Reproductive ecology of dioecious Siparuna (Monimiaceae) in Ecuador–a case of gall midge pollination

The reproductive ecology of the dioecious genus Siparuna , belonging to the primitive family Monimiaceae, was investigated in Ecuador. Thirteen species were studied, and species growing at high altitudes (above 500 m) were compared with species growing at lower altitudes. The genus has specialized flowers pollinated by Cecidomyiidae (Asynapta sp. and other genera) that lay eggs chiefly in male flowers since these are more easily accessible than female flowers due to their morphology. Several traits ensure that pollen transfer is accomplished: 1. long flowering of individuals and single flowers; 2. specific floral morphology (unisexuality, landing platform, restricted pore) allowing the flowers to be visited by Cecidomyiidae seeking egg-laying sites, and 3. a low number of ovules that have to be pollinated in each flower. The low number of ovules per flower results in a high pollen-ovule (P/O) ratio even though pollen production in male flowers is only moderate.
High altitude species had larger flowers, higher pollen-ovule ratios, fewer ovules per female flower, and longer periods of anthesis. Gender differences were seen in the longer functionality of female flowers; the larger numbers of male flowers produced; and the average diameter at breast height (DBH) biased for one of the two sexes depending on the species investigated, with no clear trend in the size distributions of individuals of both sexes. Sex ratios departed significantly from unity both to male and female bias but usually were in favour of males. There were no general differences in the ratio of functional male to female flowers at the time of observation nor in the sizes of male and female flowers. The evolution of unisexual flowers in Siparuna can be explained as a result of the differential predation by larvae: unimportant in male flowers, destructive if occurring in female flowers.     

Mortality of the terrestrial adult and aquatic nymphal life stages of Baetis vernus and Baetis rhodani in the Breitenbach, Germany (Insecta: Ephemeroptera)

1. The mortality of Baetis vernus Curtis and Baetis rhodani Pictet during the terrestrial-aerial and aquatic life stages was studied at the Breitenbach near Schlitz, Hesse, Germany. The number of females emerging from the stream was recorded with emergence traps. To estimate mortality of females of both species during terrestrial life, numbers of emerging females were compared with numbers of females returning to the stream for oviposition, as shown by numbers of egg masses found in the stream. 2. Mortality of female B. vernus during their terrestrial life stage was 98.8%. It was 91.2 and 96.6%, respectively, during the first and second generations of B. rhodani. 3. To estimate the mortality of both sexes of B. rhodani during the aquatic life stage, the number of eggs laid by the first generation was compared with the number of adults emerging during the second generation. 4. Mortality during the aquatic phase (both sexes combined) of B. rhodani was 91.1%. 5. Mortality during the terrestrial life stages was at least as high, if not higher than during the aquatic stages. Evidently, there is a considerable export of organic material into the terrestrial environment around the stream. Mortality during terrestrial life may be an important regulator of population size.     

Coelenterate Neuropeptides: Structure, Action and Biosynthesis

Evolutionary "old" nervous systems such as those of coelenteratesare peptidergic: Using various radioimmunoassays we have nowisolated 13 novel neuropeptides from sea anemones and severalothers from hydrozoan polyps and medusae. These peptides areall structurally related and contain the C-terminal sequenceArg-X-NH₂ or Lys-X-NH₂, where X is Ala, Asn, Ile, Phe, Pro orTrp. Three neuropeptides have a novel N-terminal L-3-phenyllactylresidue, which protects against degradation by nonspecific aminopeptidases.The neuropeptides from sea anemones are produced by differentsets of neurones and have excitatory or inhibitory actions onisolated muscle preparations, suggesting that they are neurotransmittersor neuromodulators. We have also cloned the precursor proteinfor the sea-anemone neuropeptide Antho-RFamide (<Glu-Gly-Arg-Phe-NH₂).In Calliactis parasitica this precursor harbours 19 copies ofimmature Antho-RFamide (Gln-Gly-Arg-Phe-Gly) together with 7other, putative neuropeptide sequences. The precursor of Anthopleuraelegantissima contains 14 copies of Antho-RFamide and 19 other,putative neuropeptides. This shows that the biosynthetic machineryfor neuropeptides in coelenterates, the lowest animal grouphaving a nervous system, is already very efficient and similarto that of higher invertebrates, such as molluscs and insects,and vertebrates.     

