In overall body shape, Anostomus species are somewhat more slender than Abramites. They also lack the broad vertical banding, having (in most cases) longitudinal stripes, and they possess a distinctively upturned mouth. Striped Anostomus is the most commonly seen species of its genus.
Members of this species are sometimes split into two subspecies: A. hypselonotus hypselonotus from the Amazon, and A. h. temetzi from the Paraguay River basin. The former is said to have its dorsal fin set farther forward and to possess a narrower caudal peduncle (the base from which the caudal fin originates). Juveniles do not have the characteristic high backs of mature specimens.
Abramites hypselonotus 88 Abudefduf saxatilis 241 Abudefduf sexfasciatus 241 Acanthurus achilles 236 Acanthurus japonicus 236 Acanthurus leucosternon 237 Acanthurus lineatus 237 Acanthurus olivaceus 237 Acanthurus pyroferus 236
The attractive patterning of these headstanders (so-called because they often rest with the head pointing downward) consists of alternating stripes of black and yellow.
Wrasses, 114, 115 Xenomysrus nigri (African knifefish), 97 Xenopoecilus, 56 Xiphophorus (platy), 48 Xiphophorus (swordtail), 48 Xiphophorus hdleri (swordtail), 48, 50, 51 Xiphophorus maculatus (platy), 48, 50 Xiphophorus vdriatus (platy), 48, 51 Zebrasoma flavescens (yellow tang), 113 Zebrasoma vdiferum (striped sailfin tang), 113
You could be forgiven for thinking that these fishes are surface dwellers, because they have long, streamlined bodies and small upturned mouths. But nothing could be further from the truth. The anostomids, sometimes referred to as “headstanders”, inhabit very fast-flowing waters in rocky stretches of rivers. They are found, head down, in narrow, vertical, rocky fissures. In the aquarium provide vertical crevices, which can be constructed from either actual rocks or plastic substitutes to lessen the weight.