Stereo Vision 3D Tracking of Multiple Free-Swimming Fish for Low Frame Rate Video

3D multiple fish tracking has gained a significant growing research interest to quantify fish behavior. However, most tracking techniques have used a high frame rate that is currently not viable for real-time tracking applications. This study discusses multiple fish tracking techniques using low frame rate sampling of stereo video clips. The fish are tagged and tracked based on the absolute error of predicted indices using past and present fish centroid locations and a deterministic frame index. In the predictor sub-system, the linear regression and machine learning algorithms intended for nonlinear systems, such as Adaptive Neuro-Fuzzy Inference System (ANFIS), symbolic regression, and Gaussian Process Regression (GPR), were investigated. Results have shown that in the context of tagging and tracking accuracy, the symbolic regression attained the best performance, followed by the GPR, i.e., 74% to 100% and 81% to 91%, respectively. Considering the computation time, symbolic regression resulted in the highest computing lag of approximately 946 ms per iteration, whereas GPR achieved the lowest computing time of 39 ms

Convergent, Parallel and Correlated Evolution of Trophic Morphologies in the Subfamily Schizothoracinae from the Qinghai-Tibetan Plateau

Schizothoracine fishes distributed in the water system of the Qinghai-Tibetan plateau (QTP) and adjacent areas are characterized by being highly adaptive to the cold and hypoxic environment of the plateau, as well as by a high degree of diversity in trophic morphology due to resource polymorphisms. Although convergent and parallel evolution are prevalent in the organisms of the QTP, it remains unknown whether similar evolutionary patterns have occurred in the schizothoracine fishes. Here, we constructed for the first time a tentative molecular phylogeny of the schizothoracine fishes based on the complete sequences of the cytochrome b gene. We employed this molecular phylogenetic framework to examine the evolution of trophic morphologies. We used Pagel's maximum likelihood method to estimate the evolutionary associations of trophic morphologies and food resource use. Our results showed that the molecular and published morphological phylogenies of Schizothoracinae are partially incongruent with respect to some intergeneric relationships. The phylogenetic results revealed that four character states of five trophic morphologies and of food resource use evolved at least twice during the diversification of the subfamily. State transitions are the result of evolutionary patterns including either convergence or parallelism or both. Furthermore, our analyses indicate that some characters of trophic morphologies in the Schizothoracinae have undergone correlated evolution, which are somewhat correlated with different food resource uses. Collectively, our results reveal new examples of convergent and parallel evolution in the organisms of the QTP. The adaptation to different trophic niches through the modification of trophic morphologies and feeding behaviour as found in the schizothoracine fishes may account for the formation and maintenance of the high degree of diversity and radiations in fish communities endemic to QTP

Convergent and parallel evolution in life habit of the scallops (Bivalvia: Pectinidae)

<p>Abstract</p> <p>Background</p> <p>We employed a phylogenetic framework to identify patterns of life habit evolution in the marine bivalve family Pectinidae. Specifically, we examined the number of independent origins of each life habit and distinguished between convergent and parallel trajectories of life habit evolution using ancestral state estimation. We also investigated whether ancestral character states influence the frequency or type of evolutionary trajectories.</p> <p>Results</p> <p>We determined that temporary attachment to substrata by byssal threads is the most likely ancestral condition for the Pectinidae, with subsequent transitions to the five remaining habit types. Nearly all transitions between life habit classes were repeated in our phylogeny and the majority of these transitions were the result of parallel evolution from byssate ancestors. Convergent evolution also occurred within the Pectinidae and produced two additional gliding clades and two recessing lineages. Furthermore, our analysis indicates that byssal attaching gave rise to significantly more of the transitions than any other life habit and that the cementing and nestling classes are only represented as evolutionary outcomes in our phylogeny, never as progenitor states.</p> <p>Conclusions</p> <p>Collectively, our results illustrate that both convergence and parallelism generated repeated life habit states in the scallops. Bias in the types of habit transitions observed may indicate constraints due to physical or ontogenetic limitations of particular phenotypes.</p

Traditional Taxonomic Groupings Mask Evolutionary History: A Molecular Phylogeny and New Classification of the Chromodorid Nudibranchs

