Spawning and Hatching 2017

 

 

Just as we began getting used to the weather-man keep saying ‘average for the time of year’ and ‘the gardeners could do with a drop of rain’ we missed yet another golden opportunity to ‘Shut Up’… and began predicting the commencement of spawning.

Shoulders dropped, mouths widened, thermals got stuffed back in the ‘twice a year drawer’ and salad thoughts are braved; and we pencilled in April 25^th.

We then body-swerved a slight googly swerve-ball as temperatures were forecast to hit a scorching 23C in early April, so we predicted a possible early start. And, sure enough, on the hot weekend the roach did gather at the spawning boards. Then a few actually started to deposit eggs.

That was it, we thought. However, the temperature then plummeted and we were faced with events we had never encountered before.

Those few roach that had started spawning continued as the temperature fell, but the majority that hadn’t started simply backed away and held off, only to reappear two weeks later as the water temperature and day length aligned to trigger proper spawning.

So what? I hear you say…

Well, this meant that we now had roach eggs laid more than two weeks apart, which meant hatching would also be two weeks apart, so feeding brine shrimps would have to be done for more than twice as long as we like; and while the prospect of hatching roach and getting the brine shrimps into them has a huge appeal and sense of optimism leading up to it, the actual novelty of it all wears off in about twelve seconds – just kidding; it’s about a week, given the fact that the two feeds take up more than three hours of every day.

While it might all look fairly simple and straightforward, this dramatic temperature fluctuation and protracted spawning period proved to be extremely disruptive in a number of ways (but too dull to bore you guys with here). But then, we are dealing with Mother Nature, so perhaps should know by now to expect little else…

Anyway, enough of this whining…

The first quarter of the year comes hurtling at us at the speed of light, in ‘fast-forward’ mode, and while the relative warmth seeping into the lengthening days is delightfully uplifting, fuelling the sense of anticipation of kinder times, Bumble Bees and Brimstones, the sound of the first Cuckoo and arrival of the Swallows, it is also loaded with a sense of nervousness and anxiety as there is always so much to do in a fairly short period of time, all of which has to be scheduled and dealt with in order, despite what Mother Nature might throw at us.

It starts with the moving of the one year olds from the tanks to the stews and all the scrubbing and filling and preparations that follow this, then the delight of the annual fish releases into the river; a real sleeves-up, hands-on time allowing us a privileged opportunity to get the most from a unique situation and revel in a little self-indulgence, as you can see from the previous BLOG entry.

Spawning boards are placed in the river in the first week of April in preparation for the vital commencement of another cycle; an anxious time of held breath and crossed fingers; the lull before the most amazing storm.

Spawning was the usual dramatic affair, with a few locations once again showing an increase in numbers of fish attending the spawning boards. And while the stop-start spawning period was a little worrying and disruptive, it all ended up OK. However, the egg development and hatching was affected by the erratic temperatures in a way, and on a scale, we’d never seen before.

With the use of our little happy-snap underwater camera we can monitor development which helps us coordinate brine shrimp production with our hatchlings requirement for food. However, this year we were amazed at how development was slowed to almost a standstill with an unusually late bitter cold snap. Twelve days had passed and we could clearly see the little fish inside the eggs, indicating imminent hatching. The temperature then dropped through the floor and everything simply stopped. It was almost suspended animation in miniature, which lasted for days.

There was widespread scorching of delicate spring growth on plants and shrubs by an extremely late, and brittle frost. Two spawning boards with the last laid eggs were affected and we suffered a proportion of losses on these. The more developed eggs all survived and eventually hatched OK, but it was a very worrying time.

Now as we come into summer things have steadied themselves and a balance has resumed. We have tanks full of little roach which we can see growing day by day. The brine shrimp hatchery has been dismantled and chucked back in the garage and the roach are on the first stage of the specially formulated cyprinid powdered feed – so, easy-peasy times.

The sinister water boatmen are taking their toll on a few of our babies despite efforts to reduce their impact with new lids to the tanks, but on the flip side of this, our daphnia blooms in the tanks this year are like we’ve never known before. Our little roach can be seen taking full advantage of their instinct to squirt out live young every couple of weeks. So, for every Yin there is a Yang – the story of our lives.

Finally, some more great news; the small lake we had excavated at Bickton is also now fizzing with tiny roach. We floated four spawning boards in the hope that the fish we stocked would oblige and sure enough, they did. So, we now know we have yet another significant string to our ARP bow. There will have to be very strict management of this to conform to environmental regulations (some of which we helped formulate), but it’s a fantastic first step.

As usual, the rest is told through the pictures below.

Once again, thanks to everyone for the amazing help and support.



The tubercle frosted males arrived first, as usual, and began establishing territory on the spawning boards. Much of the initial chasing about is them seeing each other off. The occasional young female arrives early, but is soon forced to back off until numbers are more evenly balanced. Poor little things get utterly terrorised by the marauding males.

