Paracentropyge is a small genus with three species. Over the years, the placement of P. venusta as well as P. multifasciata have been in rather constant shuffle, moving back and forth between this as well as Centropyge. Allen and Erdmann’s book on fishes of the east indies places the two back in Centropyge. P. boylei remains untouched. For standardisation, we will be still be using Paracentropyge in this article.
Of the three species, P. multifasciata has the widest range and spans much of the western and eastern Pacific, and as far as aquarium exports are concern, comes out of Indonesia, Philippines, Vanuatu and the Marshall Islands. P. boylei is found in the Cook Islands, and recently in other parts of the Southern Pacific as well. P. venusta is restricted to the Philippines and Japan, and is also the only member of its genus to lack any vertical striping.
P. venusta is bicolored purple-blue and yellow, with a triangular face mask that covers the eye. What is interesting about this species is its extremely variable nature. Unlike the cookie cutter P. boylei and P. multifasciata, P. venusta has a spectrum of variations and forms.
After looking at numerous specimens as well as photos of P. venusta, we started noticing a trend. As volatile as the designs may be, the variability of P. venusta mainly depends on two factors. The variability of their crown, and the amount of blue or yellow the individual possesses. These two main variations can differ from individual fish and can come in any number of permutations.
Let us first look at the crown variability. In a standard P. venusta as in the picture headlining this article, the blue mask is divided from the rest of the body by a sliver of yellow that touches the anterior portion of the nape, proximal to the dorsal fin. This creates a yellow triangle in the opposite direction of the mask. For all intent and purposes, let us refer to this as the “crown”.
In the rather badly drawn illustration above, you can see that there are three main types of crown pattern. Again, each type is subject to individual variation even amongst the fish, but the standard template can usually be traced back to these three types.
– Type A crowns are as mentioned, the standard common type. The blue mask is separated from the rest of the body by a diagonally oblique yellow triangle. This yellow then travels down to the anal fin. The way the yellow travels toward the anal fin can vary, and in the pictorial hand-drawn illustration above, you can see it takes two general routes toward the anal fin. Either it travels down diagonally, or horizontally across. Some specimens may have the yellow and blue segregation totally blurred and smudged out such that there are no clear demarkations.
However the crown pattern for type A regardless of the yellow and blue body markings are the same. That is, the blue mask and blue body is separated by a sliver of yellow.
– Type B crowns are less common, but are not rare. In specimens with this form of crown variation, the gap between the mask and the body never meet due to the widening of the yellow divider. As such, the yellow between the crown and the blue body markings take on a more rectangular shape instead of triangular. In the specimen above, this is very clear.
– In the last crown variation type C, the blue mask always meets the blue portion of the body. In essence this variation is the reverse of type B. The yellow never meets the dorsal region and is very much reduced to usually, just behind the eye. The specimen above shows a typical fish with type C crown markings, and this usually makes the fish look much bluer than normal.
You’ll notice that even with the three main crown patterns, every specimen of P. venusta differs vastly. This is due to the second variable factor, which is the extent of blue or yellow on the body.
Normally, P. venusta has a rather equal part blue and yellow coloration. The dorsal and tail region being blue, and the chest and lower half, yellow. The yellow and blue demarkation as mentioned before, can differ in either being drawn out horizontally, or downward diagonally. The specimen above is a good example showing the yellow portion drawn out horizontally. Take note of the additional yellow spot above the crown, which shows just how volatile they can be in terms of patterning. The specimen can to a certain extent be still classified as type A, although not in the strictest sense.
Here we have two more examples of type C P. venusta with varying amounts of yellow. Because the yellow is much reduced at the head region, the blue is allowed to continue from the mask to the rest of the body. Type C P. venusta are therefore always much bluer in appearance compared to the other types. But even so, the amount of blue within this type group itself is variable. Compare these two with the image of the same type P. venusta above.
Now these pair of spawning type C P. venusta also exhibit the same crown types as the ones previously mentioned. However the extent of blue is very much more pronounced as compared to the ones formally mentioned. It is possible that these fishes change their coloration as they grow, so depending on which life stage they are currently at, they may appear more or less blue.
An even more exaggerated example of a type C P. venusta is shown above, where the blue markings practically overwhelms the entire top half of the fish. In specimens like these, crown patterns are no longer existent and the fish takes on a bicolour appearance. Large adult fishes are usually more prone to such extensive blue markings as compared to juveniles.
On the extreme end, high yellow P. venusta also occur. These are usually aberrations and a crown type is difficult to place. In such specimens, the blue mask is usually reduced to an irregular blotch or sometimes, very rarely, totally non existent. In those such as the one above with a reduced mask, a type B crown type may be the closet fit, where the yellow extends dramatically and extensively to cover much of the body.
In these two examples we can see again the extensive high yellow markings. In both specimens, the mask is again aberrated and reduced to a strip.
The photo above, poor in quality as it may be, is one of very few examples where a mask is totally absent, and the fish is extensively yellow. Such specimens are very rare and this individual from toismarine has remained like this for several months. In specimens like this, a crown type allocation is obviously non applicable.
This specimen above borders between having a mask and not having one. The smudge above the eye and extensive yellow is just another extreme variation for the species. Unsurprisingly, intermediates for the crown types exist, but these appear mostly in very small juvenile fish. These two below for example, show a mix between two types of crown patterns.
The one on the left has the first two dorsal spines coloured yellow and while the blue mask and body doesn’t touch, it’s not really wide enough to consider this a type B specimen. It intermediates between A and B. The specimen on the right has the yellow divider almost separating the blue mask and the body, but not quite. As such it is an intermediate between B and C. However seeing as these are juveniles, their pattern will change as they grow and may eventually put them in a more standard looking type.
The “type” systems of crown patterns are purely colloquial and just used as an easier way to refer to the variations. These are just observations made on our own based on specimens we have seen on the internet as well as in person. It is indeed very interesting why P. venusta is subjected to such extreme variations while the other two members of its genus are not.