CANADIAN PLAICE; LONG ROUGH DAB
[Jordan and Evermann, 1896-1900, p. 2614.]
The most obvious distinctive characters of the American dab are that it is right-handed and large-mouthed like the halibut, but with a rounded tail instead of concave, and with the lateral line nearly straight instead of arched; it is the only Gulf of Maine flounder in which these characters are combined. Our only other large-mouthed flat-fishes with rounded tails (the [page 260] sand-, summer- and four-spotted flounders, pp. 290, 267, and 270) are left-handed, and the wide-gaping jaws readily distinguish the American dab from the various small-mouthed flounders.
It is a comparatively broad (really deep) flounder (about two and one-half times as long to base of caudal fin as it is broad), more rounded in outline than the halibut, with pointed nose, mouth gaping back to abreast of the middle of the eyes, and with one irregular row of sharp conical teeth in each jaw. The free edges of the scales on the entire eyed (upper) side of its body and of its head are serrated with sharp teeth, which give the fish a characteristic rough feeling when handled, but the scales of the blind (lower) side are smooth-edged except on the rear part of the body and along the bases of the fins. The dorsal fin (76 to 96 rays) originates in front of the middle of the left eye and the anal fin (64 to 77 rays) arises slightly in advance of the base of the pectorals. Both of these long fins taper toward the head and toward the tail, and there is a short, sharp, spine (the prolongation of the post abdominal bone) pointing forward close in front of the anal fin. The pectoral fin on the eyed side usually (not always) has one or two more rays than its fellow fin on the blind side, and is longer and more rounded, but the two ventral fins, which are close in front of the anal fin though entirely distinct from it, are alike in size, shape, and location. The margin of the caudal fin is always convex, either rounded or with its middle rays so much the longest as to form a blunt angle. The lateral line on the eyed side is more clearly evident on the dab than on most of our flatfishes, and it is straight from end to end, except for a slight arch over the pectoral fin.
Dabs run more uniform in color than most of our smaller flatfish, ranging from reddish to greyish brown (darker or paler) above and pure or bluish white below. The tips of the rays of the two long (dorsal and anal) fins are white. On one specimen we saw the right edge of the eyed side was white (like the blind side) from the gill opening to the rearmost ray of the ventral fin but this is unusual. Small fish are usually marked with three to five dark spots along each edge of the body; large ones are occasionally, though they are plain colored as a rule.
Adults measured by Welsh off Cape Ann ran from about 12 inches to 24 inches, and few of those that are caught in our Gulf are longer than 2 feet. Nova Scotian fish measured by Huntsman ran from 12 to 24 inches in length, while fish caught in the colder waters off Newfoundland averaged 18 inches. The largest dab recorded from American waters, taken near Sable Island, May 1939, was 32½ inches long and weighed 14 pounds. The next largest, taken in 90 fathoms on the northern edge of Georges Bank, November 1951, was 29 inches long.
According to Huntsman, Nova Scotian fish average about half a pound at 12 inches, 1¼ pounds at 16 inches, 1¾ pounds at 18 inches, 2¾ pounds at 20 inches, 4 pounds at 22 inches, and 6 pounds at 24 inches. Massachusetts Bay fish are about equally heavy at corresponding lengths. And a 16-inch fish from Georges Bank that we measured weighed 1 pound 5 ounces; two fish of 18¼ inches weighed 1 pound 13 ounces, and 2 pounds, respectively; one of 19½ inches weighed 2 pounds 8 ounces, and one of 29 inches weighed 9 pounds 6 ounces.
This flatfish tends to differentiate into local races in different seas. Thus the fin rays are more numerous on the average in fish from high latitudes than in those from low latitudes, while the body is relatively wider in fish caught off Greenland and off America than in those from Scandinavia and from the North Sea. But these characters vary so widely even in limited areas that the Arctic-American and European species (platessoides and limandoides) have been united by common consent long since, and we doubt whether the corresponding "varieties" still recognized by several recent authors will stand the test of time. Huntsman's statement that the dorsal rays average more numerous in dabs from Bay of Islands, Newfoundland, than in those caught on the New Brunswick shore of the Gulf of St. Lawrence, with Welsh's note of a variation of 7 in the number of dorsal rays and of 6 in the anal rays in one lot of fish caught off Gloucester, illustrates this variability. Notwithstanding the low latitude of the locality of capture (about 42° 30' N.), this same lot contained a specimen with the largest number of fin rays yet reported (96 dorsal and 77 anal).
