ID Column
Guam Shell News Vol. 1, No. 4
Oct-Dec 1979
Left & Center: Lambis scorpio Linné, 1768. Right: Vexillum mirabile A. Adams, 1853.
Lambis scorpio Linné, 1768. One of five species of spider shells which are found on Guam. A large shell (4 to 5 inches) usually found on coral reefs in rubble or sand. Uncommon on Guam and mainly limited in Apra Harbor. The dark purple aperture, lined with white, and knuckle like structures on the fingers make this species quite easy to identify.
Vexillum mirabile (A.Adams, 1853). A large (48mm) costellaria which is found in deep water (90 feet) around Guam. Rare! A few specimens have been found in 90-110 feet in shallow sand pockets near Orote Point, Guam. Two color forms are found here. The typical white shell with dark brown spots and white shells (as pictured) with bright red markings. These shells are sometimes referred to as Vexillum angulosum Kuster, 1839.
Left & Center: Lambis lambis Linné, 1758. Right: Vexillum (Costellaria) xenium Pilsbry, 1921.
Lambis lambis Linné, 1758. The most common spider conch on Guam. The species is large, up to 6 inches. This particular speciman is a dwarf shell 90mm in length. These dwarfs are rare on Guam. These shells are found in all types of habitat but seem to be very abundant on the reefs of Apra Harbor.
Vexillum (Costellaria) xenium Pilsbry, 1921. Another deep water species found below 90 feet in shallow sand pockets. This species reaches a lengh of 1¾ inches. It is circled with fine interrupted lines and large square brown blotches at the shoulders. This is a new range extension previously being recorded only from Hawaii. Rare on Guam.
Left: Strombus (Canarium) haemostoma Sowerby, 1842. Center: Strombus (Canarium) wilsonorum Abbott, 1967. Right: Vexillum (Costellaria) sulense Adams & Reeve, 1850.
Strombus (Canarium) haemastoma Sowerby, 1842. A small white shell with a bright red stain on the columella. A rare shell found in shallow sand pockets on reefs from 35 to 55 feet. (More about this species in the ID Section)
Strombus wilsonorum (Abbott, 1967). An uncommon Guam strombus. Because of this species close resemblence to Strombus maculatus and Strombus microurceus (both common species on Guam) it has often been overlooked. This species has a brown blotch at the top and bottom of the columella. It is often found in colonies in shallow sand pockets from shallow water to 60 feet.
Costellaria suluense Adams & Reeve, 1850. Known only from a single adult specimen (17mm) found by Olly McCarslano. This species has a wide range from the Philippines to New Guinea, east to Tahiti and now a new range extension north to Guam.
Left & Center: Maculotriton sculptile Reeve, 1844. Right: Conus leopardus Röding, 1798.
Maculotriton sculptile Reeve, 1844. A rare species which has been placed in the murex subfamily Thaidinae. Little is known about this 15mm shell. Often confused with the common Guam Maculotriton serriale. The deep pits at the suture and strange open grove on the lower body whorl separate it from Maculotriton serriale.
Conus leopardus Röding, 1798. A large (to 6 inches) cone. Not uncommon in some areas especially near Cocos Island. Usually in sand with a fairly thick periostracum.
Left: Aspella producta Pease, 1861. Center: Aspella platylaevis Radwin & D'Attilio. Right: Conus legatus Lamark, 1810.
Aspella producta Pease, 1861. One of only two species belonging to this genus, found here on Guam. This murex species is usually worn and is rarely found here. Most specimens found on Guam have been worn, stained brown and the protroconch was missing. Found in rubble.
Aspella platylaevis Radwin & D’Attilio, 1976. A small (10mm) species. This shell has been pictured in several books as Aspella anceps but in Radwin & D’Attilio’s murex book it was felt that A. anceps should be treated as a nomum dubium as there was no drawing with Lamark’s original description. Therefore this species is now recognized by the new name A. platylaevis. Spade shaped and razor thin it is often found wedged in coral rubble in Apra Harbor. Common in some areas of Apra Harbor.
Conus legatus Lamark, 1810. One of Guam’s most beautiful tent cones. Growing to approximately 1-3/4 inches. A beautiful pink with small distinct tent like patterns. Found beneath rubble and coral in silt from 15 feet down to 90 feet. Small specimens are faily common but the largest cones are uncommon.
Left: Oliva paxillus Reeve, 1850. Center: Oliva panniculata Duclos, 1835. Right: Conus aureus Hwass, 1792.
Oliva paxillus Reeve, 1850. A small ½ inch species found commonly in clean white sand, usually near terraced coral reefs just behind the reef front. Sometimes almost black in color from sand in deeper water.
Oliva panniculata Duclos, 1835. A slender species closely resembling the previously figured olive. Sometimes found in deeper water with Oliva paxillus. This species is found in deeper water from 35 feet down to 90 feet in clean white sand. It comes in various colors including white, brown, and black.
Conus aureus Hwass, 1792. A rare Guam shell. This species is rarely found alive but is more commonly known from beach specimens in Apra Harbor. It lives deep within coral rubble making it extremely hard to collect alive. Quite a few isolated specimens have been taken on the coral reefs in Apra Harbor. It grows to almost 3 inches.
Left: Imbricaria punctata Swainson, 1821. Center: Imbricaria conovula Quoy & Gaimard, 1833. Right: Iredalea pygmaea Dunker, 1860.
Imbricaria punctata Swainson, 1821. On Guam a groun of cone like miters can be found in shallow water. This is one of those miters. Rather dull in color, this is undoubtedly one of Guam’s most abundant shell. It grows to 1/2 inch.
