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gingerbeer

Hot Topic Friday 16 January 2015:"Wild Caught Fish"

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it does surprise me the uniformity of a lot of wild caughts .

Why does this surprise you? Selection pressures are more uniform in the wild and there is a larger, therefore more stable gene pool.

Anyway, my response to the topic statement is as follows:

*In terms of the phrasing of the statement: Of course you can claim that the fish are wild caught. But can you substantiate this claim without papers?

*Personal opinion: I don't care whether or not any fish is wild caught.

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The only fish I know, you can tell are "Wild caught" are apistogramma's with random black spots....a benign condition that many Wild caught apisto's have

and maybe some natives....with parasites imbedded in their skin

Otherwise it's just trust....

"papers" wouldn't cut it with me...

Edited by Rod
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The only fish I know, you can tell are "Wild caught" are apistogramma's with random black spots....a benign condition that many Wild caught apisto's have

and maybe some natives....with parasites imbedded in their skin

Otherwise it's just trust....

"papers" wouldn't cut it with me...

Interesting.

Same thing in Africans, we call 'em "lake spots".

Digenetic trematodes that prob require snails and birds to progress through life cycle.

Common aquarium name is actually "black spot" but shares it with other diseases.

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The only fish I know, you can tell are "Wild caught" are apistogramma's with random black spots....a benign condition that many Wild caught apisto's have

and maybe some natives....with parasites imbedded in their skin

Otherwise it's just trust....

"papers" wouldn't cut it with me...

I've come across the same condition with wild bettas.

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microchips means nothing.... i know several people who can reprogram/install/scramble them.

other factors to render them useless; they grow out / cause infections / death.

they maybe a thing of the future..... however as far as trust is concerned with "authenticating a wild caught" is no different from a piece of paper.

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So the black spots, they are often called grubs.

Black, white or yellow.

blackspot1_zps0d41439e.jpg

blackspot2_zps9df9786b.jpg

blackspot3_zps3fd8b0bf.jpg

https://books.google.com.au/books?id=PPW_AwAAQBAJ&pg=PA353&lpg=PA353&dq#v=onepage&q&f=false

Mongenetic Trematodes

This is a group of trematodes which complete their entire life cycle on the host. The adults attach to the host by a haptor or opishaptor which is a specially adapted structure on the posterior end of the parasite. This organ has hooks which allow the parasite to attach firmly to the host fish. These parasites usually cause minimal damage to fish, but will infest the skin, fin and gills of pond fishes. Severe infestations may be responsible for poor respiration and/or emaciation. The two most common monogenetic trematodes include: Dactylogyrus and Gyrodactylus.

Dactylogyrus sp: This parasite is approximately 0.2 to 0.5 mm in length, reaching a maximum length of 2.0 mm. It has seven pairs of marginal hooks and usually one pair of median hooks on the opishaptor. The dactylogrids have two to four pigmented spots (known as “eyes” or “eye spots”) in the anterior fourth of the body. All dactylogrids are oviparous with no uterus (photo).

Gyrodactylus sp: This parasite is smaller, rarely reaching a maximum length of over 0.4 mm. All species are viviparous with one to three daughter generations being observable in the V-shaped uterus. This parasite is more commonly found on the skin and less commonly present in the gills, although severe infestation will have both organs affected.

Digenetic Trematodes

This group of parasites has a complex life cycle with several successive larval generations, alternating sexual and asexual generations and changes of hosts to develop into the adult in its primary host. The life cycles of trematodes involving fishes may either use fishes as the primary hosts or as intermediate hosts. Adult trematodes may infest the intestine or gall bladder of fishes. A few of the more common digenetic trematodes are listed below.

Diplostomum spathaceum: The life cycle of this parasite begins as an adult trematode in the intestine of gulls or other fish-eating birds. The body of the adult is 0.3-0.5 cm in length and distinctly divided into a flattened anterior forebody and a cylindrical and narrower hindbody. Eggs are shed and passed in the feces of the bird to the water. The eggs hatch in approximately 21 days into free-swimming ciliated miracidia. The miracidia infest aquatic snails as the first intermediate host by penetration of the snail’s hepatopancreas. The miracidia then become a mother sporocyst, followed by one or more daughter sporocysts. Each daughter sporocyst produces many cercariae which are released into the water. These cercariae seek a second intermediate host by penetrating the fins, skin, gills or cornea of small fishes. Primary host fish which ingest the initially infected fish (second intermediate host) become infected and the life-cycle is completed when the host fish are ingested by fish-eating birds.

Posthodiplostomum minimum: This trematode has several synonyms including: Neodiplostomum minimum, Neodiplostomum orchilongum and Postodiplostomum orchilongum. The life cycle of this trematode is very similar to that of D. spathaceum above, although, infectivity of cercariae to fishes lasts no more than 24 hours after release from the snail. Each cercaria actively raises a scale and enters under the scale pocket, causing irritation to the fish. Blood, congestion and hemorrhage occur at the bases of fins or other places of cercarial penetration. The trematodes migrate from the point of entry to visceral organs of the fishes, usually within one to three hours after penetration. Metacercariae are located in any organ of the fishes’ body, but are generally more numerous in the liver, kidney, heart, spleen and other organs of abdominal viscera. With many of the digenetic trematodes, the metacercariae within the skin results in increased melanin deposition, hence the term “black spot disease”. (Photo demonstrates "black grub" in the fin of an affected fish). Visible white or yellow spots in the visceral organs, usually no larger than 1 mm in diameter are often referred to as “white grubs” (photo) or “yellow grubs” (photomicrograph demonstrates "yellow grub" in muscle tissue of affected fish) and could be caused by several trematode species. Diagnosis of digenetic trematode infections is dependent upon identification of the genus and species of the trematode within infected fish.

Parasitic Diseases of the Fish

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Personally I prefer locally bred, quality fish. They are better adapted to our local water, tend to have less health issues and live longer.

This could easily be a topic in itself. I tend to doubt that fish "adapt" to local water in just a few generations. I do think that local fish have not gone through as many traumatic events in traveling.

I tend to believe in getting the best, that may not be the claimed F1 specimen, or German specimen. I am also reminded again by the current convict thread, tow fish that are average of different blood lines can give a great result.

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