All we dare say until many more specimens are examined is that hereditary local races may perhaps exist off different parts of the American [page 261] shore line, and that the growth marks on the scales, in relation to the length of the fish, may give a clue to the local origin of a given specimen, for it seems that the rate of growth is governed by the temperature of the water (p. 263).
Dabs are bottom fish like other flatfishes. But they must rise some distance from the ground on occasion, and move about to a considerable extent to account for the capture of so many in gill nets (p. 264). We once caught one a foot long in a tow net at least 5 to 10 fathoms above the bottom off Ipswich Bay, where the water was about 50 fathoms deep.
Like some other flatfishes, they avoid rocky or hard bottom, preferring a fine, sticky but gritty mixture of sand and mud, such as floors much of the Gulf between the hard patches, from the 20 fathom contour out to the 100 fathom contour. And they are also to be caught in numbers on the soft oozy mud of the deeper basins in the western side of the Gulf, as pointed out below (p. 264).
In one part of their range or another, they are found from tide line down to as deep as about 390 fathoms (700 meters).
This is an arctic-boreal species in its temperature relations, reaching its highest development in water of 35° to 45° F.; able to live, however, in the lowest polar temperatures (29° to 30°); and finding the upper temperature limit to its regular occurrence at about 50° to 55° F.
In different seas it lives through a wide range of salinity, from 30 per mille or lower in the Baltic to upwards of 34 per mille in the open Atlantic. So far as we are aware, it is never found in water which could be described as brackish along the coasts of New England or of the Maritime Provinces. But R. H. Backus informs us that the Blue Dolphin found it in brackish water (salinity 23 per mille) at the west end of Lake Melville, Labrador.
Huntsman's statement that it feeds on minute planktonic plants (diatoms) at first, but on copepods as it grows larger and more active is our only information as to the diet of the young fry in American waters, while they are drifting near the surface. When they first take to the bottom they eat small shrimps and other Crustacea of various sorts. But they turn (as they grow) to a diet consisting chiefly of sea urchins, sand dollars, and brittle stars, as proved by the contents of their stomachs, though they also take various shrimps, hermit and spider crabs and other crustaceans, mollusks, worms and ascidians (sea squirts), in fact, practically any bottom living animals that are small enough for them to devour. Occasionally they catch small fish.
They do not bite a baited hook as readily as various other ground fishes, partly, no doubt, because they are sluggish fish, but partly, we believe, because the clams, cockles, and herring that are usually used for bait are not their favorite food. Still, considerable numbers are caught on hand and long lines.
All the large predaceous fish that feed near bottom probably prey more or less upon them, and halibut no doubt destroyed great numbers of them in the Gulf of Maine formerly. But the adults can have no serious enemy in our Gulf today except large cod and perhaps the spiny dogfish. In more northern seas Greenland sharks prey regularly on them. Smitt and Huntsman both speak of the numbers of round worms to be found in the intestines and body cavity of the dab, and its gills are sometimes attacked by parasitic copepods.
While the young are drifting near the surface (p. 262), they share in the same involuntary journeyings; as other fish fry do, that are spawned at the same place and time. But it is one of the more stationary fishes from the time it seeks bottom. It has been said to work inshore more or less in winter, though not on very definite evidence, and it may congregate on definite grounds for spawning, though this is yet to be proved. But it is certain that they are to be caught at any season of the year wherever they are plentiful. And Huntsman who has paid special attention to this fish, believes that it "remains pretty much in the same place from season to season and year to year. Perhaps in the course of years it may shift a few miles."
Individual females produce 30,000 to 60,000 eggs, according to size. The eggs are buoyant and have no oil globule, but they have a transparent (perivitelline) space around the yolk so broad that they are not likely to be confused with those of any other Gulf of Maine fish. [page 262] This space is formed by the entrance of water between the egg proper and its covering membrane, after the eggs are shed, and it about doubles the total diameter of the egg. The eggs we have taken in the Gulf of Maine have averaged about 2.5 mm. in diameter, but they have been reported as small as 1.38 and as large as 3.2 mm. in other seas, depending on the breadth of the perivitelline space.
