Syngnathus Fuscus Research Articles

Northern pipefish, Syngnathus fuscus, occurrences over the Mid-Atlantic Bight continental shelf: evidence of seasonal migration

Data from several areas in the northern Mid-Atlantic Bight indicate northern pipefish, Syngnathus fuscus, undergo seasonal, inshore-offshore migrations. Resident in estuaries during spring through fall, they move into nearshore continental shelf waters off Cape Cod in late September–October and off Long Island and New Jersey in November. Return to estuaries occurs in March–April. Most (> 90%) continental shelf otter trawl collections in fall (September–November) were at water temperatures of 10–15°C. Most (> 80%) spring (March–May) collections occurred at water temperatures of 3–6°C. The majority of offshore collections were within 20 km of the coast and over 90% were in depths between 10 and 20 m. Length frequency data reveal both young-of-year and older fish migrate, possibly to avoid colder estuarine water temperatures in winter.

Pipefish foraging: effects of fish size, prey size and altered habitat complexity

Laboratory experiments determined the effects of 2 levels of habitat complexity upon pipefish Syngnathus fuscus foraging for amphipods. Habitats were composed of equal densities of either narrow (low complexity) or wide (high complexity) leafed artificial seagrass. Response to habitat as measured by rate of encounter with amphipods, probability of attack after encounter, probability of success after attack, and overall rate of amphipod consumption was determined for combinations of 2 fish size classes and 3 amphlpod size classes. Small fish did not respond to changes in habitat complexity, while large fish &d. Large fish encountered fewer amphipods in the high than in the low complexity habitat. In general encounter rate increased with amphipod size. Large fish attack probability was negatively related to amphipod size in the narrow leaf habitat, but positively related to amphipod size in the wide leaf habitat. Small fish attack probability was negatively related to amphipod size in both habitats. Success was negatively related to prey size and greater for large than for small fish. and showed no overall effect of habitat. The position that amphipods occupy in the structure of vegetation in part determines their vulnerability to predation, a criterion by which pipefish appear to select prey. In this respect pipefish behavior is flexible, allowing adjustment of foraging tactics to match habitat constraints. Results suggest that relative sizes of predator and prey are important factors in determining the effect of structural complexity upon predator-prey dynamics.

Feeding Ecology of the Northern Pipefish, Syngnathus fuscus, in a Seagrass Community of the Lower Chesapeake Bay

Examination of gut contents of the northern pipefish,Syngnathus fuscus, revealed that gammarid amphipods, caprellid amphipods, isopods, and calanoid copepods were the dominant food items during the sevenmonth study period.Gammarus mucronatus, calanoid copepods, andErichsonella attenuata were the seasonally dominant prey items in the spring, summer, and fall, respectively.G. mucronatus and calanoid copepods were consumed in approximate proportion to their numerical abundance in the environment, whileE. attenuata, present in rather uniform densities throughout the study period, was extensively consumed only in the late summer and fall. An ontogenetic pattern of prey consumption was evident, in addition to the seasonal pattern. Comparison ofG. mucronatus andE. attenuata size ranges from the field and in pipefish guts revealed thatS. fuscus preyed upon the smaller size classes of each species, and that mean size of prey consumed was positively related to fish size.

Feeding chronology, daily ration, and the effects of temperature upon gastric evacuation in the pipefish,Syngnathus fuscus

Feeding chronology, daily ration, and the effects of temperature upon gastric evacuation were examined in the pipefish,Syngnathus fuscus, from field and laboratory data.S. fuscus displayed a pattern of diurnal feeding, characteristic of syngnathids. Daily ration calculations yielded estimates of 4.0 and 4.4% body weight per day, which are comparable to estimates for other teleosts. Evacuation rate was found to be temperature dependent. with more rapid evacuation with increasing temperature. In addition, evacuation rate was found to be positively correlated with gut content. Slowing of evacuation rate with decreasing gut content may allow for increased assimilation efficiency during periods of low food availability. Daily ration, although controlled by the temperature dependence of evacuation rate, may also be controlled by prey abundance; fish maximize food intake during periods of high prey availability, and maximize upon assimilation during periods of low prey availability.

Permeability of the marsupium of the pipefish Syngnathus fuscus to [ 14C]-alpha amino isobutyric acid

1. 1. Male pipefish, Syngnathus fuscus, with embryos were injected with a radioactively labelled non-metabolizable amino acid and accumulation of the acid monitored in the developing embryos. 2. 2. Evidence is presented for the transfer of the amino acid from paternal tissue to developing young.

Structural Components of Eelgrass (Zostera marina) Meadows in the Lower Chesapeake Bay: Fishes

The structure of the fish community associated with eelgrass beds in the lower Chesapeake Bay was studied over a 14 month period. A total of 24,182 individuals in 48 species was collected by otter trawl with Leiostomus xanthurus (spot) comprising 63% of the collection, Syngnathus fuscus (northern pipefish) 14%, Anchoa mitchilli (bay anchovy) 9%, and Bairdiella chrysoura (silver perch) 5%. The density and diversity of fishes were higher in vegetated areas compared to unvegetated areas; fishes were more abundant in night collections Fish abundance and species number increased in the spring and early summer as both water temperature and eelgrass biomass increased and decreased in the fall and winter as temperature and eelgrass biomass decreased. Gill netting revealed some of the top predators in the system, especially the sandbar shark, Carcharhinus milberti. The fish community in the Chesapeake Bay was quite different from North Carolina eelgrass fish communities. Most notable was the rarity of the pinfish, Lagodon rhomboides, which may be a very important predator in the structuring of the epifaunal communities.

