Heros margaritifer rediscovered?

[Rico Morgenstern]

The latest issue of the Cichlid News Magazine contains an interesting article by Eric Hanneman about his quest for Heros margaritifer. This time he and his party searched at the pacific slope of Guatemala. They found two cichlids which they regard as possible candidates for being this mysterious species.

One, which was taken from the fish market of Santa Elena de Barillas (photo on p. 29) looks like a member of the Amphilophus citrinellus group. The fish were claimed to come from El Salvador, but the A. citrinellus group is represented neither in this country nor in Guatemala. Whatever their origin may be, they do not share more than a superficial similarity with the type of Heros margaritifer. Major differences include the blunter snout, the deeper caudal peduncle, and the position and shape of the caudal spot.

The second species they have collected I would identify as Astatheros macracanthus. The fin counts, as far as determinable from the photos, agree with that species rather than with the holotype of H. margaritifer, which has been described trice, therefore, errors in counting or misprints can be excluded. The latter has distinctly more anal (7 vs. 5) and dorsal fin spines (14-15 vs. 17) and fewer dorsal soft rays. Although some variation can be expected, it is very unlikely that the ranges for the fin counts would cover both values. Also, the holotype of H. margaritifer is much less deep-bodied with a slender caudal peduncle, and there are considerable differences in the color pattern.

One remarkable finding is, that there seem to be two "types" of A. macracanthus in the same area. The putative margaritifer is extremely deep bodied with a steeper and somewhat gibbous head profile, where as the other one, regarded by the author as the true A. macracanthus is more slender. However, the types of the species (one of which is figured in Regan, 1906-08) are very deep, too, compare also the descriptions by Günther (1864, 1868) and Regan (1905). They have been also been collected from two localities at the pacific slope of Guatemala (Huamchual and Chiapam, the latter place is not to be confused with Chiapas/Mexico!!!). That means, if the two macracanthus-like cichlids found by Hanneman (2012) are not conspecific, there is every reason to identify the deep-bodied one as the true A. macracanthus. The more slender fish agrees well with the descriptions of Heros heterodontus Vaillant & Pellegrin, 1902 and Cichlasoma evermanni Meek, 1904 (both described from Mexico). Interestingly, H. heterodontus has been maintained as a valid species until the 1970s, and the discovery of Eric Hanneman and his companions may well lead to the revalidation of one or more current synonyms of A. macracanthus. However, more observations are necessary to determine if the different forms represent two species or just reflect intraspecific variation.

In conclusion I would say that, while the mystery of Heros margaritifer remains unsolved, Hanneman's article is an invaluable contribution to the knowledge of Guatemalan cichlids.

[Piotr Koba]

So what about fish often referred to as Astatheros margaritiferum? Are all those cichlids just geographical variants of A. robertsoni from Honduras? Sorry for this possibly silly question, but I am confused

[Bas Pels]

It depends on who you ask, Piotr.

Personally I've kept them, and robertsoni and longimanus, and to me they seam to be somewhat in between robertsoni and longimanus. That makes it hard to be robertsoni, doesn't it? Still, many others think it is a robertsoni

When breeding robertsonmi have a pattern of vertical bars, while the lateral dot - which is sometimes visible - is remouved
lonigimanus have the horizontal bar, reaching from the eye to the lateral dot, highly emphasized.

the fish commonly referred to as margaritifer has both: on the fish's back the vertical bars start, but these disappear near the lateral bar which is still there - and emphasized too. The belly hardly has any black markings, but mine did have a bit of red in the throat

[Piotr Koba]

Ok, so you differentiate between fish called robertsoni Red Cheek/Jutiapa/whatever and the fish that I have seen on the EACG forum, called margaritifer, am I right? As far as I remeber you pointed out they have different breeding behaviour? Maybe instead of calling them by that mysterious name that fish should be given name on its own (as a new species), who knows?

[Bas Pels]

it would be a very large coinceidencde if they would turn out to be the elusive margiritiferium.

Mosat likely they will be described - or not, if I am found false

@ breeding behaviour, I don't thik I went into that point

My robertsoni put their egs on a large rock, just as any centrtal American would do. Te margiritiferium always put their eggs on small pebbles where the sand around them was remouved, resulting in a lot of small pits. No such pebbles, no eggs.

I think this ia a good defense agains nightly catfish predators, which will have to search all the pits one after the other - resulting in a good schance they are discovered before finding the fry.

The robertsoni never did this

[Rico Morgenstern]

Here is an interesting article on these Honduran Astatheros with beautiful photos:

http://www.dcg-online.de/encyclopedia/wp-content/uploads/2012/04/2011-05-S-109-117.pdf

The name "Astatheros margaritiferus" is expressly used provisionally in this article. Anyway, I think it's use is unwarrented. The peculiar shape of the head, the color pattern (arrangement of bars, absence of a well defined lateral blotch, shape of the caudal spot etc.) and other characters (such as the number of sensory pores on the lower jaw as mentioned by Bussing and Martin) are not shown in robertsoni-like cichlids regardless of their provenience.

There has been some confusion since R.R. Miller is said to have identified both the robertsoni-like cichlid and A. longimanus as margaritifer. In Cichlid Yearbook v.6, there is a photo by R. Wessel, which clearly shows A. longimanus, denoted as "Amphilophus margaritifer". A search at the UMMZ collection database also showed that A. longimanus is the species identified by Miller as A. margaritifer. Unfortunately, there is no publication in which Miller explains his view (at least I know of none), and it is also notknown if he did adhere to it. I find it highly unlikely that the Heros margaritifer type is just an aberrant specimen of the species known as A. longimanus. Bussing & Martin (1975) have compared large samples of both A. robertsoni and A. longimanus with data obtained from the Heros margaritfer holotype and have, in my view, demonstrated its distinctness. I still find the "hybrid theory" developed here in the forum (http://www.cichlidae.com/forum/viewtopic.php?f=4&t=8602) is still the most plausible one.

Concerning the Honduran robertsoni-like fish, I would say that there are well reasons to consider it distinct from the true A. robertsoni from Mexico, northern Guatemala and Belize. The color pattern is quite distinct, the fishes are said to attain a smaller size and there are behavioral differences as well. Bussing & Martin have grouped the Guatemala and Belize fish with the honduran form, but they had limited material from Mexico from a single drainage (Coatzacoalcos), and the life colors were evidently insufficiently kown to them.

However, still the possibility cannot be ruled out that the two fishes are connected by intermediary forms. The life colors of populations from the Caribean slope of Guatemala are not well documented. Of particular interest would be the form from the Rio Motagua drainage, which was named Cichlasoma acutum by N. Miller (1907).