Studies of Haddock in the Passamaquoddy Bay Region

1960 ◽  
Vol 17 (2) ◽  
pp. 175-180 ◽  
Author(s):  
F. D. McCracken
Keyword(s):  
New England ◽  
Early Summer ◽  
Small Fish ◽  
Large Fish ◽  
Power Structures ◽  
Passamaquoddy Bay

From 1954 to 1957 haddock within Passamaquoddy Bay have been of intermediate sizes. Few small fish or large fish have been captured either by commercial fishermen or in small-mesh research nets. Tagged fish of the Passamaquoddy Bay region moved out of the Bay during winter and mingled mainly with haddock stocks off the New England States. In the following summer recaptures of tagged fish were again most numerous within Passamaquoddy Bay. Stocks of haddock within the Bay appear to result from annual migrations into the Bay in early summer. It is predicted that the proposed power structures would have no effect on haddock stocks outside the high and low pools but that they would probably seriously reduce the haddock population within the high pool.

Size Changes, Mortality, and Equilibrium Yields in an Exploited Stock of American Plaice (Hippoglossoides platessoides)

1969 ◽  
Vol 26 (5) ◽  
pp. 1205-1235 ◽  
Author(s):  
P. M. Powles
Keyword(s):  
Mesh Size ◽  
Food Competition ◽  
Mortality Factor ◽  
Otter Trawl ◽  
Small Fish ◽  
Large Fish ◽  
Age Composition ◽  
Instantaneous Rate ◽  
Factors Affecting ◽  
Ecological Dominance

Records from research surveys and commercial landings for American plaice from the Magdalen Shallows, or the southwestern Gulf of St. Lawrence, showed decreases in percentage of old, large fish and in catch per unit of effort from 1955 to 1962. The changes in age composition were clearly relatable to the fishery, which was mainly by otter trawl. Ricker models indicated that wastage of deck-exposed subcommercial plaice is currently a greater mortality factor than predation by cod. Increased landings in particular years were associated with successful year-classes. Other factors affecting landings were annual differences in fleet dispersal, which were related to movements of cod, a cohabiting species. No clear decrease or increase in absolute recruitment of plaice was demonstratable because quantitative comparisons of research surveys by different vessels using different gears and with different skippers, would be misleading.Mortality estimates of adult plaice by three methods showed agreement, indicating that instantaneous rate of natural mortality was between 0.09 and 0.13. The instantaneous rate of fishing for 1957–62 was 0.46. Increasing mesh-size would reduce cod catches and have little effect in conserving plaice, but marketing small fish would increase plaice landings. Voluntary release of small plaice promptly on capture would help maintain the stock, as would reduction in numbers of large cod, the main predator of small plaice. Increased numbers of small cod since 1959, as reported by other workers, could result in greater food competition with small plaice, effectively reinforcing the ecological dominance of cod over plaice.

Pectoral fin locomotion in the striped surfperch. I. Kinematic effects of swimming speed and body size

1996 ◽  
Vol 199 (10) ◽  
pp. 2235-2242 ◽  
Author(s):  
E Drucker ◽  
J Jensen
Keyword(s):  
Body Size ◽  
Swimming Speed ◽  
Beat Frequency ◽  
Limited Range ◽  
The Body ◽  
Small Fish ◽  
Large Fish ◽  
Pectoral Fin ◽  
Transition Speed ◽  
Speed Up

Swimming trials at increasing velocity were used to determine the effects of steady swimming speed on pectoral fin kinematics for an ontogenetic series of striped surfperch Embiotoca lateralis, ranging from 6 to 23 cm in standard length (SL). The fin stroke cycle consisted of a propulsive period, the duration of fin abduction and adduction, and a 'refractory' period, during which the fin remained adducted against the body. Pectoral fin-beat frequency (fp) measured as the inverse of the entire stride period, as in past studies, increased curvilinearly with speed. Frequency, calculated as the reciprocal of the propulsive period alone, increased linearly with speed, as shown previously for tail-beat frequency of fishes employing axial undulation. Fin-beat amplitude, measured as the vertical excursion of the pectoral fin tip during abduction, increased over a limited range of low speeds before reaching a plateau at 0.35­0.40 SL. Pectoral fin locomotion was supplemented by intermittent caudal fin undulation as swimming speed increased. At the pectoral­caudal gait transition speed (Up-c), frequency and amplitude attained maxima, suggesting that the fin musculature reached a physiological limit. The effects of body size on swimming kinematics differed according to the method used for expressing speed. At a given absolute speed, small fish used higher stride frequencies and increased frequency at a faster rate than large fish. In contrast, the relationship between fp and length-specific speed (SL s-1) had a greater slope for large fish and crossed that for small fish at high speeds. We recommend that comparisons across size be made using speeds expressed as a percentage of Up-c, at which kinematic variables influencing thrust are size-independent.

