Matrix Analysis of Co-occurrences of Fishes of the Scotian Shelf and Bay of Fundy

1989 ◽  
Vol 46 (2) ◽  
pp. 191-197 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Shallow Water ◽  
Species Abundance ◽  
Matrix Analysis ◽  
Bay Of Fundy ◽  
Trawl Survey ◽  
Scotian Shelf ◽  
Sea Raven ◽  
Longhorn Sculpin ◽  
Silver Hake ◽  
Shallow Water Species

Numbers of co-occurrences of 29 common fishes of the Bay of Fundy and Scotian Shelf were derived from annual research trawl survey data for the summers of 1970–79 and the spring, summer, and autumn seasons of 1980–84. Matrices prepared from the data were used to examine degrees of association between different species and seasonal and geographical variation in the associations. Three categories of associations were identified: shallow water with a dominant winter flounder (or yellowtail flounder) – longhorn sculpin – sea raven assemblage; middepth with a dominant cod – haddock – thorny skate assemblage; deepwater characteristic species but with no strong recurring assemblages. Strength of co-occurrence was directly related to species abundance and changes corresponded to known seasonal movements in several species, including silver hake, spiny dogfish, and pollock. In general, the strength and number of co-occurrences decreased from southwest to northeast along the Scotian Shelf. The Bay of Fundy was exceptional, with strong co-occurrences of shallow-water species and poor representation of deepwater fishes.

Parasitic protozoa from marine and euryhaline fish of Newfoundland and New Brunswick. I. Peritrichous ciliates

1969 ◽  
Vol 47 (6) ◽  
pp. 1367-1380 ◽  
Author(s):  
Jiří Lom ◽  
Marshall Laird
Keyword(s):  
New Brunswick ◽  
Marine Fish ◽  
Bay Of Fundy ◽  
Euryhaline Fish ◽  
Sea Raven ◽  
Ecological Vulnerability ◽  
High Incidence ◽  
Shorthorn Sculpin ◽  
Longhorn Sculpin ◽  
Environmental Tolerances

Trichodina elizabethae n. sp. (which is commonly hyperparasitized by the suctorian Endosphaera engelmanni Entz), T. galyae n. sp., and T. domerguei (Wallengren) saintjohnsi n. subsp. are described from Newfoundland waters; the first two from the radiated shanny and lumpfish respectively, and the last from the mailed sculpin, lumpfish, and shorthorn sculpin. T. jarmilae n. sp. parasitizes the sea raven in the Bay of Fundy, New Brunswick. In both provinces, T. cottidarum Dogiel, sensu lato, occurs on shorthorn and longhorn sculpins. Two species of fish from brackish pools (the threespine stickleback in both areas; the mummichog in the Bay of Fundy) are often heavily parasitized by T. tenuidens Fauré-Fremiet. All the ciliates referred to were collected from the gills of their hosts, only two of which bore peritrichs other than trichodinids. One of these, Caliperia brevipes Laird, is found on the little skate in the Bay of Fundy and has been described elsewhere. The other, Scyphidia arctica Zhukov, is now reported from the longhorn sculpin in Newfoundland. Only five (16%) of 31 species of marine fish from Newfoundland bore trichodinids, as compared with nine (35%) of 26 from New Brunswick. However, four of the latter group had extremely light or sporadic infestations. Three of the rest, showing high incidence and heavy to extremely heavy infestations, were sculpins (Cottidae), as were three of the five Newfoundland hosts. Thus, while information is accumulating to suggest that marine fish trichodinids find optimum environmental conditions where mean seawater temperatures are not extreme (neither very warm nor very cold), certain fish are evidently more prone to infestation than others. This may well be due to varying ecological vulnerability to parasitization rather than to the operation of host specificity, an important question which, like that of environmental tolerances, merits early experimental attention. The paper includes a list of 61 species of Trichodina and the closely related Tripartiella and Trichodinella now known from marine and euryhaline fish, their validity being assessed on the basis of technique and the taxonomic criteria used.

