"Paradox lost" : skeletal ontogeny of Indostomus paradoxus and its significance for the phylogenetic relationships of Indostomidae (Teleostei, Gasterosteiformes)

Title Variants

Alternative: Skeletal ontogeny of Indostomus

Related Titles

Series: American Museum novitates, no. 3383

By

Britz, Ralf, 1964-

Johnson, G. David

Type

Book

Material

Published material

Publication info

New York, NY American Museum of Natural History c2002

Notes

Title from caption.

"December 27, 2002."

Specimens of Indostomus paradoxus first discovered in Lake Indawgyi, Upper Burma, in 1926.

On the basis of an ontogenetic series of Indostomus paradoxus, we test characters that have been proposed for the phylogenetic placement of this enigmatic taxon. Contrary to previous authors, we found that the body armor of Indostomus differs from that of syngnathoids greatly and it closely resembles that of gasterosteoids in many unique details. The body plates originate from two different sources, that is, the endoskeleton (proximal-middle radials of dorsal and anal fin, neural and hemal spines, pelvic cartilages) and the exoskeleton (postcleithra, lateral body plates, sternal plate). The median bone in the ethmoid region develops from two centers and most likely represents the nasal bones that fuse during ontogeny with each other and with the vomer. Identity of the opercular bones is clarified, and it is demonstrated that Indostomus has an interopercle. The single pterygoid bone is the ectopterygoid. A parietal is lacking. There is only one cartilaginously preformed hypural element in the caudal fin. There is no parhypural, but a similar structure, termed the pseudoparhypural by us, develops as membranous outgrowths of the single hypural and the ural centrum. The pectoral radial plate fuses to the scapulocoracoid cartilage, and the pectoral radials ossify within that fused plate without prior fragmentation of the plate into individual radials, being specializations of the pectoral girdle that we think to be shared with all gasterosteoids. Indostomus shares with other gasterosteiforms the modification of the tripartite occipital condyle into an articulation of the basioccipital and the first centrum through loss of the articulation between exoccipitals and the first centrum in all developmental stages. Indostomus lacks distal radials in all pterygiophores supporting fin spines at all developmental stages, a character shared with other gasterosteiforms, mastacembelids, and probably other smegmamorphs. We conclude that Indostomus is a gasterosteoid gasterosteiform.

Subjects

Bones , Burma, Upper , Classification , Development , Fishes , Gasterosteiformes , Indostomus paradoxus , Phylogeny

Call Number

QL1 .A436 no.3383 2002

Language

English

Identifiers

DOI: https://doi.org/10.1206/0003-0082(2002)383<0001:PLSOOI>2.0.CO;2
OCLC: 51301884