Biodiversity, Life History, and Conservation of Northeastern Pacific Chondrichthyans
The sharks, batoids, and chimaeras, collectively the class Chondrichthyes, are one of the most successful groups of fishes, with over 1250 species globally. Recent taxonomic revisions have increased their diversity by about 20% over the past 17 years (2000–2016). The Northeast Pacific Ocean is one of the top 20 most diverse regions/countries on the globe with 77 chondrichthyan species, a number less than a quarter that of the most species-rich area (Australia) but that has increased by 10% since 2000 to include three new species (two skates and a chimaera). In this chapter we discuss the species richness of chondrichthyans occurring in the Northeast Pacific Ocean, characterize their life histories, briefly review several fisheries, and summarize the conservation status of those chondrichthyans occurring in the region. Detailed descriptions and evaluations of fisheries can be found in Chapter 7 of AMB Volume 78.
Color aberrations in Chondrichthyan fishes: first records in the genus Bathyraja (Chondrichthyes: Rajiformes: Arhyncobatidae)
Two softnose skate specimens with abnormal coloration, one complete albino and one partial albino (leucistic), were captured during fishery-independent trawl surveys. The complete albino specimen was collected in 2007 in Prince William Sound, Alaska, and the leucistic specimen was collected in 2011 off northern California. Based upon meristic and morphometric measurements, the albino skate specimen was identified as the Aleutian Skate, Bathyraja aleutica, and the leucistic skate specimen was identified as the Roughtail Skate, Bathyraja trachura. These are the first documented cases of any type of albinism in the genus Bathyraja. A comprehensive review encompassing reported cases of any type of albinism in Chondrichthyans from peer-reviewed literature to-date is provided.