Platyrhinoidis triseriata (Thornback Fanray) Taxidermy

[MarcoSr]

I haven’t posted pictures of a taxidermy ray in a while, so below are pictures of a Platyrhinoidis triseriata (Thornback Fanray) that I recently purchased.  I wasted a lot of time trying to id this ray thinking it was a skate, family Rajidae, or a softnose skate, family Arhynchobatidae.  However, the teeth and caudal fin didn’t look right for a skate and I finally realized it was Fanray.  My go to book to id these ray specimens is Last, White, de Carvalho, Seret, Stehmann, Naylor 2016 Rays of the World.  I try to use the same terminology used in this book with the exception that I use placoid scales instead of dermal denticles.

 

Below is a picture and some information on Platyrhinoidis triseriata (Thornback Fanray) from Last 2016.  Note that the ray in the picture is male with visible claspers and the ray in this post is female.  Also note that colors in taxidermy specimens usually don’t remain true especially colors like white.

 

 

 

 

Here are pictures of the ray (disc 6 inches long by 7 inches wide, tail 9.5 inches long, total length 15.5 inches ) dorsal and ventral views:

 

 

 

 

 

This ray is completely covered by placoid scales which is unusual for a ray.

 

Placoid scales between the eyes on the dorsal side:

 

 

 

 

Placoid scales under the mouth ventral side:

 

 

 

 

Placoid scales on base of the tail ventral side:

 

 

 

 

Placoid scales on the caudal fin:

 

 

 

 

The dermal thorns on this specimen helped with its ID.

 

Dermal thorns on the anterior margins of the disc.  This is unusual for rays:

 

 

 

 

Dermal thorns on the snout tip.  This is also unusual:

 

 

 

 

Rows of widely separated dermal thorns on base of tail:

 

 

 

 

Shoulder dermal thorns on the left and right of the median thorns:

 

 

 

 

 

Large preorbital dermal thorn and orbital dermal thorns left and right eye:

 

 

 

 

 

Note:  This specimen does have dermal thorns between the two dorsal fins which doesn’t match Last 2016 for Platyrhinoidis triseriata.    However, no other Fanray is as close a match as Platyrhinoidis triseriata is for this specimen.

 

 

The tail fins helped with this ID especially the caudal fin.

 

 

1^st dorsal fin:

 

 

 

 

2^nd dorsal fin:

 

 

 

 

Caudal fin:

 

 

 

 

Oronasal region and tooth band mouth (35 mm):

 

 

 

 

Close up of the jaws left side:

 

 

 

 

Close up of a few teeth left side:

 

 

 

 

It really is difficult to ID skates and rays even with a reference like Last 2016.  I rarely get a 100% match to all of the Last 2016 criteria.

 

Marco Sr.

[Tidgy's Dad]

I've rather missed these threads, though i'm not a huge fan of taxidermy and always feel rather sorry for the fish, I do understand a certain scientific value, within reason, and it's good to see another one and they're very interesting with super pictures. 

And i received from Santa a little jaw and dorsal fins of a little shark as well. 

Thanks for sharing.

[grandpa]

38 minutes ago, Tidgy's Dad said:

always feel rather sorry for the fish,

But Adam, look at the smile on that face.   Does the fishie not look happy to you? 

[MarcoSr]

37 minutes ago, Tidgy's Dad said:

I've rather missed these threads, though i'm not a huge fan of taxidermy and always feel rather sorry for the fish, I do understand a certain scientific value, within reason, and it's good to see another one and they're very interesting with super pictures. 

And i received from Santa a little jaw and dorsal fins of a little shark as well. 

Thanks for sharing.

 

It is unfortunate that millions of sharks and rays get caught each year for food.  I don't support trophy fishing but people do need to eat.  There have been massive worldwide declines in the number of sharks and rays over the last fifty years.  In the near future, taxidermy specimens may be all that remain of a number of species of sharks and rays.  This specimen is from a collection from the 1970s so it has unfortunately been dead for a good while.

 

Marco Sr.

[MarcoSr]

7 minutes ago, grandpa said:

But Adam, look at the smile on that face.   Does the fishie not look happy to you? 

 

I do feel sorry for the ray.  I don't fish.  But the only way I can understand and better ID shark and ray fossil teeth, placoid scales, dermal denticles etc. is by studying extant examples.  Most fossil papers and articles really don't help me much.

 

Marco Sr.

[Mahnmut]

Great fotos.

Taxydermy from old collections like this one is the only kind I would accept for my collection. As a fan of natures diversity I don´t want to be part of its destruction.

