-
The relationship between head shape, head musculature and bite force in caecilians (Amphibia: Gymnophiona)
-
Caecilians are enigmatic limbless amphibians that, with a few exceptions, all have an at least partly burrowing lifestyle. Although it has been suggested that caecilian evolution resulted in sturdy and compact skulls as an adaptation to their head-first burrowing habits, no relationship between skull shape and burrowing performance has been demonstrated to date. However, the unique dual jaw-closing mechanism and the osteological variability of their temporal region suggest a potential relationship between skull shape and feeding mechanics. Here, we explored the relationships between skull shape, head musculature and in vivo bite forces. Although there is a correlation between bite force and external head shape, no relationship between bite force and skull shape could be detected. Whereas our data suggest that muscles are the principal drivers of variation in bite force, the shape of the skull is constrained by factors other than demands for bite force generation. However, a strong covariation between the cranium and mandible exists. Moreover, both cranium and mandible shape covary with jaw muscle architecture. Caecilians show a gradient between species with a long retroarticular process associated with a large and pennate-fibered m. interhyoideus posterior and species with a short process but long and parallel-fibered jaw adductors. Our results demonstrate the complexity of the relationship between form and function of this jaw system. Further studies that focus on factors such as gape distance or jaw velocity will be needed in order to fully understand the evolution of feeding mechanics in caecilians.
Located in
Library
/
RBINS Staff Publications 2021
-
30 Years of Belgian North Sea Aerial Surveillance – Evolution, Trends, and Developments.
-
Located in
Library
/
RBINS Staff Publications 2023
-
Is vertebral shape variability in caecilians (Amphibia: Gymnophiona) constrained by forces experienced during burrowing?
-
Caecilians are predominantly burrowing, elongate, limbless amphibians that have been relatively poorly studied. Although it has been suggested that the sturdy and compact skulls of caecilians are an adaptation to their head-first burrowing habits, no clear relationship between skull shape and burrowing performance appears to exist. However, the external forces encountered during burrowing are transmitted by the skull to the vertebral column, and, as such, may impact vertebral shape. Additionally, the muscles that generate the burrowing forces attach onto the vertebral column and consequently may impact vertebral shape that way as well. Here, we explored the relationships between vertebral shape and maximal in vivo push forces in 13 species of caecilian amphibians. Our results show that the shape of the two most anterior vertebrae, as well as the shape of the vertebrae at 90% of the total body length, is not correlated with peak push forces. Conversely, the shape of the third vertebrae, and the vertebrae at 20% and 60% of the total body length, does show a relationship to push forces measured in vivo. Whether these relationships are indirect (external forces constraining shape variation) or direct (muscle forces constraining shape variation) remains unclear and will require quantitative studies of the axial musculature. Importantly, our data suggest that mid-body vertebrae may potentially be used as proxies to infer burrowing capacity in fossil representatives.
Located in
Library
/
RBINS Staff Publications 2022
-
Toxicodryas vexator Greenbaum, Allen, Vaughan, Pauwels, Wallach, Kusamba, Muninga, Mwenebatu, Mali, Badjedjea, Penner, Rödel, Rivera, Sterkhova, Johnson, Tapondjou and Brown, 2021. Eastern Black-and-Yellow Tree Snake. Diet.
-
We report a case of predation by an adult Eastern Black-and-Yellow Tree Snake Toxicodryas vexator (Serpentes : Colubridae) on a juvenile Lord Derby's Scaly-tailed Squirrel Anomalurus derbianus (Rodentia : Anomaluridae) in Yangambi, Tshopo Province, Democratic Republic of the Congo. This is the first documented interaction between these two species.
Located in
Library
/
RBINS Staff Publications 2022
-
Assessing the influences of bee’s (Hymnoptera: Apidae) floral preference on cashew (Anacardiacae) agronomics performances in Côte d’Ivoire.
-
This study aimed to assess the influence of bees’ floral preference on cashew agronomics performances in Côte d’Ivoire. Therefore, a sampling design with a total of 40 cashew trees preferred by bees and 40 trees that were not preferred by bees was established in 4 main producing regions. In addition, bees’ foragers and agronomics performances of trees were sampled. As results, a total of 46 bee’ species with a foraging activity of 4±0.32 visits per minute were observed. Apis mellifera (60% of visits, with 2.27±0.17 of visitors per minute) followed by Meliponula bocandei (23% of visits with 0.91±0.18 of visits per minute) contributes significantly to the reproduction of cashew trees, compare to the 44 other bees’ species (17% of visits; with an activity of 0.69±0.03 of visitors per minute). The preferred trees recorded 40.54±0.57 kg of nuts per tree, with 18.39±0.48 fruits per inflorescence, including 37.12±0.4% of useful kernel per raw nut (yield ratio of 65.45±0.66 pound of useful kernel). Conversely, the non-preferred trees obtained 5.24±0.44kg of nuts per tree, with 1.7±0.21 fruits per inflorescence, including 28.69±0.65% of useful kernel per raw nut (50.6±1.15 pound of useful kernel). Hence, the foraging preference of these two Apidae significantly increased the fruiting rate (83.7±0.01%), the yields (87.08±0.0%), and the kernel rate (22.68±1.76%) in raw cashew nuts. Based in these results, we suggest the foraging preference of Apis mellifera as good indicator of high-yielding cashew plants. Moreover, we suggests combination of apicultural and meliponicultrual in cashew farming to boost the yields and farmers livelihoods.
