Quantcast
Channel: Science – Reefs.com
Viewing all articles
Browse latest Browse all 2258

The Evolution and Biogeography of Stonogobiops – Part 4

$
0
0

stono 35 Girdled Shrimpgoby (undescribed species) 

stono 36

Girdled Shrimpgoby. Credit: Gerry Allen

 This species is documented in Allen & Erdmann’s Reef Fishes of the East Indies, but I have failed to find a single photograph of it online. It is reported from depths of 3-20m on mud bottoms in Bali, North Sulawesi, West Papua and the Ryukyu Islands. It’s possible some of these sightings may be erroneously confusing it with other undescribed forms, especially the record from the well documented waters of Japan. This species has a number of distinctive characters: 1) The longitudinal stripes are entirely lacking, as is the diagonal stripe and spotting from the head. 2) The body has a sharply demarcated line delineating a pale anterior and a darker purple-grey posterior, centered near the origin of the anal and second dorsal fins. 3) The first dorsal fin is short, with each spine extending as a white filament well beyond the membranes.Striped-tail Shrimpgoby (undescribed species) 

stono 37

Note the eponymous striped caudal fin in this Striped-tail Shrimpgoby, from Cebu. Naoshi Suzuki

 I could find photographs of only two specimens of this apparently undescribed form, both photographed on a single dive in Cebu, Philippines. 

stono 38

A female, from same dive location as male. Note the unusual orange stripe. Credit: Naoshi Suzuki

 This species is most similar to the Girdled Shrimpgoby, but differs in several ways: 1) The caudal fin bears a series of radiating blue lines, on what appears to be a hyaline yellow background. 2) The pelvic fins are mostly clear, not white as in all other known variants. 2) The blue marginal band of the unpaired fins is absent or degenerate. In the caudal fin, only the medial edge of this band is evident. 3) Blue stripes and spots are present on the head, which are seemingly absent in the related Girdled Shrimpgoby. 4) There is no sharp color demarcation to the body, as in Girdled. Banded-fin Shrimpgoby (undescribed species) 

stono 39

Note the rounded fin in both specimens of this pair. Credit: unknown

 This is another poorly documented variant, with photographs existing from Cebu and Bali. I at first thought this was perhaps a female of the Striped Shrimpgoby, but multiple photographs exist showing paired specimens of both forms, and in both forms the first dorsal fin is similarly shaped in each sex. 

stono 40

From Okinawa. Credit: geikai_diver

 

stono 41

Juveniles from Cebu, Philippines, IDed by rounded dorsal fins.

More:

The post The Evolution and Biogeography of Stonogobiops – Part 4 appeared first on reefs.com.


Viewing all articles
Browse latest Browse all 2258

Trending Articles