BLACKTAIL

[REEFMAN]

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[John F]

Some info on the biology of the blacktail done in southern Angola, but with relevance to the SA situation as well!

* Morphometric comparisons showed that there are not sufficient evidence for speciation between the southern Angolan and South African populations of blacktail. There was, however, sufficient morphological evidence to suggest that these populations are separate stocks.

* In southern Angola blacktail attains peak spawning in June and July. The overall sex ratio (M: F) was 1: 4.7 in the unexploited area and 50% maturity was attained at 149.5mm FL and five years.

* Blacktail in southern Angola exhibits very slow growth with the maximum age observed being 31 years. Females grew significantly faster than males, and females dominated the   larger size classes and older age classes.

* In the exploited area, the length and age frequencies were severely truncated, the maximum observed age was greatly reduced (17 years) and the sex ratio was less female biased at 1: 2.2.

* An assessment from the unexploited area revealed that the subsistence fishery had actually reduced the blacktail stock to 20% of its pristine levels.

* The study has shown that blacktail in southern Angola displays   life-history characteristics that render it susceptible to   overexploitation, even at low levels of fishing pressure.


Source: Richardson, T. J. (2010). The taxonomy, life-history and population dynamics of blacktail, Diplodus Capensis (Perciformes: Sparidae), in southern Angola. Masters thesis, Rhodes University. http://eprints.ru.ac.za/2092/

[WJ]

The only thing I know is that a Blacktail is one of the best if not the best bait for toothies in the EC.
It is a shame that they grow so slow, it will make me think twice before I send out one on the slide again.

[SAfish]

Very interesting info, JohnF. I wonder how far they go up the West African coast? 

[John F]

Well, van der Elst shows in a sketchy map that the distribution of the blacktail runs from the Somalian coast (Indian Ocean) all around southern Africa to the Mediterranean sea!!!

On the other hand, Smiths' states that the blacktail occurs from Angola to Mozambique and southern Madagascar (possibly Mauritius)... this is repeated in the fishbase front page for the blactail...

However (this is interesting!), I checked fishbase's country distribution records... the following countries are listed:

Angola (native)
Namibia (native)
South Africa (native)
Mozambique (native)
Madagascar (native)
Oman (native)
Kenya (questionable)
Tanzania (questionable)
Somalia (questionable)

So it seems it doesn't occur north of Angola. The question now is: How far up the Western Indian ocean this species goes?

[Tommo]

I caught a number of large blacktail at Flamingo Lodge in Angola on spoon, while spinning for kob. These weren't very small spoons, but the blacktail seemed far more aggressive there than the ones we get locally. Here we get them on small flies and on very small dropshot, but I have never caught one on spoon in SA waters. I don't know whether anybody else has experienced this?

[Marthin]

Tommo i think it could have something to do with the available bait.

Red bait dont move that much.....

Certain stretches of southern cape at night we caught a number of big blacktail on big fish baits that were sent out for kob and big elf from beaches.

But i havent heard of them taking big lures here.

[SAfish]

Wow Tommo, is there anything you have not caught on lure? 
The reason for my question about Angola is that I did not see any of the locals catching Blacktails in the Sumbe / Porto Ambuim area. In South Africa the Blacktail is one of the most common species but not in Angola. 

[REEFMAN]

[Plugger]

Sadly exploited on our coastline. All sizes kept and put whole ( eyes tail scale an all) into the mincer to make fish cakes. Pound for pound a nice fight.

[WalkersKiller]

Very exploited indeed, like many of our inshore reef species