Chromodorid nudibranchs (16 genera, 300+ species) are beautiful, brightly colored sea slugs found primarily in tropical coral reef habitats and subtropical coastal waters. The chromodorids are the most speciose family of opisthobranchs and one of the most diverse heterobranch clades. Chromodorids have the potential to be a model group with which to study diversification, color pattern evolution, are important source organisms in natural products chemistry and represent a stunning and widely compelling example of marine biodiversity. Here, we present the most complete molecular phylogeny of the chromodorid nudibranchs to date, with a broad sample of 244 specimens (142 new), representing 157 (106 new) chromodorid species, four actinocylcid species and four additional dorid species utilizing two mitochondrial markers (16s and COI). We confirmed the monophyly of the Chromodorididae and its sister group relationship with the Actinocyclidae. We were also able to, for the first time, test generic monophyly by including more than one member of all 14 of the non-monotypic chromodorid genera. Every one of these 14 traditional chromodorid genera are either non-monophyletic, or render another genus paraphyletic. Additionally, both the monotypic genera Verconia and Diversidoris are nested within clades. Based on data shown here, there are three individual species and five clades limited to the eastern Pacific and Atlantic Oceans (or just one of these ocean regions), while the majority of chromodorid clades and species are strictly Indo-Pacific in distribution. We present a new classification of the chromodorid nudibranchs. We use molecular data to untangle evolutionary relationships and retain a historical connection to traditional systematics by using generic names attached to type species as clade names

Phylogenetic convergence and multiple shell shape optima for gliding scallops (Bivalvia: Pectinidae)

How often, and to what extent, do similar ecologies elicit distantly related taxa to evolve towards the same phenotype? Alike phenotypes can arise when species exploit a common trophic niche and evolutionarily respond in a congruent manner to those selective constraints required for particular function or biomechanical task (Herrel et al., 2008; Vincent et al., 2009; Adams & Nistri, 2010). This is the pattern of convergence, the repeated evolution towards similar phenotypes among multiple lineages that ancestrally lack the trait (Stayton, 2015). As such, convergent evolution is regularly treated as evidence for adaptation (Harvey & Pagel, 1991; Larson & Losos, 1996). Some of the best known examples of convergent evolution are seen in the similarity in body plans of the succulent plants in Euphorbiaceae and Cactaceae (Alvarado-Cárdenas et al., 2013) and Old and New World anteaters (Beck et al., 2006), or the similarity of skull shape between the marsupial Thylacine (Tasmanian wolf) and that of the placental canids (Wroe & Milne, 2007; Goswami et al., 2011).This is the peer reviewed version of the following article: Serb, J. M., Sherratt, E., Alejandrino, A. and Adams, D. C. (2017), Phylogenetic convergence and multiple shell shape optima for gliding scallops (Bivalvia: Pectinidae). J. Evol. Biol., 30: 1736–1747, which has been published in final form at doi:10.1111/jeb.13137 . This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving.</p

Implementation of inverse kinematics for crop-harvesting robotic arm in vertical farming

The world population is expected to increase to 9.8 billion in 2050 according to United Nations. With this, scarcity of food and space will further be a major concern. This study proposes a framework which used initializing, processing, and directing applied to an inverse kinematics based robotic arm. An automatized approach in addressing the foreseeable problem on providing nutritional plant-based food considering that cities are becoming highly-urbanized was developed. Wall gardening used for vertical farming or urban farming is a technique by which there are sets of rows and columns of pockets installed over a wall. These pockets are filled with soil or other planting bases (i.e. water for hydroponics) for the seedlings to grow. A robotic arm is manually set to point on a specific pocket where a crop has grown. Using inverse kinematics, the set points determine the joint angles. This then targets the pockets and the end-effector of the robot arm performs a grip to the roots of the crops. The robotic arm then moves to its initial point, technically pulling up the crop. After positioning to the initial point, the arm directs to the side of the wall, where a container is located. The end-effector opens to drop the crop carefully into the container. The research study is simulated using MATLAB and Universal Robots. The results show that it can only yield 85.42% of the crops.© 2019 IEEE