Incubation occupies 11 to 14 days at a temperature of 39° F., and it seems that the eggs gain weight as development proceeds, for Huntsman found, in the Gulf of St. Lawrence, that the newly spawned eggs floated at the surface, but that eggs nearly ready to hatch drifted suspended at a depth of some 10 fathoms. We have no first-hand information to offer on this point.
During the development of the egg, minute black and yellow pigment cells are scattered over the embryo, not aggregated into any diagnostic clusters. But the pigment gathers in five definite groups very soon after hatching (which takes place when the larvae are 4 to 6 mm. long); one on the gastric region, one about the vent, and three behind the vent; a pattern similar to that of the larval witch flounder (p. 287).
The yolk is absorbed about 5 days after hatching, when the larva has grown to 6.2 to 7.5 mm. in length. The caudal rays appear shortly after this, the dorsal and anal rays at about 11 to 12 mm., and the three vertical fins are differentiated at about 15 to 18 mm. By this stage the body has begun to assume the deep but very thin form characteristic of all young flounders, while the jaws have developed sufficiently to show that the little fish belongs to one of the large-mouthed species. The left eye may commence its migration when the larva is about 20 mm. long, while Welsh found it visible above the outline of the snout in Gulf of Maine specimens of 24 mm., and almost at the dorsal edge at 34 mm. But larvae as long as 35 mm. may still be symmetrical in other seas.
The only other Gulf of Maine species for which the larval dab might be mistaken (except in its very earliest stages) are the witch flounder and the halibut; but the witch is longer at corresponding stages of development, but with the distance from snout to vent proportionately much shorter, and the outlines of throat and abdomen are sufficiently different to distinguish the dab from the halibut (p. 253).
The young dab drifts freely up to the time of its metamorphosis, as the young of most sea fishes do; close to the surface at first but sinking deeper as it grows, until it seeks the bottom finally. [page 263] Welsh's observations suggest that this takes place, in our Gulf, when the little fish are about 1½ to 1¾ inches long, with their metamorphosis already complete, their body scaly, and their eyed side densely pigmented. But there is wide variation in this respect. And European authors report that the fry may take to the bottom even before the left eye has completed its migration around the head.
The period occupied in larval growth and in metamorphosis varies with temperature. Probably it covers three to four months in the Gulf of Maine, where we have taken the pelagic larvae as early in the season as May 26 and as late as August 2.
The little fish grow to a length of 2 to 3 inches by their first winter, with their exact size then depending upon how early in the season they are hatched, and probably on the temperature in which they live. And they average about 3 inches long when they are one year old. Thus it may be assumed that bottom stages 2¾ to 31/8 inches (69-80 mm.) long that we have trawled off Cape Cod, on May 1, were about one year old, others of 33/8 to 45/8 inches (85-118 mm.) that we have trawled in July and August off Mount Desert, in the deep gully to the westward of Jeffreys Ledge, on Cashes Ledge, and on the edge of Stellwagen Bank were between 1¼ and 1½ years old; and that those of 8 to 10 inches were 2¼ to 2½ years old. Subsequent growth is more rapid in higher temperatures than in lower, throughout the temperature range favorable to this particular flatfish. Huntsman, for example, has found that it takes only 3 to 5 years for dabs to grow to a length of 12 inches in Passamaquoddy Bay, where the bottom water at 15 to 18 fathoms warms to about 49° to 51° F. in August, but that it requires 4 to 6 years in the open Bay of Fundy, where the bottom temperature in summer is somewhat lower (45°-48°); 6 to 9 years in the cooler water (about 38°) of Chedabucto Bay, eastern Nova Scotia; and upwards of 8 years in the still lower temperatures (colder than 35°) of the Gulf of St. Lawrence.
On this basis, dabs living on the shoaler parts of Georges Bank, and as shoal as 15 fathoms or so in coastwise waters from Cape Cod to Cape Elizabeth, probably grow about as fast as the Passamaquoddy Bay fish, i. e., they may reach a length of 15 inches in 5 years or even sooner, gaining something like 4 ounces in weight yearly. Those in the eastern side of the open Gulf of Maine may be expected to grow about as fast as those in the Bay of Fundy, but somewhat more slowly there if they are living as deep as 50 fathoms, though not so slowly as in the Gulf of St. Lawrence. Some individuals may become sexually mature when only 6 inches long, probably all of them do so by their third year; and they are known to live to an age of 24-30 years, perhaps longer, at least in the Gulf of St. Lawrence.
