Tessellated calcified cartilage (TCC) is a hallmark of the chondrichthyan skeleton, yet its development early in ontogeny across the four major groups (batoids, galeomorphs, squalomorphs, and holoceph...

Many studies on elasmobranchs, sharks and batoids (rays, skates and guitarfishes), have focused on the factors responsible for biomass decline, but little attention has been paid to the factors that affect species richness. We used the software package ModestR to determine the geographical distribution of all valid marine elasmobranch species (512 species of sharks and 619 species of batoids), thereby making it possible to determine the species composition of the elasmobranch community in any area worldwide. The primary aim of this study was to identify the factors associated with the species richness of elasmobranchs. The data were analyzed using multiple regressions and Support Vector Machine (SVM) in cells of 1º× 1º with the analyzed abiotic variables being bathymetry, chlorophyll a, sea surface temperature, photosynthetically available radiation, pH, cloud cover, the concentrations of calcite, silicate, phosphate and nitrate, salinity, particulate organic carbon, diffuse attenuation and dissolved oxygen. The mean area of occupancy of the species was used as an indicator of niche occupancy. The model performed with SVM explained 97 and 99 % of the variance observed in the species richness of batoids and sharks, respectively. Mean area of occupancy, temperature and bathymetry were the variables with a higher contribution to the variance observed in both sharks and batoids. The negative residuals of the model performed with SVM indicated areas with lower than predicted species richness. These may be potential areas with undiscovered and/or unregistered species, or areas with decreased species richness due to the negative effect of anthropogenic factors, i.e. overfishing

The Late Jurassic fossil deposits of southern Germany, collectively known as the ’Solnhofen Archipelago’, are one of the world’s most important sources of Mesozoic vertebrates. Complete skeletons of c...

Currently, all the extant batoids species from the family Pristidae are listed as critically endangered and their populations are decreasing. Multiple efforts have been made in Mexico to record the p...

The Mediterranean Sea is home to some of the world’s most threatened shark and ray species, yet many aspects of their biology and behaviour remain poorly understood. In this context, the study “Biolog...

After completing Bahrain’s first environmental DNA (eDNA) surveys in the hottest sea on the planet, one question lingered quietly behind the science: How do we know exactly who we are detecting? eDNA ...

In the Colombian Caribbean, artisanal fishing is more than an economic activity, it is a way of life deeply rooted in coastal culture. Yet this practice also intersects with one of the most vulnerable...

Caught this guy as a part of my ongoing research on batoids. They're critically endangered.

Caught this guy as a part of my ongoing research on Batoids in Mumbai.