Selection of Bottom Type by Groundfishes of the Scotian Shelf

1982 ◽  
Vol 39 (7) ◽  
pp. 943-947 ◽  
Author(s):  
J. S. Scott
Keyword(s):  
Shallow Water ◽  
Sediment Type ◽  
Scotian Shelf ◽  
Bottom Type ◽  
Sediment Particle Size ◽  
Deep Water Species ◽  
Sand And Gravel ◽  
Shallow Water Species ◽  
Water Species ◽  
Selection Of

Catches (numbers per tow) of 25 species of groundfish of the Scotian Shelf were estimated for five different bottom types on which the tows were made. An index of selectivity was calculated for each species. Selectivity ranged from highly specific in shallow-water species on sand and gravel bottom, to broad in deep-water species associated mainly with mud and silt bottoms, and in semipelagic species. Gradation in bottom-sediment particle size from northeast to southwest is correlated with clines in shallow-water fish abundance. Bottom type and water depth are correlated with each other and with fish distribution.Key words: bottom type, groundfish, sediment type

Median length at sexual maturity of halibut, cusk, longhorn sculpin, ocean pout, and sea raven in the Maritimes area of the Northwest Atlantic

1982 ◽  
Vol 60 (6) ◽  
pp. 1326-1330 ◽  
Author(s):  
Terry D. Beacham
Keyword(s):  
Sexual Maturity ◽  
Scotian Shelf ◽  
Median Length ◽  
Hippoglossus Hippoglossus ◽  
Northwest Atlantic ◽  
Sea Raven ◽  
Longhorn Sculpin ◽  
Hemitripterus Americanus

The length at which 50% of the individuals were mature was calculated for some Northwest Atlantic groundfish species. Median length at maturity for halibut (Hippoglossus hippoglossus) on the Scotian Shelf declined from 84 cm for males during 1959–1964 to 66 cm during 1970–1979. Median lengths at maturity for females declined from 98 to 70 cm. Ranges of median lengths (centimetres) at maturity for other species were as follows: cusk (Brosme brosme), male 48–56, female 47–56; longhorn sculpin (Myoxocephalus octodecemspinosus), male 24–29, female 23–25; ocean pout (Macrozoarces americanus), male 45, female 28; and sea raven (Hemitripterus americanus), male 36, female 28.

Corynosoma wegeneri (Acanthocephala: Polymorphida) and Pseudoterranova decipiens (Nematoda: Ascaridoidea) Larvae in Scotian Shelf Groundfish

1992 ◽  
Vol 49 (10) ◽  
pp. 2062-2069 ◽  
Author(s):  
David J. Marcogliese ◽  
Gary McClelland
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Host Record ◽  
Melanogrammus Aeglefinus ◽  
Scotian Shelf ◽  
New Host ◽  
New Host Record ◽  
Pseudoterranova Decipiens ◽  
Sea Raven ◽  
Longhorn Sculpin

We examined larvae of the seal parasites Corynosoma wegeneri and Pseudoterranova decipiens in various fish species collected from Western and Sable Island banks between February 1989 and October 1990. Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), American plaice (Hippoglossoides platessoides), yellowtail flounder (Pleuronectes ferrugineus), windowpane (Scophthalmus aquosus), longhorn sculpin (Myoxocephalus octodecemspinosus), and sea raven (Hemitripterus americanus) were infected by both parasites, longhorn sculpin being a new host record for C. wegeneri. Only C. wegeneri occurred in winter flounder (Pleuronectes americanus), and neither parasite was found in northern sand lance (Ammodytes dubius) or capelin (Mallotus villosus). The two parasites were most numerous in sea raven and longhorn sculpin. Corynosoma wegeneri was more prevalent in fish sampled in 1989–90 than in previous surveys of Atlantic cod and haddock from the Scotian Shelf. Pseudoterranova decipiens and C. wegeneri occurred throughout the sampling area, but small fishes in the vicinity of Sable Island had the heaviest sealworm infections, and both parasites in longhorn sculpin declined with distance from Sable Island. Increases of C. wegeneri in groundfish, like recent increased levels of P. decipiens infection on the Scotian Shelf, can be attributed to the dramatic growth of the grey seal (Halichoerus grypus) population on Sable Island.

