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Topwater Caranx Ignobilis: Giant Trevally (GT) => Reports & Expeditions => Topic started by: Anton_Jordan on April 30, 2010, 07:04:56 PM

Title: Calculating Size by length
Post by: Anton_Jordan on April 30, 2010, 07:04:56 PM

Hi guys,
Recently did a trip to Maldives and managed to land a few nice GTs on poppers.. most were around the 80cm mark.. but biggest was 117cm.
anyone able to give a more acurate mass as I didnt have a scale with me? forgot to measure the girth
all fish were successfully released to fight another day.

thanks in adv.

Title: Re: Calculating Size by length
Post by: Luke Wyrsta on April 30, 2010, 10:15:36 PM

Quote from: Anton Jordan on April 30, 2010, 07:04:56 PM

Hi guys,
Recently did a trip to Maldives and managed to land a few nice GTs on poppers.. most were around the 80cm mark.. but biggest was 117cm.
anyone able to give a more acurate mass as I didnt have a scale with me? forgot to measure the girth
all fish were successfully released to fight another day.

thanks in adv.

GTs come in many sizes and shapes - fish of equal weight can vary greatly in length and girth.

You cannot gauge/formula a GTs weight solely on length, without a girth measurement.

Title: Re: Calculating Size by length
Post by: Jay Burgess on April 30, 2010, 10:55:01 PM

Are your lengths fork length or total length?

Title: Re: Calculating Size by length
Post by: Anton_Jordan on May 01, 2010, 03:36:39 PM

Length is fork length... from tip of mouth to centre of fork in tail.
I realize weight will differ from fish to fish.. but as I am not that experienced I find it quite difficult to judge the weight... therefore I wanted to know whether my assessment of between 17-20kg is more or less within the ballpark figure.. 
many thanks



 

Title: Re: Calculating Size by length
Post by: Stephen Polzin on May 02, 2010, 04:37:51 PM

I'll say 80cm 12-14kg, 117cm 25-30. 

Title: Re: Calculating Size by length
Post by: Jon Li on May 03, 2010, 04:06:48 AM

I second Luke's , without the girth measurement , one can't remotely predict the weight of any fish .

Jon . 

Title: Re: Calculating Size by length
Post by: Callan Wallace on May 03, 2010, 05:04:28 AM

I found plenty of reference on the web.

Length x Girth Squared / 800 = Weight

Multiply the girth by itself.
Then multiply the length with the answer above.
Divide this new answer by 800 and you should have your estimated weight in pounds.

Close enough I would assume.
Cheers

Title: Re: Calculating Size by length
Post by: Luke Wyrsta on May 03, 2010, 08:54:36 AM

Quote from: Callan Wallace on May 03, 2010, 05:04:28 AM

I found plenty of reference on the web.

Length x Girth Squared / 800 = Weight

Multiply the girth by itself.
Then multiply the length with the answer above.
Divide this new answer by 800 and you should have your estimated weight in pounds.

Close enough I would assume.
Cheers

He doesn't have girth measurement.

Title: Re: Calculating Size by length
Post by: jay currie on May 03, 2010, 06:28:53 PM

Hey a fish was caught on last trip was 44 inch (111.7cm)long and weighed 28kg and it wasnt a very fat fish. But you will never know for sure how much yours weighed so I would just estamate around 30kg and just be happy with a great fish, I think way to much energy and time is wasted with people argueing over weights and sizes of fish and in the end they forget it is all for fun and forget to appriecate a good catch weather the estemated size is exact or not, I find it really takes away from the whole experience.

Title: Re: Calculating Size by length
Post by: Callan Wallace on May 03, 2010, 07:30:43 PM

I have to agree with you Jay. Any day out there sure beats a day at work.