A revision of the Oriental stonefly genus Phanoperla (Plecoptera: Perlidae)

The genus Phanoperla (=Dyaperla Banks, 1939) (Plecoptera: Perlidae: Perlini) is revised and generic diagnoses are provided for adults and larvae. Diagnostic and constitutive characters of the tribe Neoperlini are discussed, and Chinoperla Zwick, 1980, is shown to be the closest relative of Phanoperla. Many past misidentifications of Phanoperla species have been corrected by the use of characters recently recognized as important, namely the structure of the internal genitalia of male and female specimens and particularly the complex pattern of spines on the male penial sac made visible by eversion of this structure, and details of sculpturing of the egg chorion.
The following species of Phanoperla are recognized: amorpha sp.n.; anomala (Banks, 1939); bakeri (Banks, 1924); ceylonica Kawai, 1975; comuta sp.n.; flaveola (Klapálek, 1921), comb.n. ( =clarissa (Banks, 1913), syn.n.), (=Neoperla hageni Banks, 1920, syn.n.), (= N.consimilis Banks, 1924, syn.n.); guttata sp.n.; himalayana Zwick, 1977 (= siwalika Harper, 1977); limosa (Hagen, 1858); maculata sp.n.; maindroni (Navas, 1926), comb.n.; malayana sp.n.; minutissima (Enderlein, 1909); nana sp.n.; nervosa Banks, 1939; nuwara Kawai, 1975; omega sp.n.; pallipennis (Banks, 1938); parva sp.n.; pumilio (Klapálek, 1921), comb.n.; peniculus Kawai, 1969a; schmidi sp.n.; sertispina Jewett, 1975; srilanka sp.n.; sumatrae sp.n.; testacea (Hagen, 1858); wedda sp.n. P.claggi (Banks, 1938) is a nomen nudum.
All species are (re-)described and figured; all primary types have been examined. A key to species is provided. Most species can be assigned to one of seven species groups which are defined.
Phanoperla is endemic to the Oriental Region. Species groups are generally widespread, but individual species are in most cases known only from restricted areas.     

Analysis of Histones from the Endosymbiont Nucleus of a Binucleate Dinoflagellate1,2

Histones were prepared from chromatin of the eukaryotic (endosymbiont) nucleus of Peridinium balticum (Levander) Lemmermann. The amino acid composition of whole histone was rich in lysine and similar to that of Olisthodiscus luteus and Euglena gracilis. Electropheretic analysis of these proteins in acidic-urea disc gels revealed four major bands: one with a mobility slightly lower than that of calf thymus HI; and three others which comigrated with calf H2B, H2A, and H4, respectively. The low mobility band was soluble in 5% perchloric acid and was sensitive to FeCl₃ destaining. Electrophoresis in slab gels containing 0.1% SDS revealed five major components, with approximate molecular weights of 23,000, 20,000, 15,000, 13,000, and 11,000, respectively. The 15,000 and 11,000 dalton histones had mobilities identical to those of calf H3 and H4, respectively. The two highest molecular weight components were soluble in 5% perchloric acid. No bands were found to comigrate with calf H2A or H2B but a band was present that migrated to a position intermediate between calf H2A and H4 (13,000 dalton histone). Two-dimensional gels consisting of acidic-urea gels in the first dimension and SDS gels in the second dimension revealed that the 20,000 dalton component and the 13,000 dalton component are not resolved in the acidic-urea gel. As a working hypothesis, it is suggested that two of the five bands seen in SDS gels represent an H1-like doublet, and two are analagous to H3 and H4, respectively. The remaining histone may replace H2A and H2B.