A new shallow water species of Artemisina Vosmaer, 1885 (Microcionidae, Demospongiae; Porifera) from Northeastern Brazil

Zootaxa ◽  
2016 ◽  
Vol 4184 (2) ◽  
pp. 386 ◽  
Author(s):  
THAYNÃ CAVALCANTI ◽  
GEORGE GARCIA SANTOS ◽  
EDUARDO HAJDU ◽  
ULISSES PINHEIRO
Keyword(s):  
Shallow Water ◽  
Northeastern Brazil ◽  
Shallow Water Species ◽  
Water Species

Seasonal and Geographic Variation in the Species Composition and Size of Prey Consumed by Grey Seals (Halichoerus grypus) on the Scotian Shelf

1993 ◽  
Vol 50 (8) ◽  
pp. 1768-1778 ◽  
Author(s):  
W. D. Bowen ◽  
J. W. Lawson ◽  
B. Beck
Keyword(s):  
Atlantic Cod ◽  
Halichoerus Grypus ◽  
Scotian Shelf ◽  
Sand Lance ◽  
Atlantic Mackerel ◽  
Relative Contribution ◽  
Wet Weight ◽  
The Mean ◽  
Silver Hake ◽  
Commercial Size

The grey seal (Halichoerus grypus) population on the Scotian Shelf has grown significantly over the past 20 yr, thus increasing the potential for competitive interactions between grey seals and fisheries. The relative contribution (percent wet weight) and size of prey eaten were estimated from otoliths and squid beaks recovered from 143 stomachs that contained food of the 528 collected from 1988 to 1990. Although 22 taxa were found, only four species (Atlantic herring, silver hake, Atlantic cod, and squid) accounted for 80% of the estimated weight of food eaten. The mean length of prey eaten ranged from 19 to 35 cm for six species. Only 17% of the cod and none of the pollock and squid eaten were of the length taken in commercial fisheries. However, about 80% of the silver hake and herring eaten were of commercial size. Offshore at Sable Island, northern sand lance, silver hake, and squid (in order of importance) accounted for 86.1% of the wet weight ingested by seals during summer; sand lance and cod accounted for 96.1% of prey eaten in winter. At inshore locations, herring, cod, and pollock made up 90% of the diet in summer; Atlantic mackerel, cod, squid, and herring made up 83% of the diet in winter.

Relevance of an integrative approach for taxonomic revision in sponge taxa: case study of the shallow-water Atlanto-Mediterranean Hexadella species (Porifera:Ianthellidae:Verongida)

2012 ◽  
Vol 26 (3) ◽  
pp. 230 ◽  
Author(s):  
Julie Reveillaud ◽  
Céline Allewaert ◽  
Thierry Pérez ◽  
Jean Vacelet ◽  
Bernard Banaigs ◽  
...  
Keyword(s):  
Shallow Water ◽  
Phylogenetic Reconstruction ◽  
Taxonomic Revision ◽  
Integrative Approach ◽  
Cryptic Species Complex ◽  
Surface Network ◽  
Natural Toxicity ◽  
Shallow Water Species ◽  
Water Species

The identification of sponges that lack a mineral skeleton is always highly challenging, especially for Hexadella species, which are also fibreless. Recently, the yellow species Hexadella pruvoti Topsent was identified as a cryptic species complex while the pink coloured Hexadella racovitzai Topsent showed two highly divergent lineages. We performed a COI phylogenetic reconstruction using 27 new Mediterranean Hexadella samples in order to confirm the presence of divergent lineages within both shallow-water species. Specimens were described with an integrative approach combining morphological and cytological investigations, biochemical profiling and assessment of natural toxicity in order to identify diagnostic characters for each taxon. H. topsenti, sp. nov. is distinguished from H. racovitzai by its colour, its surface network shape, divergent secondary metabolite patterns and toxicity values. H. crypta, sp. nov. differs from H. pruvoti by a different encrusting growth form when alive, and by distinctively colouring the ethanol fixative solution. In addition, H. pruvoti and H. crypta show different types of cells with inclusions as well as distinct metabolic fingerprints. Natural toxicity values, however, do not permit the separation of H. pruvoti and H. crypta. Our work shows that only the use of a combination of complementary tools can provide relevant descriptions for some problematic taxa.

