1,735 research outputs found
Effect of lignin type on extent and rate of neutral detergent fibre digestion and potential energy yield
No full textAmphilectus strepsichelifer Van Soest, Beglinger, Vooged 2012, sp. nov.
No full text<i>Amphilectus strepsichelifer</i> sp. nov. <p>Fig. 4</p> Etymology <p> The name is a combination of <i>strepsis</i> (L.) = twisted, and <i>chelifer</i> (L.) = bearing chelae, reflecting the twisted condition of the chelae.</p> Material examined <p> <b>Holotype</b></p> <p>ZMA Por. 07564, Cape Verde Islands, W of São Vicente, Canal de São Vicente, depth 348-354 m, coll. R. W.M. Van Soest, CANCAP 7 Expedition stat. 172/03, 16.8833°N 25.1167°W, rectangular dredge, 7 Sep. 1986.</p> Description <p>Pedunculate sponge (Fig. 4A), with long thin smooth stalk and abruptly attached small ovate main body. Main body flattened, but solid (not hollow). Upper surface somewhat rectangular, caused by preparation damage. Surface irregular, shaggy. Colour light brown alive, grey in alcohol. Size of main body 12 x 6 mm, stalk 35 mm long, 1.2 mm thick.</p> <p>SKELETON. Of main body plumose, rather than plumoreticulate, with diffuse spicule bundles directed at right angles to the surface (Fig. 4B), where they form loose brushes. Connecting spicules few and arranged irregularly. Chelae in loose groups in a subectosomal layer at the base of the surface brushes (Fig. 4C). Few chelae in the interior.</p> <p>SPICULES. (Fig. 4 D-E) Styles, palmate isochelae.</p> <p> STYLES. (Fig. 4D, D 1) Thin, slightly curved, 396- <i>430.5</i> -462 x 3- <i>4.6</i> - 7 µm.</p> <p> PALMATE ISOCHELAE. (Fig. 4E) Predominantly with ‘twisted’ shaft, causing the alae of opposite ends to face different angles, a minority of the chelae appearing ‘normal’ but these are of the same size as the twisted ones, and upon closer examination appear to be slightly twisted as well, 32- <i>33.7</i> - 36 µm.</p> Distribution and ecology <p>Known only from the type locality between the islands of São Vicente and Santo Antão, Cape Verde Islands (Fig. 1, loc. 4), hard bottom, at depths below 300 m.</p> Remarks <p> The species is assigned to <i>Amphilectus</i> on the same basis as <i>A. utriculus</i> sp. nov. The species stands out among stalked <i>Amphilectus</i> species (see above in the remarks on <i>A. utriculus</i> sp. nov.) by the peculiar twisted condition of the palmate isochelae. Additionally the thin stalk carrying the main body without a clear intermediate zone is characteristic and not found in the other North Atlantic <i>Amphilectus</i> species.</p>Published as part of <i>Van Soest, Rob W. M., Beglinger, Elly J. & de Voogd, Nicole J., 2012, Sponges of the family Esperiopsidae (Demospongiae, Poecilosclerida) from Northwest Africa, with the descriptions of four new species, pp. 1-21 in European Journal of Taxonomy 18</i> on pages 7-9, DOI: 10.5852/ejt.2012.18, <a href="http://zenodo.org/record/3857876">http://zenodo.org/record/3857876</a>
The coevolution of renewable resources and institutions - implications for policy design
No full text This PhD thesis studies how natural renewable resources and institutions governing those resources mutually influence each other. Theoretical models are developed in which members of a small community have joint access to a common pool resource. We analyze under which circumstances social norms of cooperation evolve that effectively regulate resource exploitation, but also when those social norms break down, identifying obstacles for community governance. Furthermore, in the light of biological and social complexity this thesis analyzes how governmental policy should be designed if self-governance is not sufficient to protect the resource stock. The insights obtained are applied to the case of Arcto-Norwegian cod. An optimal management plan is developed that can be adapted to several policy objectives concerning the utilization of the fleet. In addition, management advice is given for the case that harvesting may trigger an evolutionary response of the fish stock. </p
The feeding and nutrition of small ruminants: application of the Cornell Discount System to the feeding of dairy goats and sheep
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Pericharax orientalis Van Soest & De Voogd 2015
