Going deeper, darker and further: Observations charting an egg nursery, a range and depth extension for the deep-sea spiny tailed skate Bathyraja spinicauda, first records from the Mid Atlantic Ridge

Seamount coral reefs are egg case nurseries for deep‐sea skates

“…Very few and only egg cases visibly fouled or degraded were found associated with sand and other substrata on seamount bases and continental slope, suggesting that egg cases are either laid there infrequently or possibly have been dislodged after hatching and drifted down to seamount bases. These patterns differ from those reported for both species elsewhere; that is, a large number of to 2.37 C warmer than B. richardsoni in 3000 m, prospectively accelerating embryonic development (Grubbs & Musick, 2007;Hoff, 2007Hoff, , 2008Hume, 2019;Lennon et al, 2021;Salinas-de-Le on et al, 2018). Because the embryonic development time of skates can be exceptionally long, e.g., 3-4 years (Hoff, 2008;Salinas-de-Le on et al, 2018), their egg cases are particularly exposed to both biofouling (Hoff, 2009) and predation (Cox et al, 1999;Knight et al, 1996).…”

“…Although rarely detected in the deep sea, skate egg case nurseries have been reported from recent photographic surveys within relatively small areas (100 s m 2 ) using ROV (Hebrides Terrace Seamount, Rockall Trough, North Atlantic, Henry et al ., 2016; Sea of Japan, Hunt et al ., 2011; and the Mid‐Atlantic Ridge, Lennon et al ., 2021) and AUV (Schulz Bank, Arctic Mid‐Ocean Ridge, North Atlantic, Meyer et al ., 2019), and over a large area (1000 s km 2 ) using trawl surveys (Eastern Bering Sea, Hoff, 2016) or submersible (Southern California Bight, Love et al ., 2008). The small‐scale photographic surveys were able to identify egg case nursery habitats in detail with fine spatial resolution but each in only one location, whereas the large number of trawl samples combined over 9 years was able to pinpoint eight egg deposition sites within a large ocean region (Hoff, 2016).…”

“…Egg cases in the shallower part of the adult skate depth range ( c . 1300 m) are bathed in warmer water than the deeper range: 0.66 to 1.67°C warmer than A. hyperborea in 2000 m, and 1.75 to 2.37°C warmer than B. richardsoni in 3000 m, prospectively accelerating embryonic development (Grubbs & Musick, 2007; Hoff, 2007, 2008; Hume, 2019; Lennon et al ., 2021; Salinas‐de‐León et al ., 2018). Because the embryonic development time of skates can be exceptionally long, e.g ., 3–4 years (Hoff, 2008; Salinas‐de‐León et al ., 2018), their egg cases are particularly exposed to both biofouling (Hoff, 2009) and predation (Cox et al ., 1999; Knight et al ., 1996).…”

A holistic and comprehensive data approach validates the distribution of the critically endangered flapper skate (Dipturus intermedius)

“…600 m [and D. laevis can be found to 1000 m depth (Dulvy et al ., 2006; Kulka et al ., 2020)]. Whilst geographically separate and with distinguishing morphological features (1), these sister taxa could be the results of allopatric speciation (Carugati et al ., 2021), given that they are separated by a barrier of cold water from the east Greenland Current, beyond which only deep‐water skate species are found (Ebert & Stehmann, 2013; Kulka et al ., 2020; Lennon et al ., 2021). Beyond this supposition, these findings have important consequences for the management for these species.…”

Of three sharks and one chimaera: varied habitat preferences across a latitudinal range revealed by coastal and offshore surveys

“…This creates different requirements for reproduction and early life stages, especially with respect to the required energy and nursery areas, but also the timing and gestation periods. Egg‐laying species have variable substrate requirements and need to find waters with high oxygenation to lay their eggs (Barnett et al ., 2019; Lennon et al ., 2021), whereas aplacental viviparous species invest and need a lot of energy during their longer gestation periods, and may frequently return to somewhat sheltered areas, often referred to as nursery grounds and often associated with hatching, birthing or pupping [but see Heupel et al . (2007) for a critical discussion on the concept of nursery areas].…”