New Netherland

2019 ◽  
pp. 43-54
Author(s):  
William E. Nelson
Keyword(s):  
New England ◽  
Long Island ◽  
Director General ◽  
Power Structures ◽  
New Netherland ◽  
Delaware River ◽  
Hudson Valley ◽  
Law System ◽  
The Government ◽  
Civil Law System

This chapter examines the Dutch mercantile colony located on Manhattan Island and in the Hudson Valley up to Albany, English settlements on Long Island, and a small initially Swedish colony along the lower Delaware River. Its main focus is on the legal system created by the Dutch. It was a sophisticated, centralized, civil law system that reposed ultimate decisional power in the hands of a director-general directing the government from Manhattan Island and in the hands of his superiors in the Netherlands. The English settlements on Long Island, on the other hand, copied the localized power structures of New England, although the Long Islanders operated more informally and less learnedly. Dispute resolution in the tiny colony along the Delaware was unlearned and totally informal.

Cardiac output determinations by the dye-dilution method in Squalus acanthias

1965 ◽  
Vol 209 (4) ◽  
pp. 723-726 ◽  
Author(s):  
H. Victor Murdaugh ◽  
Eugene D. Robin ◽  
J. Eugene Millen ◽  
William F. Drewry
Keyword(s):  
Cardiac Output ◽  
Cardiac Index ◽  
Squalus Acanthias ◽  
Physiological Status ◽  
Dilution Method ◽  
Small Fish ◽  
Large Fish ◽  
Dilution Technique ◽  
Dye Dilution ◽  
Cardiac Output Measurements

A dye-dilution technique has been adapted for the measurement of cardiac output in the elasmobranch, Squalus acanthias. Cardiac output averaged 1.60 ± 1.00 liter/kg per hr in 26 fish. Small fish showed a relatively high cardiac index (liters/kg per hr) as compared with large fish. The use of this technique permits sequential cardiac output measurements with the maintenance of an intact physiological status. This technique should permit quantitation of exchange of a variety of substances across the gill membranes.

scholarly journals The relation between concentrations of ovarian trace elements and the body size of Atlantic cod Gadus morhua

2008 ◽  
Vol 65 (7) ◽  
pp. 1191-1197 ◽  
Author(s):  
A. Bang ◽  
P. Grønkjær ◽  
B. Lorenzen
Keyword(s):  
Trace Elements ◽  
Body Size ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
The Body ◽  
Small Fish ◽  
Female Size ◽  
Large Fish ◽  
Size Category ◽  
Linear Discriminant

Abstract Bang, A., Grønkjær, P., and Lorenzen, B. 2008. The relation between concentrations of ovarian trace elements and the body size of Atlantic cod Gadus morhua. – ICES Journal of Marine Science, 65: 1191–1197. Trace metals in the ovaries of fish are transferred from the female via the yolk to the offspring, which makes the early life stages susceptible to deleterious effects of potentially toxic elements contained in the ovaries. Here, the concentrations of 13 elements from the ovaries of 133 ripe female North Sea cod Gadus morhua weighing 0.2–18 kg were correlated with female size, accounting for differences in maturity and condition. Most elements were negatively correlated with the size variables weight, length and, especially, ovarian dry weight. Further, they were negatively correlated with maturity and condition. Many of the trace elements showed true size-dependence, but the correlations were generally weak. A linear discriminant analysis separated “small” and “large” fish at a length of 85 cm based on concentrations of Co, Mn, Se, and Zn, and correctly assigned 78 of 102 small fish and 23 of 31 large fish to their respective size category. This corresponds to an overall classification success of 75.9%. The results suggest that embryos and early larvae from small females are exposed to higher levels of potentially harmful metals. If the differences in trace element concentration influence survival success, this will add to the negative effects of size distribution truncation and declines in size-at-maturity experienced by many populations of cod.