Concerning people needing to eat: a relatively high percentage of the sharks killed is not eaten as a whole, but only "finned" for  delicacy soup.

That´s not need for food.

Best Regards.

J

[MarcoSr]

6 hours ago, Mahnmut said:

Great fotos.

Taxydermy from old collections like this one is the only kind I would accept for my collection. As a fan of natures diversity I don´t want to be part of its destruction.

Concerning people needing to eat: a relatively high percentage of the sharks killed is not eaten as a whole, but only "finned" for  delicacy soup.

That´s not need for food.

Best Regards.

J

 

Fining should be outlawed world wide with strict enforcement.  It is a very cruel and destructive process.  If a shark or ray is killed for food every part should be used.  The amount of partially dissolved plastics and other pollutants in a lot of areas in the oceans is also taking a toll  by being ingested by sharks and rays.  Between over-fishing and pollution we will lose many species to extinction.  Really sad.  I only buy taxidermy specimens from really old collections.

 

Marco Sr.

[sagacious]

Marco Sr,

 

Here are a few quick photos for comparison purposes with your female specimen.  The jaws and dermal denticles are from an approx. 600mm male P triseriata found washed-up dead on Dillon's Beach near  Tomales Bay, CA, and retained under a California Sportfishing license.  I often find a few dead thornback rays washed up on the beach during/after the breeding season, same as with Galeorhinus galeus and Mustelus sp.  

 

Below are dermal thorn from the two lateral rows. The largest measure approx. 7x5.5 mm across the base.

[sagacious]

Here are dermal thorns from the medial row.  The bases are thicker, more robust and show more pronounced striations.  The largest measure approx. 8x6 mm. 

 

[sagacious]

Jaws labial view, 70 mm wide.  

 

[sagacious]

Lingual view.

 

[sagacious]

Closeup of upper and lower teeth, lingual view.

 

[MarcoSr]

9 hours ago, sagacious said:

Marco Sr,

 

Here are a few quick photos for comparison purposes with your female specimen.  The jaws and dermal denticles are from an approx. 600mm male P triseriata found washed-up dead on Dillon's Beach near  Tomales Bay, CA, and retained under a California Sportfishing license.  I often find a few dead thornback rays washed up on the beach during/after the breeding season, same as with Galeorhinus galeus and Mustelus sp.  

 

Below are dermal thorn from the two lateral rows. The largest measure approx. 7x5.5 mm across the base.

 

 

Wow, really nice jaw and dermal thorns.  Great job of cleaning and processing.  Did you do that?

 

The best way to tell the fanrays from the skates is by the tail fins especially the caudal fin.  The fanrays and the skates don't have caudal stings like the sting rays.  The dermal thorns look extremely similar.  The teeth show sexual differences in a lot of ray/skate species so it is hard to compare male and female teeth.  Also so many of the rays and skates have very similar, almost identical teeth.  There are currently 5 species of fanrays, 154 species of skates and 104 species of softnose skates.  Plus there are hundreds of rays and skates in other families.  So it takes a while to id a specimen.   P triseriata is found along the California coast and does reach a maximum size of 91 cm total length.

 

Marco Sr.

[Coco]

Hi,

 

Sagacious, what means "P." in "P. triseriata" ?

 

Nice dermal thorns.

 

11 hours ago, sagacious said:

Marco Sr,

 

Here are a few quick photos for comparison purposes with your female specimen.  The jaws and dermal denticles are from an approx. 600mm male P triseriata found washed-up dead on Dillon's Beach near  Tomales Bay, CA, and retained under a California Sportfishing license.  I often find a few dead thornback rays washed up on the beach during/after the breeding season, same as with Galeorhinus galeus and Mustelus sp.  

 

Below are dermal thorn from the two lateral rows. The largest measure approx. 7x5.5 mm across the base.

Coco

[Coco]

Sorry, I hadn't see the complete name in the title (red smilie...).

 

Coco

[sagacious]

13 hours ago, MarcoSr said:

 

Wow, really nice jaw and dermal thorns.  Great job of cleaning and processing.  Did you do that?

 

The best way to tell the fanrays from the skates is by the tail fins especially the caudal fin.  The fanrays and the skates don't have caudal stings like the sting rays.  The dermal thorns look extremely similar.  The teeth show sexual differences in a lot of ray/skate species so it is hard to compare male and female teeth.  Also so many of the rays and skates have very similar, almost identical teeth.  There are currently 5 species of fanrays, 154 species of skates and 104 species of softnose skates.  Plus there are hundreds of rays and skates in other families.  So it takes a while to id a specimen.   P triseriata is found along the California coast and does reach a maximum size of 91 cm total length.

