''Trygonorrhina'', also known as the fiddler rays or banjo rays, is a
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...
of
guitarfish
The guitarfish, also referred to as shovelnose rays, are a family, Rhinobatidae, of rays. The guitarfish are known for an elongated body with a flattened head and trunk and small, ray-like wings. The combined range of the various species is tro ...
, family Rhinobatidae. The two species are found along the eastern and southern coasts of
Australia. They are
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...
in nature, favoring shallow, sandy bays, rocky
reef
A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic component, abiotic processes—deposition (geology), deposition of ...
s, and
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families ( Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the ...
beds. The eastern fiddler is found to a depth of 120 m and the southern fiddler to a depth of 180 m.
[Aitken, K. (2002)]
Southern Fiddler Ray ''(Trygonorrhina dumerilii)'' & Eastern Fiddler Ray ''(Trygonorrhina faciata)''. Rhinobatidae
. ''Marine Themes''.
The flattened
pectoral fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...
discs of fiddler rays are shorter and more rounded than those of other guitarfishes. Their tails are slender, with a well-developed
caudal fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as s ...
and two triangular
dorsal fin
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...
s.
[McGrouther, M. (2006)]
Eastern Fiddler Ray, ''Trygonorrhina faciata''
''Australian Museum''. Their snouts are translucent.
The fiddler rays are also distinguished from other guitarfishes in that the anterior nasal flaps of their
nostril
A nostril (or naris , plural ''nares'' ) is either of the two orifices of the nose. They enable the entry and exit of air and other gasses through the nasal cavities. In birds and mammals, they contain branched bones or cartilages called t ...
s are expanded backwards and fused together into a nasal curtain that reaches the mouth.
Fiddler rays feed on bottoms
shellfish
Shellfish is a colloquial and fisheries term for exoskeleton-bearing aquatic invertebrates used as food, including various species of molluscs, crustaceans, and echinoderms. Although most kinds of shellfish are harvested from saltwater env ...
,
crabs, and
worm
Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always).
Worms vary in size from microscopic to over in length for marine polychaete worm ...
s, which they crush between their
jaw
The jaw is any opposable articulated structure at the entrance of the mouth, typically used for grasping and manipulating food. The term ''jaws'' is also broadly applied to the whole of the structures constituting the vault of the mouth and serv ...
s.
The eastern fiddler ray is known to
scavenge
Scavengers are animals that consume dead organisms that have died from causes other than predation or have been killed by other predators. While scavenging generally refers to carnivores feeding on carrion, it is also a herbivorous feeding b ...
from
fish trap
A fish trap is a trap used for fishing. Fish traps include fishing weirs, lobster traps, and some fishing nets such as fyke nets.
Traps are culturally almost universal and seem to have been independently invented many times. There are two main ...
s.
Like other guitarfishes, fiddler rays are
ovoviviparous
Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
. The
egg
An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
capsules of the southern fiddler ray are reported to be golden in colour, containing three
embryo
An embryo is an initial stage of development of a multicellular organism. In organisms that reproduce sexually, embryonic development is the part of the life cycle that begins just after fertilization of the female egg cell by the male sperm ...
s each.
It gives birth to litters of four to six young per breeding cycle.
Fiddler rays are harmless and easily approached by divers.
Southern fiddler rays are taken as
bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juven ...
by
commercial trawler
A fishing trawler is a commercial fishing vessel designed to operate fishing trawls. Trawling is a method of fishing that involves actively dragging or pulling a trawl through the water behind one or more trawlers. Trawls are fishing nets tha ...
s and by
recreational fishers; the flesh is of good quality and sold in small quantities.
The Magpie fiddler ray (previously ''Trygonorrhina melaleuca'') is now considered a variant of ''Trygonorrhina dumerilii''.
[Donnellan, S.C., Foster, R., Junge, C., Huveneers, C., Rogers, P., Kilian, A. & Bertozzi, T. (2015): Fiddling with the proof: the Magpie Fiddler Ray is a colour pattern variant of the common Southern Fiddler Ray (Rhinobatidae: ''Trygonorrhina''). ''Zootaxa, 3981 (3): 367–384.'']
Species
There are currently 2 recognized species in this genus:
* ''
Trygonorrhina dumerilii
''Trygonorrhina dumerilii'', the southern fiddler ray, is a species of cartilaginous fish in the Rhinobatidae family. The species is medium-sized with mainly yellow, black, and white colours. ''T.dumerilii'' has a maximum size of 1m, and is com ...
''
Castelnau, 1873 (Southern fiddler ray)
[
* '']Trygonorrhina fasciata
The eastern fiddler ray (''Trygonorrhina fasciata''), also called the banjo shark, fiddler ray, fiddler, green skate, magpie fiddler ray, parrit, southern fiddler ray or southern fiddler, is a species of fish in the Rhinobatidae family. It is en ...
'' J. P. Müller & Henle Henle can refer to:
*Friedrich Gustav Jakob Henle, a German physician, pathologist and anatomist (1809–1885)
** Loop of Henle in the kidney, named after Henle
*Fritz Henle, a photographer, known as "Mr. Rollei" for his use of the 2.25" square form ...
, 1841 (Eastern fiddler ray)
References
{{Taxonbar, from=Q3541202
Rhinobatidae
Taxa named by Friedrich Gustav Jakob Henle