In general, females grow faster than males.
Huntsman has also found, in the Gulf of St. Lawrence, that a majority of the fish of 3 years and younger were males, but that females outnumbered the males among the older fish, while all of those 14 years old and older that he saw were females. We have no explanation to offer for this (apparently) higher mortality rate for the males than for the females among the older fish.
This is a very common fish on both sides of the North Atlantic, where its range parallels that of the cod, except that it does not extend as far south and west along the American seaboard. It is found in abundance along the outer coast of Labrador, southward from Hamilton Inlet, where (Frost writes) they are so abundant locally that a 5-minute haul with a torn trawl yielded 50 (at lat. about 54°) in Newfoundland waters in general; on the Grand Banks, including the eastern edge; in the Gulf of St. Lawrence as a whole, and thence westward and southward to Cape Cod, from close inshore out to the 100 fathom contour. Westward from Cape Cod, a few are caught in the Woods Hole region; off Marthas Vineyard; and off Narragansett Bay which marks their western limit in general. The most southerly and westerly record with which we are acquainted is of one 15½ inches long that was caught off Montauk Point, N. Y., in 112 fathoms, February 6, 1930.[page 264]
It is common in west Greenland waters, as far north as Upernavik near the Arctic Circle, in latitude about 72° N. And it ranges in European waters from Iceland and Spitzbergen southward to the North Sea, where it is an important commercial fish, and to the west Baltic; the English Channel is the southern boundary to its regular occurrence.
This is not as familiar a fish as are the winter and smooth flounders (pp. 276 and 283), for it is not common in water shallower than 15 to 20 fathoms. But it is probably the most abundant of all Gulf of Maine flatfishes at depths greater than 30 to 50 fathoms, except, perhaps, the witch (p. 285). Thus they are recorded from Provincetown; from Massachusetts Bay; off Cape Ann; on Stellwagen Bank, where we have hand-lined a number of them in 25 fathoms; in Ipswich Bay; near Boon Island; off Cape Porpoise; off Casco Bay; on Cashes Ledge, where we have trawled both young and adults; off Seguin; south of Monhegan (we trawled them at the last four localities on the Grampus); close in to Little Duck Island, off Mount Desert; in Passamaquoddy Bay; in St. Mary Bay; and right up to the head of the Bay of Fundy. In fact, they are to be caught all around the inner parts of the Gulf wherever the water is more than 15 fathoms deep or so, and where the bottom is smooth. Trawlings, too, by the Albatross II and by the Atlantis have shown that they are generally distributed throughout the basin of the Gulf down to 120 fathoms. This, indeed, was the only flatfish, other than the witch (p. 288), that was taken by the Atlantis on the soft mud bottoms off Cape Cod, west of Jeffreys Ledge, or off Mount Desert, at 66 to 105 fathoms during her experimental trawlings for the edible shrimp (Pandalus) in August 1936.
Dabs are widespread on Georges Bank also, for they were reported at many localities there by representatives of the Bureau of Fisheries in 1913, while we have seen catches of up to 100 per trawl haul on the northern edge of Georges, in 60 to 100 fathoms of water. They are so plentiful along the 50-100 fathom zone on the northern edge of Georges Bank that draggers fishing there during 1951-1952 were making catches averaging about 5,000 pounds per day. A good example of their numbers there is furnished by the dragger Eugene H of Woods Hole which brought in catches of 10,000 to 25,000 pounds of dabs, fishing in 75 to 95 fathoms, throughout the period August 1951 to January 1952. Many of these fish were large, ranging from 4 to about 9 pounds in weight. And in this same region, in the spring, they appear to be plentiful in water much shoaler, for Capt. Arthur Nelson of Woods Hole reports a catch of 18,000 pounds taken in 25-30 fathoms in four days' fishing early in May 1952. Also, we have the definite evidence of commercial catches, as well as of newly spawned eggs taken in our tow net, that dabs are plentiful on Browns Bank also.