 

Marco Sr.

Marco Sr,

 

Thank you, yes, I processed these -- I keep some hard tissues like teeth, spines/stingers, and dermal scutes for reference, but I don't have space for whole specimens.  Standard peroxide treatment for the jaws of course, but the scutes get a 15 minute boiling water soak to denature the firmly attached connective tissues before a scrub with an old toothbrush and peroxide soak.  

 

Coming from an old collection, I can see that your specimen would have presented a daunting challenge to identify.  Thanks for taking the time and effort to post these species descriptions with excellent photos.

 

Cheers,

Eric

[sagacious]

15 hours ago, Coco said:

Sorry, I hadn't see the complete name in the title (red smilie...).

 

Coco

 

Coco,

 

No worries!  If you ever notice an error in nomenclature or an ambiguity in anything I write, I'll appreciate the opportunity to correct the error.

 

Regards,

Eric

[MarcoSr]

7 hours ago, sagacious said:

Marco Sr,

 

Thank you, yes, I processed these -- I keep some hard tissues like teeth, spines/stingers, and dermal scutes for reference, but I don't have space for whole specimens.  Standard peroxide treatment for the jaws of course, but the scutes get a 15 minute boiling water soak to denature the firmly attached connective tissues before a scrub with an old toothbrush and peroxide soak.  

 

Coming from an old collection, I can see that your specimen would have presented a daunting challenge to identify.  Thanks for taking the time and effort to post these species descriptions with excellent photos.

 

Cheers,

Eric

 

Eric

 

Again, really great job with the processing.  Do you ever try to process/dry the skin?  Most publications don't address shark/ray/skate placoid scales/dermal denticles.  At most they usually show only a line drawing of one.  From the skin I've seen they can be fairly uniform in features or vary depending on the portion of the body.  Shark placoid scales usually cover the entire body and fins.  Rays/skates can be totally without placoid scales (also called dermal denticles by some researchers), sparsely covered with them, only covered on the dorsal side, or completely covered with them like with Platyrhinoidis triseriata.  So I actually find the skin as interesting or even more interesting than the jaws and it is very difficult to find processed skin even though millions of sharks/rays./skates are caught every year for food.  Edit:  I should have said processed for scientific study versus to make boots, wallets etc.

 

Marco Sr. 

[sagacious]

On 2/25/2020 at 4:37 AM, MarcoSr said:

 

Eric

 

Again, really great job with the processing.  Do you ever try to process/dry the skin?  Most publications don't address shark/ray/skate placoid scales/dermal denticles.  At most they usually show only a line drawing of one.  From the skin I've seen they can be fairly uniform in features or vary depending on the portion of the body.  Shark placoid scales usually cover the entire body and fins.  Rays/skates can be totally without placoid scales (also called dermal denticles by some researchers), sparsely covered with them, only covered on the dorsal side, or completely covered with them like with Platyrhinoidis triseriata.  So I actually find the skin as interesting or even more interesting than the jaws and it is very difficult to find processed skin even though millions of sharks/rays./skates are caught every year for food.  Edit:  I should have said processed for scientific study versus to make boots, wallets etc.

 

Marco Sr. 

 

Marco Sr,

 

I haven't processed any chondrichthyan skin for retention as scientific specimens, so I don't have any to show, but it's not especially difficult.  I'm somewhat surprised that processed skins of scientific value, or at least dried skins, are so difficult to find.  As I mentioned above, I do occasionally find fresh dead sharks/rays/skates washed up on the coastline here, and if circumstances allow, I'll keep you I mind for samples of preserved skin.  

 

Eric

[MarcoSr]

9 hours ago, sagacious said:

 

Marco Sr,

 

I haven't processed any chondrichthyan skin for retention as scientific specimens, so I don't have any to show, but it's not especially difficult.  I'm somewhat surprised that processed skins of scientific value, or at least dried skins, are so difficult to find.  As I mentioned above, I do occasionally find fresh dead sharks/rays/skates washed up on the coastline here, and if circumstances allow, I'll keep you I mind for samples of preserved skin.  

 

Eric

 

Eric

 

Thank you.  I definitely would be interested in skin samples.  I can purchase complete taxidermy specimens of a limited number of species like the one in this post but I only buy those from old collections.  I'm OK with a sharks/rays being caught for food but not to become a taxidermy specimen for retail sale.  I can also buy a limited number of skin samples from e-bay but they tend to be very expensive and of only a few species.  I've only found two people worldwide who get heads and skin from fishmongers who dry the skins of a lot of different species.  But most of what they dry is for their own collections.

