Analogues: (VMS3: thorax, anal fin, caudal peduncle) Larval C. hyalinus look much like larvae of the typical sand goby, but are missing the melanophores at the jaw angle and on the caudal fin. They can be similar to rare unmarked variants of the sand gobies; only the low pectoral-fin ray count would be definitive. Larval C. hyalinus have a larger eye than many of the sand goby larvae with more extensive dorsal membrane stippling, although these characters may be subtle. C. hyalinus diverge from congeners at transition when they develop an unmarked central region on the top of the head vs. a collection of spots or stripes on the others. They diverge later in transition from the two other non-sand Coryphopterus species as follows: from C. personatus by developing no rows of melanophores along the posterior dorsal quadrant (1 to 2 o'clock) of the ocular rim and from C. lipernes by developing a prominent patch of melanophores along the abdomen to the vent (vs. a simple ring around the vent). As larger recruits, C. hyalinus diverge from the former by developing extensive speckling on the posterior half of the body (vs. little to none) and from the latter by having the speckling somewhat equal above and below the lateral line (vs. mostly above the line).
Diagnosis: Modal fin-ray counts of D-VI,10 A-10 and Pect-15 indicate Coryphopterus hyalinus. The distinguishing features of later juvenile and adult C. hyalinus are mostly not present on recruits and small juveniles. (DNA)
Description: Body relatively thin, long and narrow with a large eye and a terminal mouth. Paired fins medium to long at transition, dorsal and anal-fin bases relatively short, caudal peduncle long and narrow, procurrent caudal-fin rays 7-10 (7-9 spindly). Lightly marked mostly along the lower body: melanophores on the ventral midline at the isthmus and the pelvic-fin insertion (usually streaks). Then there is a row along the anal-fin base, usually six or often seven, paired and one per side between the third and ninth element (often merged into a streak on each side). Then after a space there is a row of midline melanophores, usually seven, sometimes eight, unpaired (but often merged into a streak), extending along the caudal peduncle ending near the start of the procurrent caudal-fin rays. Internal melanophores are present at the dorsal surface of the swim bladder and around the gut near the vent (none on the head). Series of transitional larvae show development of the eye from a slightly narrowed vertical oval slightly tilted forward with a small posterior-inferior extension of the iris to round and notably larger. The extension has several surface melanophores overlying it (vs. C. glaucofraenum, comparative photograph below). Rare individuals show abnormal enlargements of this extension. There is often a prominently speckled "eyebrow" membrane over the upper half and posterior of the eyeball that appears detached from the pigmented iris below. Transitional larvae develop a scattering of iridophores between the eyes and in a stripe behind the upper eye. Melanophores start as a few scattered on top of the head developing into a loose cluster on the dorsal surface of the head behind the eye (not a stripe). Melanophores later develop in a tight group on the abdominal wall forward of the vent.
Coryphopterus hyalinus, the glass goby, is a species of goby found in the Western Atlantic Ocean from Florida and the Bahamas all the way to Central America and the Lesser Antilles.[1]
This species reaches a length of 2.5 cm (0.98 in).[2]
Coryphopterus hyalinus, the glass goby, is a species of goby found in the Western Atlantic Ocean from Florida and the Bahamas all the way to Central America and the Lesser Antilles.
This species reaches a length of 2.5 cm (0.98 in).