DIPHYLLOBOTHRIUM INFECTION IN ESOX LUCIUS

1932 ◽  
Vol 6 (2) ◽  
pp. 166-170 ◽  
Author(s):  
Daniel Nicholson
Keyword(s):  
Esox Lucius ◽  
Intestinal Wall ◽  
Early Summer ◽  
Large Fish ◽  
Pike Esox Lucius

This study showed that most of the summer caught jackfish or pike (Esox lucius) contained many larvae of D. latum (plerocercoids), in contrast to the winter caught fish which showed a scanty infestation. The larvae in the winter caught fish were small and frequently motionless, while those in the summer caught fish were large and quite active.When dogs were fed motile larvae from winter caught fish, very few adult tapeworms developed. Sixty per cent of the larvae contained in the summer caught fish produced adult tapeworms. This suggests that D. latum infection of the Esox fish is probably an annual event occurring in the early summer months.It is the small to medium sized Esox that contain numerous D. latum parasites. The very large fish contained so few parasites as to suggest that after a period of development the D. latum larvae (plerocercoid) in the flesh of the fish die off and disintegrate leaving no trace of their presence, and as the fish become large the procercoid form of the parasite has difficulty in penetrating the intestinal wall of the fish.

Seasonal, Grazing Site and Fish Size Effects on Patterns of Algal Consumption by the Herbivorous Fish, Siganus rivulatus, at Mikhmoret (Mediterranean, Israel)

1993 ◽  
Vol 27 (7-8) ◽  
pp. 413-419 ◽  
Author(s):  
B. Lundberg ◽  
Y. Lipkin
Keyword(s):  
Late Summer ◽  
Food Composition ◽  
Mediterranean Coast ◽  
Medium Size ◽  
Limited Area ◽  
Small Fish ◽  
Large Fish ◽  
Food Species ◽  
The Difference ◽  
Siganus Rivulatus

Siqanus rivulatus, a successful herbivorous immigrant fish from the Red Sea, consumes along the Israeli east Mediterranean coast a wide variety of algae. Only four of them composed about a half of the bulk of its food, and only twelve, about 80% of it. Seasonal changes in quantitative representation of different algae in the food followed several patterns. Most algae were taken throughout the year. Proportions in the food of some algae fluctuated only slightly during the year, proportions of others were very great during short periods and much smaller during the rest of the year. Polvsiphonia is an example for the former, Ulva and Spatoglossum, for the latter. Among the latter, Ulva dominates the food contents during the end of winter and spring; Spatoglossum, during the late summer. As shown previously, s. rivulatus prefers certain algae as food. Nevertheless, food composition in fish captured at inshore sites differed from that of fish captured offshore. This reflects, to a certain extent, the difference in vegetation between these sites, and the fact that the fish tend to graze in a rather limited area at a time. Small and large fish take different algal food species. Unexpectedly, small fish clearly preferred some large and robust algae, consuming them in much greater proportions than bigger fish. Also unexpectedly, medium size fish showed preferences and avoidances of their own in regard to the consumption of certain algae, and not merely occupied an intermediate position between small and large fish.