 

Marco Sr.

 

 

[Coco]

It’s not that easy to prepare selachian skins. They must be treated for preservation, and when they are dried they retract. In addition, some species have very thin skin that tears easily. These are probably the reasons why few people do it.

 

Coco

[sagacious]

5 hours ago, Coco said:

It’s not that easy to prepare selachian skins. They must be treated for preservation, and when they are dried they retract. In addition, some species have very thin skin that tears easily. These are probably the reasons why few people do it.

 

Coco

 

Coco,

 

I am quite certain you're correct about preparing entire chondrichthyan skins, especially delicate or thin ones, or where taxidermy requires a preservation of 3D shape.  Additionally, lack of market demand plays a significant part, which is really too bad, because it results in the waste of what could be a high-value product. If hagfish skins, Eptatretus sp, can be used to huge commercial success, one might think that shark skins would have similar utility.  However, the denticles/scales highlighted in this thread are also the rub, as it were, because they generally have to be removed entirely at additional cost, or sanded smooth for the product to have wide commercial application.  The processed hide market is a notoriously and chronically low-margin industry, even for the highest-demand hides, so a market for 'bat-ray leather' or similar, would probably face considerable hurdles. 

 

Many years ago, I ran a trapline and also processed furs to varying requirements -- from simply drying to tanning.  Literally from shrews to porcupines to deer.  For certain skins, I use a process that I've developed over time that removes all of the fats, oils, and volatile compounds, including water, before the skin is dried, which minimizes shrinkage and stabilizes the skin.  This process is not particularly difficult, but same as anything else in this field, and as you point out above, it must be done correctly.  

 

Eric

 

 

[MarcoSr]

25 minutes ago, sagacious said:

 

However, the denticles/scales highlighted in this thread are also the rub, as it were, because they generally have to be removed entirely at additional cost, or sanded smooth for the product to have wide commercial application.  The processed hide market is a notoriously and chronically low-margin industry, even for the highest-demand hides, so a market for 'bat-ray leather' or similar, would probably face considerable hurdles. 

 

Eric

 

 

 

Eric

 

There is a seller on e-bay actually selling what is described as sting ray leather.  Most of what he/she is selling is really expensive.  Here are a few pictures of a piece of the leather.  But I'll bet like you said there isn't much of a market for it.  You can still see the placoid scales/dermal denticles which look sanded smooth.

 

 

  

 

 

Marco Sr.

[sagacious]

10 hours ago, MarcoSr said:

 

Eric

 

There is a seller on e-bay actually selling what is described as sting ray leather.  Most of what he/she is selling is really expensive.  Here are a few pictures of a piece of the leather.  But I'll bet like you said there isn't much of a market for it.  You can still see the placoid scales/dermal denticles which look sanded smooth.

 

 

  

 

 

Marco Sr.

 

 

Marco Sr,

 

That's an excellent example of the niche market for dyed 'rayskin leather' or same or shagreen.  Processing, tanning, and dying leather of this sort for market certainly requires a huge amount of labor, and the hide is usually a bit rougher or torn around the thinner edges -- this quite nice high-quality skin has been trimmed to neaten it up for sale.  The undyed white diamond in the center is a traditional pattern seen on this type of skin.  It is still, famously, customary for Japanese swordmakers to use this material as a covering for some traditional sword/knife handles, and dyed rayskin like this has been used for all sorts of usually very high-priced high-fashion items and accessories.  Sometimes the denticles are sanded completely flat and polished so that the surface looks somewhat like smooth bone with the denticle edges forming a subtle mosaic pattern.  I believe a similar leather is sometimes made from Leucoraja fullonica, and I've seen tanned skate skins that were processed by sanding down just the sharp thorns, and leaving the less sharp denticles for texture.  Also, when there was a concerted fishery for basking sharks, it's my understanding that the skins were sometimes retained to make a particularly durable yet supple leather, although again, the rather vicious scales must be removed. 

 

Today virtually all of these leathers, whether from ray, skate, or shark, remain specialty products with easily saturated and narrow markets, or one-of-a-kind exotic designer items in high-fashion markets that depend on material rarity and uniqueness.  But even the wider leather market is in general a precariously balanced one, and the ever-increasing trend in consumption of beef, and thus (over)supply of steer skins, has lately caused the value of a tanned hide to dip below the cost of producing it.  With the enormous tonnage of rays and sharks taken by commercial fisheries, one might expect shark leather to be a banality of consumer-grade leathergoods, but as we live in a world where many sharks are killed only for their fins, sadly, this is not likely to happen soon -- regardless of market dynamics.

 

Eric