You cannot conserve a species that has not been found: The case of the marine sponge Axinella polypoides in Liguria,Italy

1. Detailed knowledge about the distribution of species in need of protection is required for the management of Marine Protected Areas, a major tool to reduce marine biodiversity loss. Such knowledge is deficient for most marine invertebrates.
2. Axinella polypoides is a marine sponge included on the list of protected species by the Barcelona Convention (1976) and the Bern Convention (1987). This large and erect species has an important ecological role in habitat forming and benthic–pelagic coupling.
3. Bathymetrical, geographical and ecological data over the last 60 years were collated from publications and reports, together with new surveys to assess the distribution and protection status in Liguria of A. polypoides. It identified a more widespread distribution than previously thought, which points at a general need for dedicated investigations on the occurrence of species that require protection.
4. Bathymetrical distribution was trimodal, with peaks corresponding to different geomorphological settings: coastal cliff bases (around 38 m depth), inner shelf shoals (52 m) and rocks amidst coarse sediment on the outer shelf (79 m). Density was significantly greater at the shallowest depths. The species was mostly found in the coralligenous biocoenosis, in association with other characteristic species or forming a monospecific facies.
5. On (sub)vertical cliffs, A. polypoides often exhibited an unusual cane shape, rather than the typical bushy morphology, thus causing confusion with the congeneric A. cannabina, a more southern species. Records of the latter in the Ligurian Sea therefore need confirmation.
6. Only a minority (22.6%) of A. polypoides records were in Marine Protected Areas, the remainder being located in areas with no current environmental protection plans in place. While the occurrence of this species in MPAs remained stable over the decades, the only quantitative historical data available indicated that populations in non-protected areas were declining owing to anthropogenic impacts (fishing and anchoring).

     

Qualitative modelling of the kelp forest of Lessonia nigrescens Bory (Laminariales: Phaeophyta) in eulittoral marine ecosystems of the south–east Pacific: an approach to management plan assessment

This contribution aims at the assessment of the sustainability of a management plan for Lessonia nigrescens in Chilean coastal ecosystems, specially when the harvest pressure could be increased due to that this macroalgae is considered as a food source for the abalon (Haliotis discus hannoi) farming along the Chilean coast. Three qualitative conceptual models were developed and compared; the first and second ones assuming homogeneous and heterogeneous environmental conditions, respectively, and the third expanded one considering eco-social components under the assumption of environmental heterogeneity. For all these models, the factors described by Vásquez [Bot. Mar. 38 (1995) 251] were included in the management plan for the harvesting of brown macroalgae. Based on Levins's Loop Analysis, the system will have a just weakly unstable moving equilibrium if the harvesting activities do not negatively affect the macrophyta's reproduction and recruitment processes. Therefore, coincidence of reproduction and/or recruitment with harvesting must be avoided in a putative management plan. Regarding the qualitative predictions of the system's behaviour after negatively affecting reproduction and recruitment, only an ecological model assuming a heterogeneous environment shows realistic responses in comparison to experimental studies on the same species. This contribution is the first approach considering the dynamical behaviour of L. nigrescens and its surroundings. Nevertheless, further models, based on the same modelling theory, may integrate more variables from social and economical fields in order to improve the scope of this complex system. Further comparative studies should focus on the assessment of the significance of the structural functions of L. nigrescens and other macroalgae for the conservation of this benthic system.     

Global-scale genetic structure of a cosmopolitan cold-water coral species

• 1. When considering widely distributed marine organisms with low dispersal capabilities, there is often an implication that the distribution of cosmopolitan species is an artefact of taxonomy, constrained by the absence of characters for delimiting either sibling or cryptic species. Few studies have assessed the relationship among populations across the global range of the species' distribution, and the presence of oceanographic barriers that might influence gene flow among populations are underestimated.
• 2. In this study, evolutionary and ecological drivers of connectivity patterns have been inferred among populations of the cold-water coral Desmophyllum dianthus, a common and widespread solitary scleractinian species, whose reproduction strategy and larval dispersal are still poorly unknown.
• 3. The genetic structure of D. dianthus was explored using 30 microsatellites in 347 specimens from 13 localities distributed in the Mediterranean Sea and Atlantic and Pacific Oceans.
• 4. Results clearly reveal genetically differentiated populations in the Northern and Southern Hemispheres (F_ST = 0.16, F_SC = 0.01, F_CT = 0.15, P-values highly significant), and Chilean and New Zealand populations with independent genetic profiles.
• 5. Marine connectivity patterns at different spatial scales are discussed to characterize larval dispersal and gene flow through the Northern and Southern Hemispheres.

