Yet, in the North Pacific, its “cousin” is the salmon shark (L. ditropsis). In fact, it and the salmon shark are the thickest-bodied sharks in the Lamnidae family (length-depth ratio almost 4.5); due to this, they have the stiffest swimming style. They completely move their tails while holding their bodies rather stiffly; so while they have a powerful propulsive power/energy efficiency, they aren’t very flexible. Due to this, they have larger gills, allowing more oxygen.
Their skin, unlike many sharks, is actually soft (though I’ve never felt one, but I’ll admit I’m intrigued by this shark who supposedly feels like “velvet”). Their dermal denticles are tiny and flat.
Southern Hemisphere sharks are smaller and the two sexes are similar in size, with males and females being closet to 2.0 m (6.6 ft) and 2.1 m (6.9 ft) respectively. The max weight of 135 kg (298 lb).
Interesting fact: Porbeagle populations in these two hemispheres (North and South) seem to be completely separate from one another! Only one individual has been recorded to cross the Atlantic, making a trek about 4,260 km (2,650 miles). From where to where, you ask? Good question. Our friend here decided to leave Ireland waters to visit good ole’ Canada! What a trek!
Both populations of this species are known to seasonally migrate. This species is also known to segregate through size and/or sex. In the W North Atlantic, these sharks will spend spring in the deep, cold waters off of Nova Scotia, then they’ll migrate north for late summer/fall to the shallower waters of Newfoundland/Gulf of St. Lawrence. Once December rolls around, mature females will head south- a swim over 2,000 km (1,200 miles)- into the Sargasso Sea to give birth in deep, cool waters. In the E North Atlantic, these sharks are thought to spend spring/summer in shallow waters, and migrate north in the winter to spent time in deep, offshore water.
Speaking of pups and pupping, they are aplacental viviparous and young do perform oophagy (yum, shark cannibalism).
Litter sizes are small, with females only giving birth to about 4 pups every year.
These animals are opportunistic hunters, feeding on bony fishes and cephalopods. Like most sharks in its family, they are fast swimmers and energetic. They can be found swimming either in groups or in solitude. These are one of the only fish to exhibit play behavior.
Yep. These sharks play. They’ve been seen rolling and wrapping themselves in kelp (which may be exploration or them feeding). But they’re also known to chase each other around and toy with anything floating on the water’s surface.
These sharks have only a few encounters, but not all attacks have been 100% confirmed as the porbeagle. It’s known a popular game fish, with its meat and fins being highly valued. Yet, due to its low reproductive cycle, commercial fishing (usually Norwegian longliners) has led to stock collapses of this North hemisphere population.
This shark is still being fished, intentionally and as bycatch. Due to varying degrees of fishing monitoring/management, the IUCN has assessed this shark as Vulnerable worldwide, and either as Endangered/Critically Endangered in parts of the Northern Hemisphere.