Huntsman has calculated from fishing experiments that they are about one-tenth as numerous as cod in the Gulf of St. Lawrence. No general estimate of this sort is yet possible for the Gulf of Maine. But catches in gill nets (gear not very well adapted for flounder fishing) of 76 dabs to 1,055 haddock, 51 cod, 20 pollock, and 39 rosefish near Boon Island on March 30; of 125 dabs to 40 other flounders, 89 cod, and 113 haddock in part of the net at the same locality on April 20; and of many dabs, but more cod and haddock, on May 3, 1913, are pertinent here.
This flatfish is often found in very shoal water in colder seas. They are often seen under wharves around Newfoundland, for example, according to Frost. And some are seined right on the beach on the West Greenland coast. But we have never seen or heard of an adult specimen caught in less than 10 fathoms of water in the Gulf of Maine, probably because of the high summer temperatures of the shoaler waters, and they are the most plentiful in 15 to 60 fathoms there (in our experience). At the other extreme, 120 fathoms is the deepest definite record for the Gulf of Maine with which we are acquainted; hence this may be set as the lower limit to their occurrence there in any numbers, which, by report, applies to the whole American coastline, including the Scotian banks and the Grand Banks region.
This preference of the dab for moderately deep water in the southern part of its range bars it from most of the Gulf of Maine harbors and river [page 265] mouths, which are such favored haunts for the winter flounder. But it enters the deeper estuaries and passages between the islands in the northeastern part of the Gulf, those near Mount Desert, for example, Passamaquoddy Bay, and St. Mary Bay.
We hesitate to draw any definite conclusions from published statistics of the landings of "dab" as to the regional abundance of this particular flatfish in our Gulf, partly because of the likelihood that other flatfish may appear under this name, or dabs under some other name, and partly because only a few of the otter trawlers fish in the deeper basins of the Gulf where dabs are known to be plentiful.
The returns for 1945, if taken at face value, show about 48,000 pounds landed from off eastern Maine; about 586,000 pounds from off central Maine; about 311,000 pounds from off western Maine; about 43,000 pounds from small grounds in the west central part of the Gulf; about 897,000 pounds from off eastern Massachusetts; about 8,000 pounds from Nantucket Shoals; about 910,000 pounds from the South Channel and Georges Bank combined; about 48,000 pounds from Browns Bank; and about 40,000 pounds from off western Nova Scotia (by United States fishermen); or a total of some 2,890,000 pounds. It was not until 1946 that the dab was listed (as "Canadian plaice") in the Canadian fisheries statistics for Nova Scotia; in that year landings for western Nova Scotia (Yarmouth County) were about 140,000 pounds, and about 41,000 pounds for the Nova Scotian side of the Bay of Fundy (Digby County).
The presence of dabs or Canadian plaice of catchable sizes in the Bay of Fundy in general, and in Passamaquoddy Bay in particular, is interesting as evidence that this is not so stationary a fish there as it seems to be elsewhere, for none are reared there so far as is known (p. 266), so that the maintenance of the local stock appears to depend on immigration from outside. Huntsman's observation is interesting, too, that large ones form a much smaller proportion of the population in Passamaquoddy Bay and in the Bay of Fundy than they do in the Gulf of St. Lawrence. And it seems, similarly, that large ones are less plentiful relatively in Passamaquoddy Bay than they are in the western side of the open Gulf of Maine. The death rate may be higher in Passamaquoddy waters, as Huntsman has suggested, or it may prove that the fish tend to work out from there into the open Gulf as they advance in age.
The dab is a spring spawner on both sides of the Atlantic, as is well known. The earliest date at which we have taken its eggs in our tow net in the Gulf of Maine has been March 4 (in 1920), off Casco Bay. We have also found the eggs on Browns Bank on the 13th, while Welsh records large female fish, half spent and with eggs exuding, as well as males with running milt, on the 14th of March, near Cape Ann, in 1913. But other fish of both sexes taken with them were unripe still, evidence that spawning is not general until the last of March or first part of April. Dab eggs have appeared regularly in our towings in April (twice in great numbers, namely off Seguin Island on the 10th and off Mount Desert Island on the 12th in 1920). Spawning continues unabated throughout May, when eggs were taken at nearly all our towing stations in 1915. And April and May similarly cover the height of the spawning season in the Bay of Fundy, according to Huntsman. Our latest seasonal record has been for a single egg, on the 14th of June in 1915.