Tanaidacea (Crustacea: Peracarida) from Japan. IV. Shallow-water species from Akajima with notes on the recolonization potential of tanaids

Zootaxa ◽  
2008 ◽  
Vol 1678 (1) ◽  
pp. 1 ◽  
Author(s):  
KIM LARSEN ◽  
MICHITAKA SHIMOMURA
Keyword(s):  
Phylogenetic Analysis ◽  
Shallow Water ◽  
New Genus ◽  
Abundant Species ◽  
Two New Species ◽  
Sandy Habitat ◽  
Nansei Islands ◽  
Shallow Water Species ◽  
Water Species ◽  
Preliminary Phylogenetic Analysis

Two new species of tanaids were collected from colonization traps deployed in a shallow water, sandy habitat off Akajima, Nansei Islands. One new parapseudidaen, Parapseudes arenamans, and one new nototanaidaen genus and species, Paranesotanais longicephalus, are described herein. A preliminary phylogenetic analysis of the closest genera confirms the validity of the new genus and suggests a close affinity between the Leptocheliidae and Nototanaidae. Paranesotanais longicephalus was by far the most abundant species in the habitat. Parapseudes arenamans is faster in colonization of vacant substrate (opportunistic species), while being an inferior competitor to Paranesotanais longicephalus later in succession. A key to Nesotanais and Paranesotanais is provided.

scholarly journals Fossil and modern sponge fauna of southern Australia and adjacent regions compared: interpretation, evolutionary and biogeographic significance of the late Eocene ‘soft’ sponges

2016 ◽  
Vol 85 (1) ◽  
pp. 13-35 ◽  
Author(s):  
Magdalena Łukowiak
Keyword(s):  
New Zealand ◽  
Shallow Water ◽  
Environmental Context ◽  
Late Eocene ◽  
Shallow Marine ◽  
Marine Communities ◽  
Shallow Water Species ◽  
Water Species

The late Eocene ‘soft’ sponge fauna of southern Australia is reconstructed based on disassociated spicules and is used to interpret the paleoecology and environmental context of shallow marine communities in this region. The reconstructed sponge association was compared with coeval sponge assemblages from the Oamaru Diatomite, New Zealand, and with the modern ‘soft’ sponge fauna of southern coastal of Australia. Based on the predominance of shallow- and moderately shallow-water species, the late Eocene assemblage is interpreted to have inhabited waters depths of about 100 m. This contrast with the spicule assemblage from New Zealand, which characterized deeper waters based on the presence of numerous strictly deepwater sponge taxa, and the absence of spicules of shallow-water demosponges represented in the Australian material. The southern Australian Eocene sponge assemblages have clear Tethyan affinities evidenced by the occurrence of sponges known today from diverse regions. This distribution suggests much wider geographical ranges of some sponge taxa during the Eocene. Their present distributions may be relictual. The modern sponge fauna inhabiting southern Australian waters shows only moderate differences from these of the late Eocene. Differences are more pronounced at lower taxonomic levels (family and genus).

Environmental versus genetic causes of morphologic variability in bryozoan colonies from the deep sea

Paleobiology ◽  
1976 ◽  
Vol 2 (2) ◽  
pp. 156-165 ◽  
Author(s):  
Thomas J. M. Schopf
Keyword(s):  
Shallow Water ◽  
Deep Sea ◽  
Fossil Record ◽  
Water Regime ◽  
Level Population ◽  
Total Variance ◽  
Genetic Causes ◽  
Single Genotype ◽  
Shallow Water Species ◽  
Water Species

Bryozoans are colonial animals and this permits the partitioning of their morphologic variability into components of within colony (i.e. within a single genotype) and between colony (i.e. between genotype) variance. These data have been obtained for four species of the endemic deep-sea genus Euginoma for a series of characters. In 8 comparisons, one component of the total variance dominated at the 5% level. Population (between colony) variance contributed significantly to the total variance in 63% of the comparisons (5 of 8); individual (within colony) variance contributed significantly to the total variance in 37% of the comparisons (3 of 8).Compared to shallow water species, the surprising feature of the deep-sea data is that the between colony component of variance is as high as it is. Possibly in the more stable, deep-sea environment, the genotypic contribution to the variance of each individual colony is expressed to a greater degree than in the more variable, shallow water regime. If so, then analyses of variability in colonial animals may be an independent means of ascertaining stability gradients in the fossil record.

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