2017-11-26 Amazonas

cm total length) than those caught in black waters. The

animals from clear water also have comparatively larger

fins. Pseudomugil ivantsoffi specimens also vary in fin col-

oration. Dominant males have a red caudal and caudal

peduncle and yellow dorsal and anal fins. In some of my

males from the same population, the red extends into the

dorsal fins and also the posterior part of the anal fin. The

transitions in my males are fluid, but the purely yellow

animals dominate.

We know of different color varieties in P. pellucidus

and P. novaeguineae as well, but some forms attributed to

P. pellucidus may actually be different species. I personal-

ly know of three distinctly different forms, all of which

have a black longitudinal stripe bordered by a yellow

longitudinal line.

In the Sungai Kamora drainage, especially in the

immediate vicinity of Timika, there are fish that I call

P. pellucidus “Timika.” The first dorsal fin in this form

may be trimmed in black or black and red, and the anal

fin has a black and yellow or black and white stripe. In

most specimens the second dorsal fin is yellow, in some

it is white, and in a very few it is red. A second form,

which so far I have seen only in a clearwater stream in

the drainage of the Sungai Mimika (the river west of the

Mayak), has red dorsal fins and a black, red, and yellow–

striped anal fin with varying intensity. I call this form P.

pellucidus “Mimika.”

And during our January 2015 visit, when we ventured

quite a bit further west to the Sungai Kiura, we found a

form with a black and yellow anal fin that was otherwise

mainly black with a little yellow pigment. These fish are

spread throughout the Kiura River in clear water and

are somewhat taller and more robust. In 2017 we finally

reached the Sungai Kabur, some 62 miles (100 km) west

of Timika. This, and the Sungai Putih east of it, are white-

water rivers in which we found no blue-eyes. However, in

their clearwater tributaries we encountered yet another P.

pellucidus form, which I call P. pellucidus “Kiura."

Pseudomugil novaeguineae is quite rare west of the Sun-

gai Ajkwa. I only found this species at a single location

near Timika. In addition to monotonous gray specimens,

my friend Neil Woodward and I collected specimens with

bright red caudal peduncles in 2013. Apparently, there are

also different color varieties in P. novaguineae.

As far as I know, a new representative from this

group has only been exported to Taiwan. These animals

AMAZONAS

Pseudomugil sp. “Red Fin” may also have

red pigment in the relatively large anal fin.

A large (2.8 inches/7 cm) male Pseudomugil ivantsoffi

from a clearwater stream in the Mimika Regency.

TOP: F. WANG; MIDDLE: H.-G. EVERS