The dab spawns chiefly during May and June on the banks off Cape Breton and in the southern part of the Gulf of St. Lawrence: until the end of July on the southern part of the Newfoundland Banks (a few eggs were found by the Canadian Fisheries Expedition); until fall around the southeastern and eastern coasts of Newfoundland, and along the outer coast of Labrador, according to Frost. And the eggs are reported from May into July off West Greenland, by Jensen.
It spawns somewhat earlier in the North Sea than in American waters; i. e., from mid-January till May with the climax in March and April. Huntsman also remarks that there is a difference in the breeding season according to the depth of water, those living shoalest commencing to spawn the earliest, as the vernal warming of the water makes itself felt from above. But we have no clear evidence on this point to offer for the Gulf of Maine.[page 266]
Our egg records, added to Huntsman's observations, show that the dab spawns all around the Gulf of Maine, from Cape Cod on the west to Cape Sable on the east, including the Bay of Fundy, and from close inshore out to the 50-fathom contour. It also spawns on Browns Bank (p. 265), and, while we found no eggs on Georges Bank either in February, March, April, or May, of 1920, the fish is so common there and so stationary in general that it is likely that we simply missed its eggs, either by a failure to tow over the precise spawning localities or by timing our visits between the waves of production. Dabs also spawn abundantly on Sable Island Bank (no doubt on all the other Nova Scotian Banks); off Cape Breton; in the shoaler parts of the Gulf of St. Lawrence; throughout the general region of the Grand Banks; off the east coast of Newfoundland; along the outer coast of Labrador to Hamilton Inlet at least; and as far north along the west coast of Greenland as the species is known to exist, as is proven by the presence of its eggs in the water there in quantities.
Although the dab is rather a deep-water fish compared to most of the other flatfishes that are common in the Gulf of Maine, it is doubtful whether it ever spawns at depths much greater than 50 fathoms in the Gulf, for we have few egg records from more than a mile or two outside the 50-fathom curve, while these few have been based on only one or two eggs each. And we have trawled spawning females off Mount Desert, in 20 fathoms. This concentration of our egg catches inside the 50-fathom contour implies that the dabs that live deeper in our Gulf tend to work up into shoaler grounds to spawn. Beyond this, there is no reason to suppose that they gather in any definite localities for the purpose.
The temperatures and salinities in which the eggs are produced can be stated rather definitely for the Gulf of Maine because the dab lies close to the bottom, if not actually on it. The earliest spawning takes place at nearly the minimum temperature for the year, averaging about 37° for all the March and April stations where eggs were taken. And while the water warms to 41°-43° F. by late May and early June at the depths known to be inhabited by the ripe fish, we have not found its eggs where the bottom temperature was higher than about 40°. Thus the optimum for breeding may be set at 37°-40° for the Gulf of Maine as a whole. Dabs spawn freely in 31°-32° off Cape Breton, and even in water as cold as 29.3°-32° in the Gulf of St. Lawrence, in Newfoundland waters and northward, as well as along the West Greenland coast, proving that the lowest polar temperatures are no bar to the ripening of its sexual products. Neither does the distribution of the bottom stages suggest that warmer water is needed for the survival of the resultant larvae.
In the Gulf of Maine the dab spawns in relatively low salinities, the range there being only from about 31.8 per mille to about 32.8 per mille at the bottom at the stations where eggs were taken in any number. But it does so in considerably more saline waters in the other side of the Atlantic, generally speaking.
