Larval attachment organs (LAOs) are unicellular or multicellular organs that allow larvae to adhere to a substrate before yolk-sac absorption and the free-swimming stage.This study documents the LAO of tropical gar, Atractosteus tropicus, using a combination of scanning electron microscopy and light microscopy. It is shown that the LAO of A. tropicus is a super-organ surrounded by a wall and containing at its centre many smaller multicellular organ units, each comprised of attachment and support cells.Attachment cells are secretory and house large vacuoles filled with a glycoprotein. At hatching, the super-organ is well developed and occupies almost the entire anteroventral surface of the head. During subsequent development, the smaller individual units begin to regress, until at 6 days post-hatching the super-organ and its individual units are no longer visible.

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The native range of Ophichthys cuchia includes part of Bangladesh, Bhutan, India, Myanmar, and Nepal. Ophichthys cuchia has also been collected within six states in the USA (Louisiana, Maryland, Michigan, New Jersey, New York, and Pennsylvania) and an established invasive population exists in New Orleans (Louisiana). We provide the first record of O. cuchia from Texas and the second report of an established non-native population in the USA based on 26 museum vouchered specimens collected from a series of urban ponds within the Houston metro area (Fort Bend Co.).

Cyprinella panarcys is considered to be endemic to the upper Río Conchos drainage of Mexico. A single individual of C. panarcys was collected from the Rio Grande along the USA–Mexico international border (Presidio Co., Texas) in April 2018. This is the first record of C. panarcys from outside of the Río Conchos and the first record from the USA. A brief description of the external morphology of the individual collected is provided along with an updated distribution map for the species.

The eyes of teleostean fishes typically exhibit two ossifications, the anterior and posterior sclerotics, both associated with the scleral cartilage. The West African Denticle herring Denticeps clupeoides has three scleral ossifications, including the typical two associated with the scleral cartilage (anterior and posterior sclerotic) and a third ossification (Di Dario's ossicle), spatially separated from the scleral cartilage and located within the anteromedial wall of the sclera. The medial rectus muscle inserts on the medial surface of Di Dario's ossicle, suggesting that this third sclerotic may play a role in forward rotation of the eye in this surface feeding fish.