Cortical alveoli formation and vitellogenesis during oocyte differentiation in the pipefish, Syngnathus fuscus, and the killifish, Fundulus heteroclitus.

AbstractThe formation of cortical alveoli and yolk has been investigated in the pipe‐fish, Syngnathus fuscus, and the killifish, Fundulus heteroclitus by techniques of light and electron microscopy. In addition to cortical alveoli and yolk components the ooplasm contains many mitochondria, numerous Golgi complexes, copious quantities of the endoplasmic reticulum of the rough variety, ribosomes and particulate glycogen. While the formation of cortical alveoli and yolk may proceed simultaneously, the cortical alveoli are the first to develop. Staining procedures indicate that cortical alveoli, like some of the yolk bodies contain a polysaccharide component and protein. It is suggested that the protein portion is made by the endoplasmic reticulum and is subsequently transferred to the Golgi complex via vesicles. Within the saccules of the Golgi complex the polysaccharide component is fabricated after which time the Golgi produce vesicles containing the products of either the cortical alveoli or yolk bodies.The precursors used in the production of the yolk are produced by the oocyte (endogenous) and by an organ other than the ovary (exogenous). The precursors made exogenously become associated with the morphologically and physiologically specialized oolemma and are subsequently internalized by the process of micropinocytosis.

The formation of the primary envelope during oocyte differentiation in teleosts.

The differentiation of the primary envelope of oocytes of the seahorse (Hippocampus erectus) and the pipefish (Syngnathus fuscus) has been investigated by techniques of light- and electron microscopy. The developing oocytes have been divided into four stages according to size. Oogonia are designated as stage I; stages II and III are oocytes; stage IV represents mature eggs. The primary envelope which is produced by the oocyte is initially a tripartite structure; for convenience of description, the portions are referred to as zones 1, 2, and 3, respectively. Zone 1 first appears as a homogeneous substance at approximately the middle of the long axis of each microvillus. Zone 2 is immediately beneath zone 1 and consists of an extremely electron-opaque granular component. Zone 3 is subjacent to zone 2; it is the largest and most complex of the three. Zone 3 consists of an amorphous material organized in a reticular-like network. Staining procedures indicate that the envelope is composed of a glycoprotein. Just before the oocyte matures there is a structural alteration in zones 2 and 3. Zone 2 becomes a compact, dense layer and zone 3 becomes multilaminate. Subsequent to these changes, zone 1 degenerates. The classification of egg envelopes is discussed, and comparisons are made between the primary envelope of the teleosts investigated and the primary envelopes of other species.

Silverside, Menidia menidia, and Northern Pipefish, Syngnathus fuscus, in the St. John River, N.B.

Silverside, Menidia menidia, and Northern Pipefish, Syngnathus fuscus, in the St. John River, N.B.

Planktonic Fish Eggs and Larvae of Sandy Hook Estuary

Twenty species of planktonic fish eggs and larvae were identified from 75 surface plankton tows made at river, bay, and ocean locations in the Sandy Hook estuary. A gradual increase in the number of species through the spring to a peak in the summer was followed by a decline in the fall and winter. Seventeen species were collected at a location where the Navesink River joins with Sandy Hook Bay. Seven species: American eel, Atlantic herring, American sand lance, winter flounder, bay anchovy, northern pipefish, and Atlantic silverside made up 98$ of all larvae collected. Winter flounder were most ubiquitous and exhibited a marked diel variation in abundance. The most abundant eggs were those of searobin and Atlantic menhaden. Larvae of several species were collected whose adults are either summer or winter visitors to inshore waters.

STUDIES ON THE LIFE HISTORY OF ANISOPORUS MANTERI HUNNINEN AND CABLE, 1940 (TREMATODA : ALLOCREADIIDAE)

The life history of Anisoporus manteri Hunninen and Cable, 1940, has been traced experimentally. The cercaria, a cotylomicrocercous type, develops in sporocysts in the marine snail, Mitrella lunata (Say) and encysts in the marine amphipods, Carinogammarus mucronatus (Say) and Amphithoë longimana Smith. Old metacercariae contain eggs in the uterus and cystic fluid. Adult worms occur in the intestine of the marine fishes, Syngnathus fuscus Storer, Paralichthys dentatus (Linnaeus), Hippoglossoides platessoides (Fabricius), Apeltes quadracus (Mitchill), Fundulus heteroclitus (Linnaeus) and F. majalis (Walbaum).It is proposed that the family Allocreadiidae be restricted to include only trematodes having cotylomicrocercous cercariae and simplified excretory patterns, since the type genus, Allocreadium, would be included in the restricted family. Consequently, the family name, Opecoelidae, would be suppressed as a synonym of Allocreadiidae sensu stricto.

An intermediate stage in the development of the skull of syngnathus fuscus

An intermediate stage in the development of the skull of syngnathus fuscus