Thresher Shark

This afternoon, November 10, 1999, a juvenile male thresher shark, Alopias vulpinus, was landed in Guernsey. It was caught in gill nets about one mile south of Guernsey in about 20 metres (60 feet) of water.  The shark contained remains of clupeoid fish in its mouth (probably sprats).

The following measurements were made.
Total length    175 cm
Fork length    98 cm
Tail length (from precaudal pit to tip) 92 cm
Snout tip to origin of D1   42 cm
Snout tip to precaudal pit  86 cm
Rear  of D1 attachment to precaudal pit 32 cm
D1 rear attachment to origin D2  24 cm
D1 height    11.5 cm
Girth at origin of pectoral fins  54.5 cm
Girth at origin of D1   63 cm
Girth at origin of pelvic fins  53 cm
Interorbital distance (convex)  9.8 cm

The thresher shark was caught along with sea Bass, Red Mullet, pollack, plaice, a Seahorse (Hippocampus hippocampus) and a small Gilthead Sea Bream (Sparus aurata).

I will have the whole and gutted weight for the thresher shark shortly.  The viscera are being saved for me. (I will have the viscera this evening if anyone wants them for study.)

Total weight:   16.55 kg

The Thresher Shark was caught about a third of a mile offshore.  The capture was at 49° 24.8' N and 2° 36.85' W near rocks called Les Lieuses.

 The viscera weighed 1759 grams. Gutted weight this morning was confirmed as 14.80 kilograms.  I spoke to the fisherman again this morning.  The whole weight appears to have been 16.5 kg and not 16.05 kg.  It is possible that the whole weight was 16.55 kgs. This would add up with the viscera weight (16.55 - 1.75 = 14.80 kg.).  I weighed two liver lobes (1013 grams), the stomach and spiral valve both full and empty if you are interested in the information.  There were a couple of organs I couldn't identify.  I will have photographs of these organs and can email them to you when they are developed if you can help me identify them.  One of the organs looks like liver but it is a small two-lobed affair that weighs 36 grams.  The other organ I couldn't identify is long and convoluted and weighs 19 grams.  It is a dark reddish colour.  I will have to look at the photographs when they are developed to remember what it was attached to.  I saved visceral tissue in ethanol for future studies if necessary.
 

Best Wishes,
Yours sincerely,
Richard
Richard Lord
Guernsey GY1 1BQ
Great Britain

Email:  fishinfo@guernsey.net


Alopias vulpinus
I can assure you that they are far from being rare in the inshore waters of the central English Channel, at least up as far as Selsey Bill, Sussex. & possibly further east.
They are seen jumping out of the water on a regular basis South of the Isle of Wight.
They do seem to be solitary as opposed to Porbeagle.

The normal average weight seems to be between 150 & 200 lb with small juveniles up to 70 lb not uncommon.
Two such juveniles were caught & released by an angling boat last week & I tagged & released a 200 lb female this weekend.

Regards
Alan Deeming

gknwae.co.uk">Alan Deeming