No full textPericharax orientalis Van Soest & De Voogd, 2015 Figs 51a–h Pericharax heteroraphis; sensu Dendy 1913: 13 (not: Pericharax carteri var. heteroraphis Poléjaeff, 1883: 66). Pericharax orientalis Van Soest & De Voogd, 2015: 57, figs 41a–e, 42a–e. Material examined. RMNH Por. 10157, Maldives, Faafu Atoll, Wallstreet, 3.119°N 72.979556°E, depth 12 m, scuba, coll. N.J. de Voogd, field nr. MAD10/MAS118, 20 February 2015; ZMA Por. 17996, Mauritius, 20.0304°S 57.5364°E, depth 7–28 m, scuba, coll. P. Daniel Marie, field nr. MO4SP5TB, 2014; ZMA Por. 18308, Mauritius, 20.0378°S 57.5361°E, depth 10–20 m, scuba, coll. P. Daniel Marie, field nr. 5, December 2014; ZMA Por. 21792, Mauritius, depth 10–20 m, scuba, coll. P. Daniel Marie, field nr. VI sp.17, December 2010. Description. Since this species was treated extensively recently (see Van Soest & De Voogd, 2015), we provide here only a short description. Large, yellow-green, upright or volcanoe-shaped sponges (Fig. 51a), with faintly ridged or shallowly grooved sides and prominent wide central vent or oscule. Occasionally two or more individuals are attached forming a small group. Sizes up to 10 cm or more in height, 10 cm or more in diameter. Surface may be covered in tiny tubes of syllid worms. In preservation, specimens become red-brown (Fig. 51b). Consistency hard, rough to the touch. Aquiferous system. Leuconoid. Skeleton. Cortical region with a thin layer of small sagittal triactines forming rounded subdermal spaces, carried by tangentially arranged subcortical giant triactines. Choanosomal skeleton built predominantly by small triactines supporting the leuconoid canal system. The atrial walls are formed predominantly by tetractines with their apical actines protruding into the atrial cavity (Fig. 51c). Spicules. (Figs 51d–h) Giant triactines, small cortical triactines, small choanosomal triactines, atrial tetractines. Giant triactines (Fig. 51d), equiradiate, equiangular, 396– 1386 –2310 x 28– 124.3 –222 µm. Cortical triactines (Fig. 51e), irregular, slightly sagittal, with all three actines slightly different and somewhat wavy, 54– 88 –119 x 6 – 8.1 –11 µm. Small triactines (Fig. 51f), regular, equiradiate, equiangular, 126– 181 –228 x 12 – 15.9 –23 µm. Tetractines (Figs 51g –h), with basal radiate system equiradiate, equiangular, actines 106– 156 –192 x 7 – 11.3 –17 µm, apical actines (Fig. 51h) thin, mostly wavy or curved, but may be straight, 25– 67 –108 x 4 – 6.4 –10 µm. Distribution and ecology. Maldives, Mauritius, elsewhere widely distributed in the Indo-West Pacific tropical region, on reefs down to 20 m or deeper. Remarks. Pericharax peziza Dendy, 1913 is a small cup-shaped sponge, pale yellow in alcohol, which has not been found again after its original description from Cargados Carajos. Its skeletal architecture and spiculation is similar to P. orientalis. We obtained sequences of the holotype of Pericharax orientalis from Indonesia (RMNH Por. 5259) and of the above described RMNH Por 10157 from the Maldives and in our phylogenetic analysis (Fig. 2C) both ended up in the same clade at moderate bootstrap value. Recently, Leocorny et al. (2017) described several new Pericharax species from Western Australia, P. vallii Leocorny et al., 2017, and P.crypta Leocorny et al., 2017. These species clearly differ from the present specimens in aspects of habitus and spicule sizes. Leocorny et al. (2017) found that Leucetta and Pericharax could not be retrieved as monophyletic, and this is confirmed in our Fig. 2C.Published as part of Van, Rob W. M. & De, Nicole J., 2018, Calcareous sponges of the Western Indian Ocean and Red Sea, pp. 1-160 in Zootaxa 4426 (1) on pages 87-89, DOI: 10.11646/zootaxa.4426.1.1, http://zenodo.org/record/127123
Placospongia ruetzleri van Soest 2017