     

Manufacture and characterization of pasta made with wheat flour rendered gluten-free using fungal proteases and selected sourdough lactic acid bacteria

Wheat flour, which was rendered gluten-free by sourdough lactic acid bacteria fermentation and fungal proteases, was used for manufacturing experimental gluten-free pasta (E-GFp), according to a traditional process with low temperature drying cycle. Chemical, technological, structural, nutritional and sensory features were characterized and compared with those of commercial gluten-free (C-GFp) and durum wheat pasta (C-DWp). As shown through immunological analyses, the residual concentration of gluten of the hydrolyzed wheat flour was below 10 ppm. E-GFp showed rapid water uptake and shorter optimal cooking time compared to the other pastas. Despite the absence of the gluten network, the supplementation with pre-gelatinized rice flour allowed structural properties of E-GFp, which were comparable to those of C-GFp. The in vitro protein digestibility of E-GFp resulted the highest. Probably due to proteolysis during sourdough fermentation; chemical scores, essential amino acid profile, biological value and nutritional index of E-GFp were higher than those of C-DWp. The hydrolysis index (HI) of E-GFp was ca. 30% lower than that found for C-GFp. As shown by sensory analysis, the characteristic of E-GFp were acceptable. The manufacture of E-GFp should be promising to expand the choice of gluten-free foods, which combine sensory and nutritional properties.     

Local and remote physical processes driving variability of the planktonic system in the Juan Fernández Archipelago: A multidisciplinary framework providing conservation insights

1. The Juan Fernandez Ridge, a vulnerable marine ecosystem located far off the coast of central Chile and formed by several seamounts, guyots and three islands (Robinson Crusoe, Santa Clara and Alejandro Selkirk), has recently been declared a Coastal Marine Protected Area of Multiple Uses with several National Parks embedded in it.
2. Recent studies have highlighted the influence of remote and local oceanographic structures on the hydrographic dynamics of this ridge. However, there is still a gap in understanding how they affect the structure and dynamics of the surrounding insular planktonic communities.
3. A hydroacoustic and oceanographic survey was conducted during the austral spring (October 2016), including hydrographic and zooplankton sampling around Robinson Crusoe Island. Oceanographic features were identified and tracked using satellite data (chlorophyll-a (Chl-a) and sea surface temperature) and modelling results.
4. Two events of Chl-a increase relative to a threshold (>0.45 mg m⁻³) were forced by different physical processes, both affecting the western side of Robinson Crusoe Island. In event A during the cruise period, Chl-a subsurface maxima were associated with the arrival of a coastal meander originating on the continental shelf off Chile (remote process); the zooplankton was dominated by copepods and salps, with an evident coastal–oceanic gradient. In event B, Chl-a maxima were linked to a local upwelling forced by the intensification of a localized SSW wind. No influence of remote eddies or local Von Kármán vortices on Chl-a distribution was observed.
5. These findings highlight the influence of remote and local physical processes on the structure of planktonic communities around Robinson Crusoe Island. Understanding the variability of these mechanisms and their effects at the base of the pelagic food web is critical in adopting an ecosystem-level approach.

     

Studies on the Nutrition of Spotted Sand Bass Paralabrax maculatofasciatus: Effect of the Dietary Protein Level on Growth and Protein Utilization in Juveniles Fed Semipurified Diets

Two feeding trials were conducted to determine the digestibility of a casein-based semi-purified diet and the effects of different protein levels on growth and protein use of spotted sand bass Paralabrax maculatofasciatus juveniles. For trial I, a semipurified diet with vitamin-free casein as the sole source of protein was fed three times a day to apparent satiation, for a period of 20 d. Feces were collected by siphoning each tank. The digestibility of the experimental diet was high: 97% for protein, 89% for lipids, and 84% for gross energy, whereas that of organic matter was 78%. For trial II, seven diets were formulated using vitamin-free casein at graded levels (25, 30, 35, 40, 45, 50, and 55% protein). Triplicate tanks for each dietary treatment were stocked with fish and fed by hand three times a day to apparent satiation for 6 wk. Perfomance of fish fed the different diets was evaluated for survival, percent weight gain, specific growth rate, feed conversion ratio, and protein efficiency ratio. Survival was 100% for all treatments. Growth of spotted sand bass juveniles increased as the dietary protein increased, but no evidence of reaching a plateau was found. The daily feed intake values showed an inverse relation to the protein content of the diets. The feed conversion ratio did not differ among diets containing 40% protein or greater. The results indicate that spotted sand bass juveniles with 2.5-g mean weight need at least 55% dietary protein for best growth when casein is the sole protein source. However, in terms of feed conversion ratio, the requirement apparently could be lower.     

Resumption of ovarian activity in zebu cows (Bos Indicus) in the humid tropics: influence of body condition and levels of certain blood components related to nutrition

Summary This study investigated the relationship between resumption of ovarian activity and body condition in a herd of 20 zebu cows in the humid tropics. Blood chemistry profiles to monitor nutritional status were also evaluated. Plasma progesterone was used to determine ovarian activity. During the study, which lasted 18 weekspost partum, 7 of the animals resumed ovarian activity while 13 remained in the anoestrous stage. The beginning of the first luteal phase was registered on day 87±19 (range 60 to 106). The animals which resumed cyclicity were in significantly better body condition and had significantly higher mean body weight than anoestrous cows. In the group which resumed ovarian activity, calcium levels decreased significantly from 3 weeks before until the first rise of progesterone in the first normal cycle. The study was divided into 2 periods corresponding to weeks 0 to 8 (I) and 9 to 18 (II) based on the finding that until week 8 all animals were reproductively inactive. During period I there were no significant differences between the groups in blood concentrations of albumin, glucose, urea, cholesterol, calcium and phosphorus. During period II albumin was significantly higher and urea significantly lower in the cows resuming ovarian activity. The results suggest that cows able to maintain their body condition from calving through the earlypost-partum period will have shorter intervals to firstpost-partum oestrus than cows which have lost body weight. The lower urea and higher albumin levels in the cyclic animals probably reflected a better feed efficiency—the demands of lactation were compensated by an altered nitrogen metabolism.