The breeding of Crepidula fornicata (L.) in the River Blackwater, Essex

1951 ◽  
Vol 30 (1) ◽  
pp. 49-71 ◽  
Author(s):  
P. N. J. Chipperfield
Keyword(s):  
North America ◽  
New England ◽  
Detrimental Effect ◽  
Early Summer ◽  
Recent Discussion ◽  
Oyster Culture ◽  
Spawning Period ◽  
Crepidula Fornicata ◽  
Present Distribution ◽  
Male To Female

The chain-forming prosobranchiate gastropod Crepidula fornicata is not indigenous to British waters, but has been introduced during the last 70 or 80 years, probably from North America, upon imported oysters, and, during this period, has spread to most of the oyster beds on the south-east and south coasts of this country (see Orton, 1950b, for a recent discussion of its present distribution). In spite of the interest shown in this species because of its detrimental effect upon oyster culture, and because of its well-known change of sex from male to female, little is known in the literature of its breeding habits here, or in North America. Conklin (1897) states that the spawning period in New England lasts from early summer to about mid-August, no larvae being found in late August. Murie (1911), in discussing the introduction of this species, elaborates upon Conklin's observations, and gives evidence that females, in samples of Crepidula taken from the River Colne in May and September 1898, contained spawn beneath their shells. Orton (1912a, p. 438) states that he is ‘informed by Professor Conklin that American Crepidulae begin to spawn in May and possibly in April, whilst English Crepidulae begin to spawn in early March’. In a footnote, he adds ‘Crepidula spawned in tanks at Plymouth in early February’.

Size and Density Dependent Mating Tactics in the Simultaneously Hermaphroditic Seabass Serranus Subligarius (Cope, 1870)

Behaviour ◽  
1997 ◽  
Vol 134 (7-8) ◽  
pp. 563-594 ◽  
Author(s):  
Ann S. Oliver
Keyword(s):  
Mating Behavior ◽  
Evolutionarily Stable Strategy ◽  
Small Fish ◽  
Large Fish ◽  
Mating Tactics ◽  
Spawning Period ◽  
Female Pair ◽  
Fish Trade ◽  
Evolutionarily Stable ◽  
Daily Spawning

AbstractThis study examines factors within the mating system of Serranus subligarius (belted sandfish) that are likely to maintain simultaneous hermaphroditism as an evolutionarily stable strategy in a highly mobile, high density species. I focus on changes in mating behavior with size. Mating behavior was observed underwater in the northeastern Gulf of Mexico at St. Andrew Bay State Park. Every hermaphrodite can spawn in three roles over the course of the daily spawning period: female pair spawn, male pair spawn, and male streak spawn. Pair spawning fish trade eggs, taking turns fertilizing one another's eggs. Egg trading is not symmetrical; the smaller fish in a pair spawns more often in the female role than the larger fish. Overall, small fish ( 70 mm SL) pair spawn more frequently as females, while large fish ( 80 mm SL) pair spawn more often as males. A size advantage appears to exist for male function. However, large fish usually release at least one egg parcel per spawning

Biology of the Pacific Pomfret (Brama japonica) in the North Pacific Ocean

1993 ◽  
Vol 50 (12) ◽  
pp. 2608-2625 ◽  
Author(s):  
William G. Pearcy ◽  
Joseph P. Fisher ◽  
Mary M. Yoklavich
Keyword(s):  
Pacific Ocean ◽  
North Pacific ◽  
North Pacific Ocean ◽  
Gulf Of Alaska ◽  
Small Fish ◽  
Large Fish ◽  
The North ◽  
The Pacific ◽  
Subarctic Current ◽  
The North Pacific

Abundances of Pacific pomfret (Brama japonica), an epipelagic fish of the North Pacific Ocean, were estimated from gillnet catches during the summers of 1978–1989. Two size modes were common: small pomfret <1 yr old, and large fish ages 1–6. Large and small fish moved northward as temperatures increased, but large fish migrated farther north, often into the cool, low-salinity waters of the Central Subarctic Pacific. Lengths of small fish were positively correlated with latitude and negatively correlated with summer surface temperature. Interannual variations in the latitude of catches correlated with surface temperatures. Large catches were made in the eastern Gulf of Alaska (51–55°N) but modes of small pomfret were absent here, and large fish were rare at these latitudes farther to the west. Pomfret grow rapidly during their first two years of life. They are pectoral fin swimmers that swim continuously. They prey largely on gonatid squids in the region of the Subarctic Current in the Gulf of Alaska during summer. No evidence was found for aggregations on a scale ≤1 km. Differences in the incidence of tapeworm, spawning seasons, and size distributions suggest the possibility of discrete populations in the North Pacific Ocean.

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