The myosuppressins represent a subfamily of the insect FMRFamide-related peptides that share the common C-terminal heptapeptide sequence Asp-His-Val-Phe-Leu-Arg-Phe-NH,,' and have been identified in diverse insect species including the cockroach Leucophaea maderae, locusts Schistocerca gregaria and Locusta migratoria, the fleshfly Neobelleria bullata, and the fruitfly Drosophila melanogaster. Members of this family affect insect muscles, being potent inhibitors of cardiac and visceral muscle in addition to having effects on skeletal muscle and salivary glands. A related peptide, named ManducaFLRFamide, was isolated from the hawkmoth Manduca sexta and demonstrates myostimulatory activity on dorsal longitudinal flight muscles.'The related sulfakinin insect peptide family shares the C-terminal octapeptide sequence Xaa-Asp-Tyr(S03H)-G1y-His-Met-Arg-Phe-NH2 (Xaa = Glu or Asp) that terminates in HMRFamide, rather than the FLRFamide of the myosuppressins. The sulfakinins also share sequence similarities with the vertebrate gastrin/ cholecystokinin (CCK) hormone family with a C-terminal gastrin octapeptide sequence of Glu-Ala-Tyr(S0,H)-G1y-Trp-Met-Arg-Phe-NH2. Unlike the myosuppressins, the sulfakinins stimulate contractions of the isolated cockroach hindgut, the original bioassay used to isolate t h e~n .~,~ In this study, we report that members of the myosuppressin and sulfakinin Corresponding author. 335 336 ANNALS NEW YORK ACADEMY OF SCIENCES 35 -7

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[1] Remotely sensed data are combined with shipboard measurements to investigate biogeochemical changes caused by a moderate tropical cyclone in the central Arabian Sea in December 1998. The sea surface temperature decreased by $4°C, whereas surface nitrate and chlorophyll concentrations increased by >5 mM and up to 4 mg m À3 , respectively, over a large area affected by the cyclone. Nutrient enrichment in the surface layer of the cyclone-affected zone is estimated to have supported a new production of $4.2 Tg C, approximately 5% of the annual organic carbon export to the deep sea (beyond the continental margin) for the entire Arabian Sea. Entrainment of nitrous oxide from the thermocline led to more than doubling of its concentration in the mixed layer. The cyclone also resulted in an increase in nitrous oxide inventory within the oxygen minimum zone. Our results imply that, should there be an increase in the frequency and intensity of tropical cyclones as a result of global warming, as projected in some recent reports, carbon production and respiration, and redox processes within the oxygen minimum zones, such as the production of nitrous oxide through nitrification/ denitrification, and of molecular nitrogen through denitrification/anaerobic ammonium oxidation, may be significantly impacted.

Abstract. Phytoplankton and bacterial pigment compositions were determined by high performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) in two freshwater reservoirs (Tillari Dam and Selaulim Dam), which are located at the foothills of the Western Ghats in India. These reservoirs experience anoxia in the hypolimnion during summer. Water samples were collected from both reservoirs during anoxic periods while one of them (Tillari Reservoir) was also sampled in winter, when convective mixing results in well-oxygenated conditions throughout the water column. During the period of anoxia (summer), bacteriochlorophyll (BChl) e isomers and isorenieratene, characteristic of brown sulfur bacteria, were dominant in the anoxic (sulfidic) layer of the Tillari Reservoir under low light intensities. The winter observations showed the dominance of small cells of Chlorophyll b-containing green algae and cyanobacteria, with minor presence of fucoxanthin-containing diatoms and peridinin-containing dinoflagellates. Using total BChl e concentration observed in June, the standing stock of brown sulfur bacteria carbon in the anoxic compartment of Tillari Reservoir was estimated to be 2.27 gC m−2, which is much higher than the similar estimate for carbon derived from oxygenic photosynthesis (0.82 gC m−2. The Selaulim Reservoir also displayed similar characteristics with the presence of BChl e isomers and isorenieratene in the anoxic hypolimnion during summer. Although sulfidic conditions prevailed in the water column below the thermocline, the occurrence of photo-autotrophic bacteria was restricted only to mid-depths (maximal concentration of BChl e isomers was detected at 0.2% of the surface incident light). This shows that the vertical distribution of photo-autotrophic sulfur bacteria is primarily controlled by light penetration in the water column where the presence of H2S provides a suitable biogeochemical environment for them to flourish.