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Reinicio De La Actividad Ovarica En Vacas Zebu (Bos Indicus) En El Tropico Humedo: Influencia De La Condicion Corporal Y De Los Niveles Plasmaticos De Algunos Compuestos Relacionados Con La Nutricion

Resumen Este estudio investigó la relación entre el reinicio de la actividad ovárica y la condición corporal en un rebaño de 20 vacas zebú en el trópico húmedo. Se realizaron también análisis de sangre para monitorizar el estado nutricional de los animales. Se utilizaron los niveles plasmáticos de progesterona para determinar actividad ovárica. Durante el estudio, que duró las primeras 18 semanas postparto, 7 animales reiniciaron la actividad ovárica mientras que los 13 restantes permanecieron en anoestro. El inicio de la primera fase luteínica tuvo lugar el día 87±19 postparto (rango 16–106). Los animales que reiniciaron la actividad ovárica tenían una condición corporal significativamente mejor y un peso significativamente más alto que los animales que se mantuvieron en anoestro. En el grupo de animales que reinició la actividad ovárica, la concentración plasmática de calcio disminuyó significativamente durante las tres últimas semanas antes del aumento en la concentración de progesterona correspondiente al primer ciclo ovárico. Debido a que hasta la octava semana después del parto todos los animales estuvieron en anoestro, el estudio se dividió en dos períodos: período I (semanas 1 a 8) y período II (semanas 9 a 18). Durante el período I no se encontraron diferencias significativas entre los dos grupos de animales en las concentraciones plasmáticas de albúmina, glucosa, urea, colesterol, calcio ni fósforo. Durante el período II la concentración de albúmina fue significativamente más alta en el grupo de animales que reiniciaron la actividad ovárica, mientras que la concetración de urea fue significativamente mayor en los animales que permanecieron en anoestro. Los resultados sugieren que las vacas que son capaces de mantener su condición corporal durante las primeras semanas postparto tienen intervalos parto-estro más cortos que las vacas que han perdido condición corporal. El hecho de que los animales que reiniciaron antes su actividad ovárica tuvieran una concentración plasmática de albúmina superior y una concentración de urea inferior que los que permanecieron en anoestro probablemente refleja una mayor eficiencia en la utilización del alimento en los animales que reiniciaron la actividad ovárica. Es decir, las demanadas energéticas de la lactación fueron compensadas mediante un cambio en el metabolismo del nitrógeno.

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Reprise De l'Activite Ovarienne Chez Des Femelles Zebus (Bos Indicus) Dans Les Pays Tropicaux Humides: Influence De l'Etat De Sante Et Des Teneurs De Certains Composants Sanguins Lies A l'Alimentation

Résumé Cette étude examina la relation centre la reprise de l'activité ovarienne et l'état de santé d'un groupe de 20 femelles zébus des pays tropicaux humides. Les profiles chimiques du sang furent aussi analysés pour contrôler l'état nutritionnel. La teneur en progestérone du plasma fut utilisée pour déterminer l'activité ovarienne. Pendant l'étude, qui dura 18 semaines après le vêlage, sept animaux reprirent une activité ovarienne alors que treize restèrent à un stade sans oestrus. Le début de la première phase lutéale fut enregistré au jour 87±19 (écart 60–106). Les animaux qui reprirent des cycles furent de façon significative en meilleure condition physique et eurent un poids moyen significativement superieur aux femelles sans oestrus. Dans le groupe qui reprit une activité ovarienne, les teneurs en calcium diminuèrent de façon significative trois semaines avant la première montée de progestérone du premier cycle normalisé. L'étude fut divisée en deux périodes correspondant aux semaines 0–8 (phase I) et 9–18 (phase II) se basant sur le fait que les animaux furent tous inactifs du point de vue reproductif jusqu'a la huitième semaine. Pendant la phase I, il n'y eut pas de différences significatives entre les groupes pour les concentrations sanguines en albumine, glucose, urée, cholestérol, calcium et phosphore. Pendant la phase II l'albumine fut de façon significative plus élevée et l'urée plus basse chez les femelles reprenant une activité ovarienne. Les résultats suggèrent que les femelles capables de maintenir leur condition physique pendant toute la période du vêlage auront un premier oestrus plus rapide que les femelles ayant perdu du poids. Les teneurs plus faibles en urée et plus fortes en albumine chez les animaux ayant un cycle reflètent probablement d'une meilleure efficacité dans la nutrition. Les demands en lactation furent compensées par l'altération due métabolisme azoté.