No full text<i>Placospongia ruetzleri</i> Van Soest, 2017 <p>(Fig. 3; Tab. 2)</p> <p> <i>Placospongia ruetzleri</i> Van Soest, 2017: 173, figs 108 a–g.</p> <p> <b>Material examined.</b> UFPE POR 1462, Cabo de Santo Agostinho, Praia Enseada dos corais, 8º19’0.34’’S – 34º56’51.92’’W, Pernambuco State, Brazil, intertidal zone, June 3rd, 2011, coll. Pinheiro, U.</p> <p>UFBA 769, Itacimirim, Camaçari, 12°36’40.28”S – 38°02’26.06”W, Bahia State, Brazil, 1982, coll. Peixinho, S.; UFBA 2991, Baía de Camamu, Ilha da Pedra Furada, 13º53’35’’S – 38º59’58’’W, Bahia State, Brazil, intertidal zone, May, 2009, coll. Fernandez, J. & Santos, G.; UFBA 1571, Arembepe, Camaçari, - 12º47’00’’S – 38º11’00’’W, Bahia State, Brazil, intertidal zone, 0–1 m deep, January 12th, 1997, coll. Peixinho, S.; UFBA 633, Porto da Barra, Salvador, 13º00’06’’S – 38º32’00’’W, Bahia State, Brazil, <10 m deep, September 30, 1984, coll. Nunes, M.</p> <p> <b>Description.</b> Encrusting sponges (Based on UFBA 769 measurements: Fragment 1: 36.51 mm length x 14.83 mm width, 5.10 mm thickness, fragment 2: 28.56 mm length x 22.88 mm width, 4.10 mm thickness; fragment 3: 25.99 mm length x 19.71 mm width, 3.53 mm thickness), covered by smooth and rigid cortical plates separated by contractible grooves (Fig. 3A). Brown color in life. Firm consistency, non-compressible sponges. Oscules not observed.</p> <p> <b>Skeleton.</b> Cortex with densely packed selenasters. Choanosome with bundles of tylostyles disposed outwards, arising from a basal or a central axis of selenasters, providing support to cortex. Selenasters in different developmental stages, acanthomicrorhabds, and spirasters dispersed in the choanosome (Fig. 3B).</p> <p> <b>Spicules. Megascleres.</b> Tylostyles in two size categories, straight with spherical tyles, hastate and blunt (Fig. 3E) or mucronate (Fig. 3H) ends in both. Tylostyles I (Fig. 3C), larger (530–912.3–1150µm/12.5–16.5–20µm); tylostyles II (Fig. 3F), smaller (190–300.5–540µm/7.5–11.4–15µm). <b>Microscleres</b>. Bean-shaped to oval or sometimes spherical selenasters (Fig. 3I) (47–67.3–77µm/33–55.5–70µm). Irregular spirasters (Fig. 3J,K), with twisted shaft presenting one or two spiral turns, rays bifurcate or with tuft concentrated in the ends (8–13 rays), with shorter and longer secondary rays and spines. Microspined rays disposed sparsely, exclusively at the convex side (Fig. 3J) or densely in throughout the spicule (Fig. 3K), with two terminal clusters and rays in central region (13–19–23µm/3– 3.7–6µm). Acanthomicrorhabds abundant (Fig. 3L), with straight or slightly sinuous shafts (6–9.7–13µm/2–2.9– 4µm).</p> <p> <b>Substratum, depth range and ecology.</b> Encrusting rocky substratum in the intertidal zone, or subtidal to <10 m deep.</p> <p> <b>Distribution. Southwest Atlantic.</b> Originally described from Suriname and the Guyana Shelf (Van Soest, 2017). In the present study, it is recorded for the first time from Brazil: Pernambuco State (Cabo de Santo Agostinho, Praia Enseada dos Corais), Bahia State (Camaçari: Northern coast, Todos os Santos Bay: Salvador, Praia Farol da Barra: central region and Baía de Camamu: Ilha da Pedra Furada).</p> <p> <b>Remarks.</b> <i>P. ruetzleri</i> was originally described from the Guyana shelf, in French Guyana and was reported from Florida, Jamaica, Grenada, Colombia and NE Brazil (van Soest, 2017). However, this Brazilian record was considered doubtful due to insufficient information (van Soest, 2017). In the present study, we confirm its occurrence to northeastern Brazil.</p> <p> In Suriname, this species was found in sandy bottom and in murky waters with muddy bottom at 25–34 m depths, the occurrence of sponges in this type of substrate is considered rare (van Soest 2017). Brazilian species of <i>P. ruetzleri</i> are recorded for intertidal reef environments, composed by sandy sediments at 0–10 m depths.</p> <p>Although the specimens from Brazil and from Suriname come from environments with distinct features (high turbid waters, and muddy bottoms in Suriname), the samples of these two regions contain the same spicular categories, with presence of unique spirasters with spines disposed exclusively at the convex side of the microsclere. In the Brazilian specimens, here described, the spirasters can be sparsely spined or, more rarely, densely spined.</p>Published as part of <i>Mácola, Rosa & Menegola, Carla, 2021, A new species of Placospongia Gray, 1867 (Porifera, Demospongiae, Placospongiidae) and new record of P. ruetzleri van Soest, 2017 from Northeast, Brazil, pp. 12-22 in Zootaxa 5072 (1)</i> on pages 16-18, DOI: 10.11646/zootaxa.5072.1.2, <a href="http://zenodo.org/record/5728925">http://zenodo.org/record/5728925</a>
Estimation of the indirect translog demand system with binding non-negativity constraints
No full textConsumption Function;econometrics
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