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The Conus Biodiversity Website

CATALOGUE OF RECENT AND FOSSIL CONUS

  Conus striatus Linnaeus, 1758.

Range: South Africa to Red Sea, Hawaii, and French Polynesia; form floridus: W. Thailand and Andaman Is.; form subfloridus: Gulf of Mannar, Coromandel Coast and W. Thailand.

Description: Medium-sized to large, solid to heavy; forms floridus and subfloridus usually moderately large and solid. Last whorl narrowly conoid-cylindrical to conoid-cylindrical, narrowly cylindrical to cylindrical, or ventricosely conical to ovate; outline from almost evenly convex to almost straight and nearly parallel-sided centrally, generally straight just below shoulder. In form floridus, last whorl usually ovate. Aperture wider at base than near shoulder. Shoulder sharply angulate to sharply carinate. Spire of low to moderate height; outline concave to slightly convex or slightly sigmoid, stepped, less so in form subfloridus. Larval shell of about 3.5 whorls, maximum diameter 0.7-0.8 mm. First 3-5 postnuclear whorls tuberculate, following whorls angulate to sharply angulate, usually only last 1-2 whorls carinate. Teleoconch sutural ramps flat, slightly concave to concave in latest whorls, with 0-1 increasing to 3-7 spiral grooves; spiral sculpture generally weaker on latest ramps, very weak in form subfloridus. Last whorl with closely spaced, generally fine spiral ribs on basal third, finer and obsolete above, occasionally persisting to shoulder; siphonal fasciole with distinct spiral ribs except for very weak ribs in form subfloridus.

Shell Morphometry
  L 55-129 mm
     (- formfloridus 57-129 mm; - formsubfloridus 60-88 mm)
  RW 0.24-1.10 g/mm
     (L 55-111 mm; - formfloridus 0.30-0.60g/mm (L57-76 mm); - formsubfloridus 0.24-0.71 g/mm (L 60-86 mm))
  RD 0.47-0.62
     (- formfloridus 0.52- 0.59; - formsubfloridus 0.47-0.55)
  PMD 0.70-0.82
     (- formfloridus 0.69-0.76; - formsubfloridus0.71-0.79)
  RSH 0.00-0.14
     (- formfloridus 0.09-0.15; - formsubfloridus 0.06-0.13)

Typical form (Pl. 44, Figs. 18-23) with white ground colour, often suffused with shades of grey, blue, pink and violet. Last whorl with brown to black flecks, blotches, flames and axial streaks containing solid, dashed or dotted darker spiral lines and usually concentrated in 2 interrupted to solid spiral bands, above and below centre. Almost immaculate white shells intergrade with heavily patterned shells; striate colour markings often fuse into broad coalescing spiral bands or form a coarse network. Form floridus (Pl. 44, Figs. 24, 25) with white ground colour. Last whorl clouded or spirally banded with shades of pink, orange, brown, or violet. Spirally aligned brown markings occur on each side of centre, are less prominent below shoulder, and vary in number, size and shape; maculation generally sparser than in typical form. Brown spiral lines extending from siphonal fasciole to shoulder, more prominent within background clouds and bands, coarse and very dark within brown markings; spiral lines sometimes partially restricted to these markings but even in otherwise immaculate shells traceable within some ground-colour zones. Form subfloridus (Pl. 45, Figs. 1-3) with white ground colour, variably suffused with pale purple to bluish violet. Last whorl with spirally aligned yellowish to dark reddish brown spots, blotches and axial streaks within basal third, adapical third, and sometimes below shoulder. Brown markings often contain darker brown spiral lines and sometimes also wavy darker brown axial lines. Pattern usually sparse, occasionally absent. In typical form, siphonal fasciole white to cream, with variably spaced very fine brown axial lines; form subfloridus without these lines, form floridus with dotted and dashed lines on white ground. Larval whorls and about first postnuclear sutural ramp orange; in Hawaii, larval whorls pale pink before metamorphosis (Perron, 1981a); in form subfloridus, larval whorls and about first 3 postnuclear sutural ramps pale brown to pink. Following sutural ramps with yellowish to blackish brown radial lines, streaks and blotches, the latter often containing darker axial lines. Aperture white to bluish white, occasionally cream deep within; white to beige in form subfloridus; in form floridus, orange deep within.

Periostracum yellow to olive or red-brown, thin, translucent, and smooth or with fringes at shoulder; in subadults, periostracum pale yellow. Periostracum of form floridus almost identical to that of typical form with fringed shoulder; periostracum of form subfloridus also very similar but smooth at shoulder, sometimes opaque (Kohn, 1978a, as "C. gubernator").

