Clinus agilis

Clinus agilis
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Family: Clinidae
Genus: Clinus
Species: C. agilis
Binomial name
Clinus agilis
J. L. B. Smith, 1931
Synonyms
  • Ophthalmolophus agilis (J. L. B. Smith, 1931)
  • Ophthalmolophus anne J. L. B. Smith, 1948
  • Clinus anne (J. L. B. Smith, 1948)

Clinus agilis, the Agile klipfish, is a species of clinid found in subtropical waters of the Atlantic Ocean from Namibia to South Africa where it is commonly found in estuaries and tide pools. This species can reach a maximum length of 10 centimetres (3.9 in) TL.[1]

Description

Shape:

The body is moderately elongate and slightly compressed. The dorsal profile is gently curved from the snout to the base of the forward dorsal spines, with a slight hump above the back edge of the preopercle. The snout is moderately sharp, and the mouth narrow in front, but wide at the gill openings. The cleft of the mouth is oblique with fairly thick lips. The jaws are sub-equal. There is a broad band of teeth in both jaws, with the outer row enlarged, and a curved or chevron shaped band on the vomer. Prominent tentacles above the eyes consist of flattish stalks dividing into several short simple branches at the tips. The cirri on the front nostrils are long, narrow and pointed. The dorsal fin is low, the first three spines are not elevated to form a crest, but are widely spaced. There is a notch in the fin membrane between the third and fourth spines, varying in depth, but rarely absent. The remaining spines gradually increase in length. There are clusters of 3-4 cirri at tips of the dorsal spines for about half the length of the fin. The inner pelvic ray is very small when present, but usually absent. The caudal peduncle is short.[2][3][4]

Colour:

Adults mottled dark greyish, brown or grey-green with seven or eight irregular darker red and green bars extending in some cases obliquely onto the base of the dorsal. Narrow dark band at base of caudal. Dark patch on nape. Head spotted. Dark spots on anal, pectoral and caudal, fewer on dorsal. curved dark line near base of the caudal fin. Occasionally irregular reddish blotches on dorsal (males), Reddish tinge on posterior margin of opercle. Sometimes a black spot on membrane between 1st and 2nd dorsal spines.[2] Occasional specimens have pinkish or milky ground colour with darker pink bars, or vermilion ground colour with dark brown bars. Fins dark, irregularly barred. There is a characteristic translucent area in the membrane joining the dorsal soft rays. Belly silvery white to greyish. Sprinkling of white spots over body sometimes. Head with irregular lacy pattern in body colours, or plain dark grey. There is usually a light-edged dark ocellate spot on the shoulder.[4][5][6]

Base colour pale grey to dark white, which darker vertical bars of varying width. There seem to be two main pattern varieties. The first pattern type consists of seven vertical bars. These bars are irregular, but more or less ragged on the edges. The bars can be so wide as to make the overall colour virtually black, dark brown or dark maroon. The second type consists of four thin dark vertical bars. This leaves the fish with an overall pale colour. There are always two lines radiating from the eye, a thick one towards the rear, reaching the edge of the opercle, with a thinner one down but slanted backwards. Often the dividing line is a thin dark line.[7]

Eyes are light brown, occasionally with radial lines, with dark pupil and pale iris. The lower part of the eye is white with a line extending back and becoming feinter towards the edge of the opercle.The top of the head is always dark, while the inter-orbital region is generally pale. There is generally a dark spot on the shoulder, edged in white, especially towards the rear.[7]

There is a marked similarity in appearance between Clinus brevicristatus and Clinus agilis, both in body form and colour pattern.[4] The difference taxonomically is the lower dorsal spine count in Clinus agilis, while visually the first three dorsal spines are not elevated into a small crest, with only a shallow notch between the 3rd and 4thdorsal spine, if at all. The easiest differentiation is that in Clinus agilis the dorsal fin does not have translucent patches, except at the dorsal spines.[7]

Juveniles mainly dark red-brown with similar marking. Margin of anal fin and a bar behind and below eye reddish. Adult specimens grey-green, marking much as in juveniles.[3] Juveniles white with well-defined red cross-bars.[4]

Size:

Attains 10 cm.[5] Largest specimen found 13.6 cm Total length.

Distribution

Lüderitz to Port Alfred.[5][8] Common west of Cape Point. Also in weed-beds of Knysna estuary.[9] Found in rock pools in Sea Point, and various location in False Bay, notably large numbers in Simon’s Town harbour[7]

Habitat

Common in tide pools on the coast west of the Cape and among sea-grass in the Knysna estuary.[5] Hides among weeds in pools and estuaries.[6]

All areas were on the bottom and close to sand. This contrasts with Clinus brevicristatus which have only been found on walls of reefs. Specimens have been found in virtually barren rock pools.[7]

Etymology

Agilis: from agile, referring to its behaviour.

References

  1. ↑ Froese, Rainer and Pauly, Daniel, eds. (2013). "Clinus agilis" in FishBase. April 2013 version.
  2. 1 2 3 Smith, J.L.B., 1931. New and Little Known fish from the South & Easy Coasts of Africa. Rec. Albany Mus. 4(1): 154 – 155.
  3. 1 2 Smith, J.L.B., 1947. New Clinid fishes from the south-western Cape, with notes on other fishes. Annals and Magazine of Natural History 11(14): 732 – 736.
  4. 1 2 3 4 Penrith. M.L., 1969. The Systematics of the Fishes of the Family Clinidae in South Africa. Annals of the South African Museum 55(1): 1 – 121
  5. 1 2 3 4 Smith, M.M. & Heemstra, P.C., editors. 1986. Smith's Sea Fishes. Southern Book Publishers. 1047pp.
  6. 1 2 Branch, G.M., Griffiths, C.L., Branch, M.L., & Beckley, L.E., 1994. Two Oceans - A Guide to the Marine Life of Southern Africa. David Philip Publishers: 276 – 277,
  7. 1 2 3 4 5 Zsilavecz, Guido, 2005. Coastal fishes of the Cape Peninsula and False Bay: A divers' identification guide. SURG, Cape Town. ISBN 0-620-34230-7
  8. ↑ Penrith, M.L., 1970. The Distribution of the Fishes of the Family Clinidae in Southern Africa. Annals of the South African Museum 55(3): 134 – 150
  9. ↑ Day, J.H., 1974. A guide to marine life on South African shores. A. A. Balkema: 228 – 230.
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