Then the big girls start to arrive, as you can see here, with the large female in the middle encircled by amorous frosted males.

Some of the males are surprisingly large too…

… and at a spawning board nearby, more of the same.

Then off they go.

It might simply look like a series of random explosions, but there is far more structure to it all than meets the eye. You need to be there…

It starts off quite slowly, until the females begin to arrive in greater numbers. Then the ‘explosions’ become more frequent.

And, there were some big old girls joining in again this year…

Pretty soon things were in full flow. The females would come in and get right in amongst the spawning board netting and be shrouded in ‘loving’ males as you can see here.

Our spawning boards, once again, proved to be irresistible to the roach, and even after all this time we are still amazed at the effectiveness of a bunch of netting banged to a plank and chucked in a river. I know there is more to it than that, but facts are facts….

The classic shot of a female exiting the spawning site with males in pursuit.

It might be difficult to make out from this picture, but this hopefully gives an indication of numbers of roach here. The population increase at this location has led to us placing twice as many spawning boards and replacing them more frequently to help ‘spread the load’.

This action continues for about five or six days and after a few days and a gazillion pictures, these explosions become slightly more predictable as the females are seen approaching. Sometimes there is just a flutter of attention as she glides in and away again, then there is the full-on intent as she heads into the netting on a mission to deposit her contribution to the next generation….. Mind-blowing stuff.

Fantastically explosive, and fantastic to be able to stand within a few feet and get these pictures.

This shot clearly shows two tubercle covered males rubbing against the larger smooth female to stimulate egg release. We have wondered all along if part of the attraction of our spawning boards is the texture which might be responsible for the same stimulation.

The big female rides the tangle of persistent rough males to exit.

One of the spawn-covered boards back home and in one of the tanks. One of the first days of the next three years in ARP care.

Twelve days later and hatching seems imminent – or so we thought…

After a tense and prolonged wait, hatching commences…. Phew!

When we start to see the hatchlings stuck to the underside of the spawning boards in the tank, we know it’s time to start thinking Brine Shrimps…

Not a very good shot, but the best I got of this stage this year. It shows that hatching is at full pelt and the Brine Shrimps need to be ready in a couple of days or so.

A few days later the tiny roach begin to swim freely in search of food, and we need to make sure it is there for them.

Brine Shrimp Hatchery ready to be filled and fired up.

The first full batch of shrimps ready in 48 hours. It’s always a slow start as not all the roach have hatched or detached so some are wasted at the early stage. However, it’s always better to be ready in advance than struggle to keep up.

And this is what we are looking for. Roach just a matter of a few days old full of their first feed of Brine Shrimps…… Aaaaahhhhh…..

And, yes, we just had to get you a close-up… What a bunch of saddo’s!

There is always an element of anxiety at every stage of the project, despite having done this for so many years, and here we have a shot of the first trial feed with the powdered food – interestingly and cleverly called ‘artimia replacer’….. Who’d have thought???... The way we tell if they are ready for it is to try a small feed in one tank and if they eat it and go pink, but don’t burst, then it’s OK. In fact, one of the main indicators of whether we are doing things correctly at all stages in the project is survival. The basics are; if they die, we are doing something wrong. Problem is, we can’t ask what it is we are doing wrong… Fortunately, we get more right than we get wrong.

And, yes, we had to include another close-up.

We just can’t resist a close-up…… However, one of the reasons we like to include some is that we are aware that very few folks will get to see an actual photograph of a roach so young. In fact, we have about twelve thousand we’d be happy to share with you….. No?

The powdered feed seems to take longer to go through the young roach than the Brine Shrimp, which can do so in about an hour. Another benefit of the powdered feed is that it can be fed more than twice a day using the ‘little and often’ approach. This is better for them and will aid better growth as in the wild (if they survive, and if the food is available) they will simply graze all day.

Difficult to tell from this shot so you might just have to take my word for it, but once on the powdered feed the roach can almost be seen growing each day.

One of those shots that show the numbers of fish we can have in the tanks. These are all bulging pink after a feed. Not all will survive the year in the tanks, but we have to ask how many would have survived even to this age in the wild?

Yes, we did actually take and post a picture of the daphnia bloom in the tanks and our little roach mingling with them and eating their live young. The adult daphnia are too big for our roach at this stage, but as our roach grow that changes and the adult daphnia disappear.

Water Boatmen take a number of our babies and grow with the roach, so they remain a threat for the entire time they are in the tanks together – and beyond, I dare say.

We can comfort ourselves with the fact that we hatch and grow sufficient numbers to be able to sustain a small level of losses to predation.

From ‘Mud-Pie’ to a lake fizzing with roach hatchlings. Don’t you just love it when a plan comes together. There are times within this project when pennies drop a fiver at a time, and this might just be one of those times.

We’ll leave to with some intimate roach action and the shot of the big female roach being ‘stimulated’ by frosted males at our spawning boards. What a shot. What a year so far.