- Chantel Elston
South Africa's Lesser Known Chondrichthyans
Our last blog post was dedicated to the most charismatic sharks one can find along the South African coastline, so this time we thought we’d share the love with some of the lesser known species.
While the majority of South African chondrichthyan species are indeed sharks (our coastline is home to 117 shark species that we know of at present), our waters also play host to 79 batoid species (i.e. rays and skates) as well as 8 chimaera species (although there are probably more species waiting to be described).
The lack of knowledge over these batoid and chimaera species is overwhelming, both in the scientific realm as well as in the public sphere (tell me, do you even know what a chimaera is?). Now don’t worry it’s not your fault – these less charismatic species have been long overlooked in the scientific world, but this is slowly starting to change.
Even though batoids and chimaeras may not be as ‘cool’ as sharks, they play important roles in our oceans. For example, many ray species display what is called ‘bioturbative feeding behaviours’ – which simply means that they stir up the sediment by digging in sandy bottoms for yummy worms and shrimps to eat. This feeding behavior really alters the sandy plains of the ocean floors and oxygenates the sediment among other important things.
So, to shed some light on the lesser loved (but just as important) species, here are five species of South African batoids and chimaeras paired with their lesser known terrestrial counterparts.
1. PORCUPINE RAY (Urogymnus asperrimus)
Terrestrial counterpart
Porcupine – while the porcupine ray is the only species of stingray to lack the stinging spine on it’s tail, it’s back is covered with sharp thorns for defense, much like a terrestrial porcupine.
Range
The porcupine ray prefers warmer waters and thus only occurs on the east coast, from Natal northwards.
Where and when
An inshore species that occurs on the bottom of shallow waters.
Special notes
It has a wide range throughout the Indian and Indo-West Pacific oceans but is hardly encountered and is thus considered rare. This also means that information for these species is very limited.
2. ST. JOSEPH / CAPE ELEPHANTFISH (Callorhinchus capensis)
Terrestrial counterpart
Cape elephant shrew – both have long noses reminiscent of an elephant trunk, giving rise to their common names. Both are endemic to South Africa.
Range
Almost the whole South African coastline, from Namibia to Natal, but it is most common on the west and south coasts.
Where and when
Occurs mostly inshore and in shallow bays but can be found up to 374m depth. This species is also a bottom dweller.
Special notes
The only chimaera on our list, the St. Joseph actually makes for good eating and there is a directed fishery that operates in St. Helena Bay.
3. SPOTTED EAGLE RAY (Aetobatus narinari)
Terrestrial counterpart
African fish eagle – both display active and powerful prowess in their respective habitats; the fish eagle in the air and the eagle ray in the water. Both are also considered generalist predators and can consume a relatively wide variety of prey.
Range
On the east coast, from Knysna up to Natal
Where and when
Shallow inshore waters, often near reefs, both in the bottom and at the surface of the water column.
Special notes
The spotted eagle ray can occur alone but also in large groups and they are known to use their powerful bodies to propel themselves up and out of the water before crashing back down.
4. MANTA RAY (Manta alfredi)
Terrestrial counterpart
African civet – both have unique markings that can be used to identify individuals. Manta rays have unique spots and lines on their undersides, and African civets have unique spots on their coats.
Range
On the east coast, from Natal northwards
Where and when
Inshore shallow waters, a pelagic species occurring in the water column.
Special notes
This is probably the most charismatic ray species owing to its impressive size (between 3-5m wide) and gentle nature. Despite its large size, this species filters tiny plankton out of the water to sustain itself.
5. AFRICAN PYGMY SKATE (Neoraja stehmanni)
Terrestrial counterpart
Dwarf mongoose - both for their dwarfish sizes with the skate only reaching 20cm wide and the mongoose only reaching 26cm long.
Range
On the west coast of South Africa from the Orange river mouth to south of the Agulhas Bank.
Where and when
This skate occurs along the sandy bottoms of deeper waters from 292m – 1025m depth.
Special notes
Almost no information is available for these skates – we don’t even know what they eat!
#rays #chimaera #raysneedlovetoo #Elasmobranchs #SmallFive #Batoids