Common grenadier Macrourus bairdii Goode and Bean 1877 ^[1]

RAT-TAIL; MARLIN-SPIKE

Description—

This grenadier could hardly be mistaken for any other fish except for one of its own tribe, so characteristic is its slender body (flattened sidewise behind the vent and tapering to a whiplike tail with no definite caudal fin), in combination with a pointed snout that overhangs the mouth; very large eyes; and high first dorsal fin with one large spine; but very low second dorsal fin. And it has a chin barbel like a cod (not shown in the illustration). As noted above, the second ray of the first dorsal fin is a true spine, serrated along its front edge with about 15 sharp and very noticeable teeth pointing upwards.

The first dorsal fin (2 stiff rays, the first very short, and 11 softer rays) is triangular, about twice as high as it is long; and it originates over the pectorals, close behind the gill openings. The space between the two dorsal fins is about as long [page 244] as the height of the first dorsal fin. The second dorsal fin (about 137 rays) extends back to the tip of the tail, is so low that its membrane is hardly visible, and tapers to practically nothing at the rear end. The anal fin is considerably longer than the second dorsal (only about 120 rays, however) and more than twice as high as the second dorsal. The pectoral fins are rounded at the tip, The ventral fins, which stand under the pectorals or a little behind the latter, are triangular, with the first ray prolonged as a threadlike filament.

The exposed parts of the scales on the body, including the head and shoulders, are rough with minute sharp spines closely crowded together. The jaws are armed with several bands of small recurved teeth. The vent is situated a considerable distance in front of the point of origin of the anal fin, and the skin immediately surrounding it is scaleless and black.

Color—

The many we have seen have been uniform gray above and below. Also described as light brownish gray above, silvery below, with dark bluish or blackish belly. The lower surface of the snout is pink, the throat is deep violet, the first dorsal is pink with blackish spines, and the eyes are dark blue.

Size—

Usually about 1 foot long. The largest we have seen was 16 inches long.

Habits—

Grenadiers are bottom fish, usually found on soft mud, and they are very feeble swimmers. They usually live in at least 80 to 90 fathoms of water, and down to 1,000 to 1,200 fathoms (deepest record 1,255 fathoms). But one was trawled in 9 fathoms in Vineyard Sound by the Fish Hawk many years ago; a second was found floating near the surface at Eastport, Maine, by Dr. W. C. Kendall; and a third was taken in a weir at Lubec, Maine, as reported by Huntsman.

Hansen^[2]reports pelagic euphausiid shrimps (Thysanoessa longicaudata) in a grenadier stomach, while several examined by us from 100 fathoms on the edge of Georges Bank contained amphipods chiefly, together with an occasional worm and euphausiid shrimp.

It is probable that grenadiers spawn in summer and autumn, for the spermaries of a specimen taken in the western basin of the Gulf on August 19 were nearly ripe, while a fully ripe male has been reported from South Channel in the last week of September. The eggs of this fish have not been seen, but it is probable that they resemble other macrourid eggs described by European authors^[3] in being buoyant at least for the first part of the period of incubation, with a large oil globule, wide perivitelline space, and with the surface sculptured into concave hexagonal facets. The larvae have not been seen yet. Those of other species of grenadiers have the rays of the first dorsal and ventral fins greatly prolonged.

General range—

This (normally) deep-water fish has been found at many localities along the continental slope from the West Indies northward and eastward to the Grand Banks of Newfoundland,^[4] and rarely in the Gulf of St. Lawrence. It is also known from the mouth of the Laurentian Channel, on the Scotian Banks, in the Gulf of Maine, and even in Vineyard Sound. It has also been reported from the Azores.

Occurrence in the Gulf of Maine—

The common grenadier was formerly regarded as a rare stray in the inner parts of the Gulf of Maine for only two had been recorded there aside from the Eastport and Lubec specimens mentioned above, the [page 245] one from the western basin in 160 fathoms, the other from off Gloucester, both of them taken many years ago. But they must be rather common on the muddy bottoms of the deeper parts of the Gulf in 85 to 125 fathoms, for we have caught more than 100 of them at various localities on recent trawling trips. No doubt it is because few vessels ever fish on these grounds, which are not productive either of cod or of haddock, that the presence of grenadiers there has been overlooked. A grenadier, too, was reported from the slope of Jeffreys Ledge, in about 50 fathoms, during March 1934.

Grenadiers, together with the long-finned hake (p. 232), are the most abundant fish on the continental slope abreast of the Gulf below 100 fathoms.^[5]