Sexing Fish

[Newt]

Andy - not sure if it will help but there is an article that includes how to determine sex in the US Musky Here. Since Pike and Musky are closely related, it might apply to Pike as well. It would make sense as the shape difference in the excratory/genital area functions much the same with a female needing a hole to deposit eggs that is roughly the same size as the excratory opening (giving an oval area surronding the openings) while the male only needs to excrete milt so the opening can be smaller and you will see the charactistic "keyhole" shape of that area.

 

Fish needs to be at least 2 years old though for this method to be reliable.

 

What other fish were you interested in sexing?

[phonebush]

Offer them kinky sex and a ciggy?

You can usually tell.

Phone

[Newt]

Richard Capper:

As for sexing fish (with the exception of tench) no you cannot. Or at least no you can't easily ...

The above is pretty much true for sexually monomorphic species although even there there are exceptions. Often, with mature fish, the size of the vent will be noticibly larger/more prominent in mature females when compared to males of the species.

 

With almost all species you can use an ultrasound exam and be pretty accurate at sexing them but it does require the equipment and some expertise in anesthetizing fish safely. Probably not practical unless you are doing commercial fish raising - and especially some of the expensive and hard-to-breed tropical species.

 

However, in many species the sexes have distinct external morphological markers which makes sexing them fairly trivial.

 

OTOH since, as you pointed out, many species of fish can and do change sex in response to various environmental stresses so it may not matter very much which sex fish you start out with. Salmon do the change frequently and perch seem to respond to very low levels of estrogen in the water by changing - mostly males to females though.

[phil hackett]

Andy

Some of the points made above are pertinent ones! Granted they perhaps could have been made better. However, if you are going to continue with your intentions and it seems you are. My advice is stock with fish species that are native to the local area. Tench are not native to Scotland and do not thrive in deep acidic waters.

 

Given that the quarry is only 2 years old, I would have some concerns about its biomass and carrying capacity at this time. Waters take anything up to 20 years to full mature and as its deep, it may well take that long. By put too many fish in it in its early stages, several things may happen. The fish starve to death through lack of food (biomass) The biomass may never really establishes itself to its full potential as the fish never let it, through eating it. The fish become stunted and fail to thrive through lack of food and/or overcrowding.

 

Predator wise, they should be the last fish you introduce, as you need the prey food chain to establish itself substantially before they can thrive.

 

Draw up an action plan for the next 5+ years based on how well the water is improving year on year. If the fish are not growing don’t stock the following year as it’s likely the biomass isn’t increasing that much. More stocking will only make the problem worse not better. Most of all let the water develop naturally don’t try to force it.

 

This consultation has just cost you £1500 and the invoice is on its way by e-mail

 

Phil BSc. and to many others to list.

[anglerusmaximus]

[ 15 April 2002, 09:20 PM: Message edited by: anglerusmaximus ]

[Andy Macfarlane]

Many thanks for your many brilliant and sometimes "eccentric" replies.I do intend to keep looking at this place on a long-term basis and I hope it comes off.All it needs is care,attention,patience and the understanding that nature,if left alone for a while,will make something of value from this hole.Ta fer now.

[chevin]

[2:Its an abondoned quarry which was only given up 2 years ago..up till then it was bone dry.

 

I guess I am one of your "Dickwads" despite having been a successful fishery manager who could, at certain times of the year, determine the sex of a number of species of fish. During my management duties I tried to work with in the parameters the EA uses today, even though the Authority didn't exist in those days.

 

I noticed that in your totally unnecessary diatribe that you suggest that if the EA was interested in the water, they would have stocked it, "Years ago" and yet the pit was only flooded two years ago! Perhaps the EA has realised, as I did many years ago, that there is little point in putting fish in pits that contain no water. Being a "Dickwad" I don't know what happens to the fish if you do, but being a professional fishery manager, I do know that no one wants to fish them!

 

I would suggest that there is little point in you watching this site for any advice in the future, because I am quite sure that you have alienated those who could help you to such an extent that anything you got from them may well be counter productive. Futhermore, if I was honest, I am sure, that like a number of others, I find it a worry that you are interested in a fish's sex!

[Zinky]

Chevin,

The UK term Dickwad is a well known Northern term for what you in Oz call drongo had has a tendency to hang around with Jumbuck’s.

The Dragonbat back packer is out your way on his tour Sydney then south to Adelaide round to Perth up the Exmouth on to Darwin down to Alice Springs and now in Cairns.

Leaves Sydney in July for New Zealand.

Try this link and see some of his tour images fantastic place.

Here

Also have mate just moved to Perth very keen angler if you are in his location email me.

Stay Cool Suck Ice

[anglerusmaximus]

hope all goes well

[Gray-Catchpole]

hello andy

when i first saw this thread, i thought, there would be pleny of help and advice forthcoming, a valid question for a worthy cause, oh well i was wrong.

 

i know nothing about fishery management so i cant offer you any help on that one, but i can offer support and encouragement, you have obviously already put alot of effort into this already, go for it , and i hope it works as you wish it to