Located in
Library
/
RBINS Staff Publications 2022
-
Ocean acidification modifies behaviour of shelf seabed macrofauna: A laboratory study on two ecosystem engineers, Abra alba and Lanice conchilega
-
The feeding activity and burrow ventilation by benthic invertebrates importantly affect the biodiversity and functioning of seafloor sediments. Here we investigated how ocean acidification can modify these behavioural activities in two common and abundant macrofaunal ecosystem engineering species in temperate continental shelf communities: the white furrow shell Abra alba and the sand mason Lanice conchilega. Using time-lapse imagery and sediment porewater hydraulic signatures we show that both species adapt their behaviour in response to predicted future pH conditions (-0.3 units). During a three-week laboratory experiment, A. alba reduced the duration per feeding event when suspension and deposit feeding (by 86 and 53%, respectively), and almost completely ceased suspension feeding under reduced seawater pH in comparison to ambient seawater pH (pH ~ 8.2). This behavioural change reduces the intake of low pH water during feeding and respiration. L. conchilega increased its piston-pumping frequency by 30 and 52%, respectively, after one and two weeks of exposure to future pH conditions (-0.3 units) relative to ambient conditions. This change in irrigation activity suggests higher metabolic demands under low seawater pH, and also extended low water column pH conditions deeper into the seafloor. Because the distribution of other populations depends on the physicochemical setting by our focal species, we argue that the demonstrated behavioural plasticity will likely have cascading effects on seafloor diversity and functioning, highlighting the complexity of how ocean acidification, and climate change in general, will affect seafloor ecology.
Located in
Library
/
RBINS Staff Publications 2023
-
Assessment of PRISMA water reflectance using autonomous hyperspectral radiometry
-
Hyperspectral remote sensing reflectance (Rrs) derived from PRISMA in the visible and infrared range was evaluated for two inland and coastal water sites using above-water in situ reflectance measurements from autonomous hyper- and multispectral radiometer systems. We compared the Level 2D (L2D) surface reflectance, a standard product distributed by the Italian Space Agency (ASI), as well as outputs from ACOLITE/DSF, now adapted for processing of PRISMA imagery. Near-coincident Sentinel-3 OLCI (S3/OLCI) observations were also compared as it is a frequent data source for inland and coastal water remote sensing applications, with a strong calibration and validation record. In situ measurements from two optically diverse sites in Italy, equipped with fixed autonomous hyperspectral radiometer systems, were used: the REmote Sensing for Trasimeno lake Observatory (RESTO), positioned in a shallow and turbid lake in Central Italy, and the Acqua Alta Oceanographic Tower (AAOT), located 15 km offshore from the lagoon of Venice in the Adriatic Sea, which is characterised by clear to moderately turbid waters. 20 PRISMA images were available for the match-up analysis across both sites. Good performance of L2D was found for RESTO, with the lowest relative (Mean Absolute Percentage Difference, MAPD 25\%) and absolute errors (Bias 0.002) in the bands between 500 and 680 nm, with similar performance for ACOLITE. The lowest median and interquartile ranges of spectral angle (SA 8°) denoted a more similar shape to the RESTO in situ data, indicating pigment absorption retrievals should be possible. ACOLITE showed better statistical performance at AAOT compared to L2D, providing R2 0.5, Bias 0.0015 and MAPD 35\%, in the range between 470 and 580 nm, i.e. in the spectral range with highest reflectances. The addition of a SWIR based sun-glint correction to the default atmospheric correction implemented in ACOLITE further improved performance at AAOT, with lower uncertainties and closer spectral similarity to the in situ measurements, suggesting that ACOLITE with glint correction was able to best reproduce the spectral shape of in situ data at AAOT. We found good results for PRISMA Rrs retrieval in our study sites, and hence demonstrated the use of PRISMA for aquatic ecosystem mapping. Further studies are needed to analyse performance in other water bodies, over a wider range of optical properties.
Located in
Library
/
RBINS Staff Publications 2022
-
Spiegelhuis Zoutleeuw. Natuursteendecoratie in de voorgevel. Studie t.a.v. Jan Peeters, eigenaar
-
Located in
Library
/
RBINS Staff Publications 2022
-
Archeologische opgraving Noorderterras. Natuursteen in de depositie van ballaststeen en hergebruikte bouwmaterialen van de Burcht, Scheldekaaien/Noorderterras. Studie uitgevoerd in opdracht van de stadsdienst Archeologie, Onroerend Erfgoed Stad Antwerpen
-
Located in
Library
/
RBINS Staff Publications 2022
-
Mise au jour d’une nouvelle partie de la collection de François Beaufays (dit « l’Horloger ») contenant des vestiges humains de Spy (Prov. de Namur, BE)
-
Located in
Library
/
RBINS Staff Publications 2023 OA