Checklist of Macroalgae in Waisai Coast, Raja Ampat

Macroalgae are very abundant organisms in Indonesian coastal zone. They comprise 8.6% of the total marine organisms.The aim of the research was to identify macroalgae in Waisai Coast Raja Ampat. The results showed that 38 macroalgae were found in Waisai Coast Raja Ampat but only 29 species of macroalgae can be identified. Macroalgae found in Waisai Coast Raja Ampat are green algae, red algae and brown algae. Green algae found and identified are <em>Caulerpa macra </em>(Weber-van Bosse) Draisma &amp; Prud’homme, <em>Caulerpa racemosa var. macrophysa </em>(Sonder wx Kutzing) W.R.Taylor, <em> Caulerpa sertularoides</em> (S. Gmelin) Howe f. brevipes (J. Agardh Svedilus), <em>Caulerpa cupressoides</em> (Vahl) C. Agardh, <em>Halimeda discoidea</em> Decaisne, <em>Halimeda Opuntia</em> (Linnaeus) J.V. Lamoroux, <em>Halimeda tuna</em> (J. Ellis &amp; Solander) J.V. Lamoroux, <em>Halimeda cylindraceae</em> Decaisne, <em>Halimeda macroloba</em> Decaisne, <em>Avrainvillea erecta</em> (Berkeley) A. Gepp &amp; E.S. Gepp, <em>Codium geppiorum</em> O.C.Schmidt, <em>Boergesenia forbesii</em> (Hardvey) Feldmann, <em>Valonia ventricosa</em> J. Agardh, <em>Dictyosphaeria cavernosa</em> (Forsskål) Børgesen, <em>Chaetomorpha spiralis</em>Okamura, <em>Anadyomene wrightii</em> Harvey ex. J. E. Gray, <em>Neomeris annulata</em> Dickie. Red algae species found and successfully identified are<em>Acanthophora spicifera</em> (M. Vahl) Børgesen, <em>Laurencia papilosa</em> (C. Agardh) Greville, <em>Gracilaria salicornia</em> (C. Agardh) E.Y. Dawson, <em>Amphiora fragilissima</em> (Linnaeus) J.V. Lamoroux, <em>Hypnea pannosa</em> J. Agardh. Brown algae species found and identified are <em>Hormophysa cuneiformis</em> (J.F. Gmelin) P.C. Silva, <em>Sargassum aquifolium</em> (Turner) C. Agardh, <em>Sargassum polycystum</em> C. Agardh, <em>Turbinaria ornata</em> (Turner) J. Agardh, <em>Padina australis</em> Hauck, <em>Canistrocarpus cervicornis </em>(Kutzing) De Paula &amp; De Clerck<em> Hydroclathrus clatratus</em> (C. Agardh ) M. Howe. The only species found in Indonesia is <em>Sargassum aquifolium.</em>

Swelling of Valonia cellulose microfibrils in amine oxide systems

Cellulose microfibrils from Valonia ventricosa cell-wall fragments were immersed into molten N-methylmorpholine-N-oxide monohydrate (NMMO·H2O), stabilized with n-propyl gallate and kept at 80 °C. The resulting ultrastructural modifications, which were followed by transmission electron microscopy and electron diffraction analysis, showed that within minutes the solvent slowly penetrated inside the crystalline microfibrils and progressed as a wedge in between the cellulose chains without cutting them. Prior to dissolution, a longitudinal subfibrillation of the initial microfibrils occurred, leading to the observation of highly swollen microfibrils, which could reach diameters up to three times larger than those of the initial samples. This mode of swelling is compared with those occurring in other systems, where the intracrystalline swelling of cellulose has been described at the ultrastructural level.Key words: cellulose swelling, Valonia cellulose, N-methylmorpholine-N-oxide.

Efficiency of using emerald crabs Mithraculus sculptus to control bubble alga Ventricaria ventricosa (syn. Valonia ventricosa) in aquaria habitats

Ornamental crabs of the genus Mithraculus (Decapoda: Brachyura: Majidae) are utilized in reef aquaria to control nuisance algae, particularly bubble algae. Although Mithraculus have modified, spooned-shaped chelae to feed on both fleshy and filamentous algae, they may consume alternative foods offered in a reef aquarium. The objective of this study was to determine the efficiency of using Mithraculus sculptus to control the bubble alga Ventricaria ventricosa (Siphonocladales–Cladophorales complex, Chlorophyta) in the presence of alternative foods (commercial pellets and frozen mysids) commonly utilized in reef aquaria. Results indicated that medium and large sized crabs consumed more bubble algae than smaller conspecifics. Although, M. sculptus first chose alternative foods to bubble alga (77% and 69% of the time chose pellets and frozen mysids, respectively), algal consumption only decreased significantly if, besides algae, pellets were provided; when only algae were provided, algal consumption was similar to when they were provided with mysids. The prey choice model was used as a conceptual framework to study the mechanisms underlying active selection; food energy content and handling time were measured and food profitability was calculated. Handling time decreased with increasing crab size. Pellets presented a higher profitability than algae but mysids and algae presented similar profitability; this seems to be in agreement with the observed reduced algal consumption when pellets made part of the diet. Mithraculus sculptus feeding behaviour on V. ventricosa recorded with digital high-speed video (DHSV) suggests that as the crab tears the algal cell apart, the cell liquid that contains juvenile cytoplasmatic spheres is released into the water; this behaviour might contribute to algal dispersal and consequently algal infestation. These results seem to indicate that M. sculptus might not be such an efficient bio-controller of the pest V. ventricosa as previously thought, particularly when pellets are used as food; however, its bio-control efficiency might be improved if, mysids are used as food.

On the cross-sectional shape of the cellulose crystallites in the tunicate Halocynthia papillosa

The only form of cellulose which could unequivocally be ascribed to the animal kingdom is the tunicin that occurs in the tests of the tunicates. Recently, high-resolution solid-state l3C NMR revealed that tunicin belongs to the Iβ form of cellulose as opposed to the Iα form found in Valonia and bacterial celluloses. The high perfection of the tunicin crystallites led us to study its crosssectional shape and to compare it with the shape of those in Valonia ventricosa (V.v.), the goal being to relate the cross-section of cellulose crystallites with the two allomorphs Iα and Iβ.In the present work the source of tunicin was the test of the ascidian Halocvnthia papillosa (H.p.). Diffraction contrast imaging in the bright field mode was applied on ultrathin sections of the V.v. cell wall and H.p. test with cellulose crystallites perpendicular to the plane of the sections. The electron microscope, a Philips 400T, was operated at 120 kV in a low intensity beam condition.