilocular ovaries, unitegmic and tenuinucellar ovules, Polygonum-type megagametophytes, progamous fertilization, nuclear endosperm, and Solanad-type embryogeny. The presence of variation in embryological characters amongst the species of Swertia s.l. strongly supports the view that Swertia s.l. is not a monophyletic group. Frasera is better separated from Swertia s.l. as an independent genus, and is only distantly related to Swertia s. s. judging from the numerous differences in embryology. Swertia tetraptera is very closely related to Halenia, as they show identical embryology. (C) 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155, 383-400.

Floral organogenesis and development of two taxa of the Solanaceae - Anisodus tanguticus and Atropa belladonna

Floral organogenesis and development of two Solanaceae species, Anisodus tanguticus and Atropa belladonna, were studied by using scanning electron microscopy (SEM) as part of a project on systematics and evolution in the tribe Hyoscyameae. These two species share the following common characters of floral organ initiation and development: (1) initiation of the floral organs in the two species follows Hofmeister's rule; (2) the mode of corolla tube development belongs to the "late sympetaly" type, namely, petals are initiated separately and later become joined by fusion of their basal meristem, then rise together and form a corolla tube; (3) primordia of the floral appendages are initiated in a pentamerous pattern and acropetal order: sepals are initiated first, followed by the petals and stamens, and finally the carpels. The whorl of five stamen primordia forms almost simultaneously and originates opposite the sepal primordia, but initiation of the sepal primordia shows different modes in the two species. The sepal primordia of Anisodus tanguticus have simultaneously whorled initiation, while those of Atropa belladonna have helical initiation. The systematic significance of the present results in the genera Anisodus and Atropa is discussed in this paper.

A preliminary analysis of the phylogeny of the Swertiinae (Gentianaceae) based on ITS data

To better understand the floral diversity and the phylogeny of the Swertiinae (Gentianaceae), the internal transcribed spacer (ITS) region of nrDNA for 17 species and one outgroup was sequenced. Our data suggest that corolla type, gland shape, and corolla appendage are poorly correlated with the ITS phylogeny. The genus Swertia s.l. and the rotate group previously recognized based on the corolla types and gland shapes are polyphyletic. Four genera with simple protruding glands and three taxa with corolla appendages are not clustered as the monophyletic groups. Four separate clades, corresponding to the four sections, were identified in Swertia s.1. Lomatogoniopsis with the simple protruding gland type of the tubular group closely related to Lomatogonium of the rotate group. The deeply lobing corolla and concave foveae may be ancestral in the Swertiinae, while the tubular corolla and the protruding glands may have undergone convergent evolution.

Dynamic evolution of the alpha (α) and beta (β) keratins has accompanied integument diversification and the adaptation of birds into novel lifestyles.

BACKGROUND: Vertebrate skin appendages are constructed of keratins produced by multigene families. Alpha (α) keratins are found in all vertebrates, while beta (β) keratins are found exclusively in reptiles and birds. We have studied the molecular evolution of these gene families in the genomes of 48 phylogenetically diverse birds and their expression in the scales and feathers of the chicken. RESULTS: We found that the total number of α-keratins is lower in birds than mammals and non-avian reptiles, yet two α-keratin genes (KRT42 and KRT75) have expanded in birds. The β-keratins, however, demonstrate a dynamic evolution associated with avian lifestyle. The avian specific feather β-keratins comprise a large majority of the total number of β-keratins, but independently derived lineages of aquatic and predatory birds have smaller proportions of feather β-keratin genes and larger proportions of keratinocyte β-keratin genes. Additionally, birds of prey have a larger proportion of claw β-keratins. Analysis of α- and β-keratin expression during development of chicken scales and feathers demonstrates that while α-keratins are expressed in these tissues, the number and magnitude of expressed β-keratin genes far exceeds that of α-keratins. CONCLUSIONS: These results support the view that the number of α- and β-keratin genes expressed, the proportion of the β-keratin subfamily genes expressed and the diversification of the β-keratin genes have been important for the evolution of the feather and the adaptation of birds into multiple ecological niches.