Although this flatfish spawns so generally throughout the whole area that it inhabits, there is evidence that different regions differ in their suitability as nurseries, either for its eggs or for the larvae. The southwestern part of the Gulf of Maine must be favorable in this respect, for we have taken larval dabs at 14 stations there, most of these off the Massachusetts Bay region. And they have also been taken at various localities off the southeast coast of Nova Scotia; on the Newfoundland Banks; in the Gulf of St. Lawrence; along the east coast of Newfoundland; in the Strait of Belle Isle; and northward for some distance along the outer coast of Labrador. But it seems that reproduction does not succeed in the Bay of Fundy, for neither the larvae nor the young fry have ever been found there, although dabs spawn there and the eggs develop, at least partially. Failure to find any dab larvae off the coast of Maine east of Penobscot Bay, though eggs are produced there in abundance may be due to the prevailing drift from northeast to southwest along this part of the coast, because of which buoyant eggs produced there are likely to hatch a considerable distance to the west of where they were spawned. The influence that this drift may have on the distribution of larval fish in the Gulf of Maine offers a fertile field for future study.[page 267]
This is an excellent pan fish, but there is no special demand for it in New England markets, as distinguished from other flat fishes of about the same size. If the landings reported as "dab" do not include any significant proportion of other flounders, and if most of the dabs that are taken are reported under that name, the yearly catch in the Gulf by United States fishermen ranged between about 2,700,000 pounds and about 4,400,000 pounds for the period 1942 to 1947, averaging about 3,600,000 pounds. In 1946 Canadian fishermen brought in an additional 181,200 pounds from the eastern side of the Gulf and from the Bay of Fundy, plus an indeterminate amount landed in Shelburne County from Cape Sable to the Yarmouth County line. We have no doubt that the catch could be increased greatly in our Gulf if any special demand were to develop for dabs.
The dab lives too far out from the land, on the whole, and too deep, and it does not bite eagerly enough for it to be of any interest to anglers along our shores.
 Various other common names are applied to this fish in different seas. It is usually termed "Long rough dab" in England and is so listed in British fishery statistics. It is not the "plaice," or the "dab" of Europe.
 Bull. No. 1, Biol. Board Canada, 1918, p. 10.
 Frost, Res. Bull. 4, Newfoundland Dept. Nat. Resources, 1938, p. 8.
 McKenzie, Proc. Nova Scotian Inst. Sci., vol. 20, 1940, pp. 43-44.
 We measured this dab, taken by Capt. Arthur Nelson of the Eugene H. who also caught several others, 27 to 28 inches long on this same trip.
 Bull. Biol. Board Canada, No. 1, 1918, p. 15.
 Bull. Biol. Board Canada, No. 1, 1918, p. 18.
 Huntsman, Bull. Biol. Board Canad, No. 1, 1918.
 Bull. Biol. Board Canada, No. 1, 1918, p. 23.
 Res. Bull. 4, Newfoundland Dept. Nat. Resources, 1938, p. 8. R. H. Backus informs us also that the Blue Dolphin collected them at various localities as far north as the northern shore of Hamilton Inlet (lat. 54° 30' N.), but did not take any farther north, in spite of extensive collecting.
 Reported in abundance down the eastern edge of the Grand Banks, in the 20th Rept. Dept. Fish. Canada (1949-1950) 1951, p. 36.
 We find no other credible records from New York or from New Jersey, those mentioned by DeKay being market fish which might have come from anywhere to the eastward.
 For an account of it in west Greenland waters, see Jensen (Meddel. Dansk Komm. Havundersøgelser, vol. 7, No. 7, 1925, p. 24).
 Huntsman (Bull. 1, Biol. Board Canada, 1918) gives an interesting account of this fish in Canadian waters.
 Bigelow and Schroeder, Biol. Bull., vol. 76, 1939, p. 308.
 Recorded by Welsh.
 Research Bull. 4, Newfoundland Dept. Nat. Resources, 1939, p. 8.
 Jensen, Meddel. Dansk. Komm. Havundersøgelser, Ser. Fiskeri, vol. 7, No. 7, 1925, p. 24.
 It is only during the past few years that the landings of this particular flatfish have been reported separately, as "dab."
 Bull. 1, Biol. Board Canada, 1918, p. 14.
 Dannevig, Canadian Fisheries Expedition (1914-15) 1919, p. 18, figs. 11, 12, and 13.
 See Frost, Res. Bull. No. 4, Newfoundland Dept. Nat. Resources, 1938, chart 2, for the regional and seasonal distribution of dab eggs in Newfoundland and Labrador waters.
 Jensen, Meddel. Dansk. Komm. Havundersøgelser, Ser. Fiskeri, vol. 7, no. 7, 1925, p. 24.
 The landings for that year were 60,100 pounds for Shelburne County as a whole.