Adult animals from Marshall Is., New Caledonia, Papua New Guinea, and Red Sea are very similar in colour pattern (Pearson, unpubl. observ., Estival, unpubl. observ., de Couet, unpubl. observ.; Richards, pers. comm., 1989; Fainzilber et al., 1992). Dorsum of foot white, with interlaced brown flecks, radial streaks and blotches that may be mottled with darker brown and be darker on lateral marginal zones; lateral pattern varies from well-separated radial markings to nearly solid brown; anterior comers and median zone almost immaculate. Sole of foot white to cream, mottled with brown. Rostrum white to beige, mottled and axially striped with brown except for distal zone. Tentacles white. Siphon white, immaculate at tip, then mottled and transversely striped with brown and/or grey to black dorsolaterally. In the Marshall Is., large subadult specimens of nearly identical shell pattern may have a body colouration similar to that of the adults or have a white foot except for brown lateral edges, while the siphon is typically patterned. Small subadult animals from Marshall Is. are white or grey to orange, often darker at anterior ends of foot, rostrum and siphon and with scattered brown to black dots (Pl. 82, Second row). In animals from Indonesia, foot orange, lightly mottled with dark brown; siphon tipped with vermilion (Kohn, unpubl. observ.). Foot, rostrum and siphon of Hawaiian specimens usually mottled tan and brown, while specimens with immaculate white shells have pale pink bodies (Kohn, 1959a; Edmonds, 1972). Philippine animals reported to have a pale yellow proboscis and the foot black dorsally and red-brown ventrally (Bergh, 1895). Form floridus reported to have a pink animal (da Motta, 1978).

Radular teeth long; adapical part with a short anterior barb opposite a long posterior barb with recurved tip, and with a short additional barb between and nearly perpendicular to the others; serration and basal spur absent (Bergh, 1895; Kohn, 1956; Marsh, 1977; James, 1980). The tooth depicted by Bandel (1984; p. 163) in Fig. 320 is that of an adult specimen, while that in Fig. 322 appears to be from a subadult specimen with the barbs not yet completely developed.

Habitat and Habits: Typical form in 1-25 m, usually in sand on coral reef, often beneath rocks and dead coral slabs (Kohn, 1959a, b, 1960; Kohn & Nybakken, 1975; Perron, 1981b; Sharabati, 1984; Reichelt & Kohn, 1985; Tirard, pers. comm., 1989). Formfloridus reported from sand bottoms in 20-40 m, form subfloridus from about 50 m. C. striatus known to feed on fishes, reported occasionally to consume molluscs; it has been observed both to ignore recently killed fishes (Kohn, 1956) and attack them the same way as living prey (Pearson, unpubl. observ.). Venom toxic to fishes, molluscs, small mammals and crabs, not affecting polychaetes (Kohn, Saunders & Wiener, 1960; Endean & Rudkin, 1965). C. textile and Pleuroploca filamentosa Röding observed to prey on C. striatus. Oviposition of the typical form beneath dead coral slabs and rocks; capsules of about 25 x 16 mm deposited in parallel rows. Egg diameter of 235-255 µm predicts a minimum pelagic period of 20-19 days; in Hawaii, diameter is 250 µm and a pelagic period of 21 days (in vitro) has been observed (Perron, 1981 a, b; Perron & Kohn, 1985).

Discussion: C. striatus is most similar to C. gubernator; for the distinctions, see the Discussion of that species. C. floridus (syn. C. chusaki) and C. subfloridus are sometimes regarded as conspecific with each other but separate from C. striatus (Richard, 1990), while other authors consider C. floridus to represent only a slight variant of C. striatus (E. A. Smith, 1884). We provisionally consider both to be ecological variants of C. striatus from deeper subtidal habitats. In W. Thailand, where all three occur sympatrically, they are very similar in shell shape, sculpture and colour pattern.

Range Map Image

C. striatus range map

This section contains verbatim reproductions of the accounts of 316 species of Conus from the Indo-Pacific region, from Manual of the Living Conidae, by Rckel, Korn and Kohn (1995). They are reproduced with the kind permission of the present publisher, Conchbooks.

All plates and figures referred to in the text are also in Rckel, Korn & Kohn, 1995. Manual of the Living Conidae Vol. 1: Indo-Pacific Region.

The range maps have been modified so that each species account has it own map, rather than one map that showed the ranges of several species in the original work. This was necessary because each species account is on a separate page on the website and not confined to the order of accounts in the book.

 

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