Imbricaria conovula Quoy & Gaimard, 1833. Very much like the previous species except for the black spot at the extreme tip of the columella. Abundant on the flat coral reefs in shallow water. Usually note found with Imbricaria punctata. Both these species can be found in shallow sand pockets from 35 feet to 75 feet.
Iredalea pygmaea Dunker, 1860. This is a member of the turrid shell family. A small (6mm) shell found commonly in shallow sand pockets in depths from 6 inches down to 60 feet. It lacks the notch above the aperture which is usually associated with turrids. It often has the protoconch broken off especially in shall waters.
Left: Imbricaria vanikoroensis Quoy & Gaimard, 1833. Center: Imbricaria olivaeformis Swainson, 1821. Right: Daphnella delicata Reeve, 1846.
Imbricaria vanikoroensis Quoy & Gaimard, 1833. Another cone like species uncommon in shallow water becoming more common in deeper water. Usually in shallow sand pockets. White with brown nebulous spots.
Imbricaria olivaeformis Swainson, 1821. The olive-like miter. A shining yellow shell with a dark blotch at the tip of the collumella. Common in sand from 6 inches to 60 feet.
Daphnella delicata Reeve, 1846. An uncommon turrid found in rubble from 6 inches to 90 feet. Creamy white with brown flame like markings. A delicate thin shelled species with the characteristic siphonal notch of turrids.
Left: Imbricaria conularis Lamark, 1811. Center: Vexillum (Pusia) exquisitum (Garrett, 1873). Right: Lienardia rubida Hinds, 1844.
Imbricaria conularis Lamark, 1811. A smooth shiny cone-like species abundant in shallow water in sand. As the other 4 Imbricaria species, this shell comes out at night, crawling around on top of the sand.
Vexillum (Pusia) exquisitum (Garrett, 1873). A delicate pink shell with two black lines outlining a distinctive white central band. Extremely rare, usually found only as a crabbed shell. These tiny 6mm costellarids live deep within rock and coral rubble at depths of approximately 55 feet. Photo by Sid Sneider. (More about this species in the Identification Section)
Lienardia rubida Hinds, 1844. The ruby turrid. A half inch or smaller. Found in rubble in shallow water down to 90 feet. Uncommon on Guam.
Jul-Sep 1979
Left: Eucyclotoma hindsii (Reeve, 1843). Right: Favartia guamensis Emerson & D'Attilio, 1979.
Eucyclotoma hindsii (Reeve, 1843). This small 11mm turrid is one of a number of rare shells found beneath rubble in Apra Harbor. It prefers the underside of large coral heads. It is characterized by the latticed sculpture of elevated spiral cords, forming window like spaces with the elevated ribs. A shell previously reported from Japan and the Philippines, Guam is a new range extension. This turrid remained unfigured in modern manuscripts until 1975 when this very shell was pictured and described by Walter Cernohorsky in the "Rec Auckland Inst. Mus." 12:213-234.
Favartia crouchi Sowerby, 1894. This tiny 8mm Murex is one of only four shells named after the island of Guam (previously called Favartia guamensis, now a synonym of F. crouchi.). This species is variable in color being yellow, brown, red, and red with white blotches. It is found in silt on and under coral rubble in fairly deep water (60'). This species is not limited strictly to Guam. It has been found on both Kwajelein and possibly Tahiti. ((More about this species in the Identification Section)
Apr-Jun 1979
by Richard Salisbury
Left: Vexillum (Costellaria) radius Reeve, 1845 & Vexillum (Costellaria) obeliscus Reeve, 1844. Center & Right: Distortomina pusilla (Pease, 1861).
Vexillum (Costellaria) radius Reeve, 1845. A small 10mm Costellarid. These shells are white with varying shades of brown banding. They usually have a white central band. Some specimens are white from the suture down to the center of the body whorl. Occasionally these shells are found in Apra Harbor in fine silty sand. A second species, Vexillum (Costellaria) obeliscus Reeve, 1844, is often found with this shell. C. obeliscus is identicle in sculpture and banding. It is, however, broader and a light yellow-green color, C. radius should be considered uncommon.
Distortomina pusilla (Pease, 1861). This tiny 10mm Distortio is the smallest living member of the family. For many years this species was believed to be extinct. It was described from fossils found in Hawaii and Japan. Discovered here in Guam in 1973 beneath piles of boulders near North Tipalao in 30 fett of water. It remains one of Guam's unique rare shells. Safron in color, with spots and streaks of brown, usually hidden beneath a rather dull brownish periostracum. (More about this species in the Identification Section)
Oops!
You've probably noticed a few errors in the first issue of the "Guam Shell News." One of the more obvious mistakes was recently pointed out to me by a longtime member, Sid Sneidar. The turrid pictured under the ID Column identified as Turris spectabilis Reeve, 1843 is misidentified. The correct identification is Turris garnonsii, Reeve, 1843. A species previously found from the western Indian Ocean to the Philippines. This new westward range extension, to Guam, has been verified by Dr. R. Tucker Abbott.
Please note this ID is shown correctly below.
Jan-Feb 1979
by Richard Salisbury
Left: Mitra (Nebularia) rubiginea A. Adams, 1855 & Mitra fraga Gaimard, 1833. Right: Turris garnonsii Reeve, 1843
Mitra (Nebularia) rubiginea A. Adams, 1855. A large red-orange Miter found in Apra Harbor under coral heads. Uncommon on Guam.
Mitra (Nebularia) fraga Quoy & Gaimard, 1833. A large to medium size Miter. Red in color with yellow pustules evenly spaced around the raised spiral ribs. Found beneath coral and rubble around most of Guam. fairly common.
Turris garnonsii Reeve, 1843. A large turrid from Guam. Rarely found. It is a sand dweller. One of the largest turrids found here on Guam it is not too likely you will miss the colorful brown and white pattern of this shell.