Reproduction and Associated Behaviour in the Shorthorn Sculpin, Myoxocephalus scorpius in Newfoundland Waters

1970 ◽  
Vol 27 (11) ◽  
pp. 2037-2045 ◽  
Author(s):  
G. P. Ennis
Keyword(s):  
Embryonic Development ◽  
Water Column ◽  
First Generation ◽  
Egg Mass ◽  
Spawning Grounds ◽  
Spawning Area ◽  
Shorthorn Sculpin ◽  
Spawning Time ◽  
Myoxocephalus Scorpius ◽  
Newly Hatched Larvae

In Newfoundland waters, maturing ovaries of the shorthorn sculpin contain three generations of ova. Only the largest or ripe ova of the first generation are deposited at spawning time, which starts in late November or early December and lasts for about 1 month. It appears that only one male and one female participate in the spawning act and the eggs are laid in V-shaped crevices on rocky bottom at depths between 20 and 35 ft (6 and 11 m). The eggs adhere firmly to each other and the egg mass so formed adheres firmly to the bottom. After spawning, the spent females move from the spawning area to deeper water, but the males remain guarding the eggs until they hatch. At temperatures near 0 C embryonic development takes over 3 months to complete. Hatching starts around mid-March and lasts for 3–4 weeks. Newly hatched larvae occupy all layers of the water column over the spawning grounds but tend to concentrate near the bottom. Fecundity of mature females ranging in length from 20.1 to 50.5 cm ranges from 4205 to 60,976 eggs.

Food of Shorthorn Sculpin, Myoxocephalus scorpius, in the Cumberland Sound Area of Baffin Island

1974 ◽  
Vol 31 (3) ◽  
pp. 355-359 ◽  
Author(s):  
I. A. Moore ◽  
J. W. Moore
Keyword(s):  
Dry Weight ◽  
Abundant Species ◽  
The Other ◽  
Gut Contents ◽  
Baffin Island ◽  
Littorina Saxatilis ◽  
Shorthorn Sculpin ◽  
Cumberland Sound ◽  
Myoxocephalus Scorpius ◽  
Benthic Prey

One hundred shorthorn sculpins, Myoxocephalus scorpius, over 15 cm in length captured from June to October, 1972, in Cumberland Sound, Baffin Island, fed almost exclusively (90% by both numbers and dry weight) on the planktonic amphipods Pseudalibrotus glacialis and Parathemisto libellula. In contrast, 140 fish captured about the same times from nearby Pangnirtung Fjord fed heavily on the benthic gastropods Littorina saxatilis and Margarites umbilicalis (each 34% by numbers and 22% by weight) and the bivalve Modiolaria discors (16% by both). Drifting ice on Cumberland Sound probably reduced the level of illumination making the detection of benthic prey difficult and causing the sculpins in this area to feed entirely on the better illuminated, brightly colored plankton. At both localities, the most abundant species in the plankton and the epifauna were also the most frequently encountered in gut contents. On the other hand, coelenterates, planktonic gastropods, copepods, and infauna, all of which were abundant in the environment, were rarely eaten.

Age, Growth, and Sexual Maturity of the Shorthorn Sculpin, Myoxocephalus scorpius, in Newfoundland Waters

1970 ◽  
Vol 27 (12) ◽  
pp. 2155-2158 ◽  
Author(s):  
G. P. Ennis
Keyword(s):  
Growth Rates ◽  
Sexual Maturity ◽  
Average Length ◽  
Maximum Size ◽  
Age Group ◽  
Younger Age ◽  
Shorthorn Sculpin ◽  
Males And Females ◽  
The Difference ◽  
Myoxocephalus Scorpius

In Newfoundland waters, shorthorn sculpins, Myoxocephalus scorpius (L.), live to age 15 and attain a maximum size of just over 50 cm. The growth rates of males and females are little different below age 4, but above age 4 the females grow faster than the males, and the difference between average length-at-age for males and females gets progressively larger with age. Males mature at a younger age and at a smaller size than females. In any age-group where there are mature and immature individuals the mature ones are larger.

Feeding ecology of a common benthic fish, shorthorn sculpin (Myoxocephalus scorpius) in the high arctic

Polar Biology ◽  
2018 ◽  
Vol 41 (10) ◽  
pp. 2091-2102 ◽  
Author(s):  
Justin J. Landry ◽  
Aaron T. Fisk ◽  
David J. Yurkowski ◽  
Nigel E. Hussey ◽  
Terry Dick ◽  
...  
Keyword(s):  
Feeding Ecology ◽  
High Arctic ◽  
Benthic Fish ◽  
Shorthorn Sculpin ◽  
Myoxocephalus Scorpius

scholarly journals Sub-lethal effects of permethrin exposure on a passerine: implications for managing ectoparasites in wild bird nests

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Mariana Bulgarella ◽  
Sarah A Knutie ◽  
Margaret A Voss ◽  
Francesca Cunninghame ◽  
Brittany J Florence-Bennett ◽  
...  
Keyword(s):  
Liver Function ◽  
First Generation ◽  
Second Generation ◽  
Egg Mass ◽  
Bird Conservation ◽  
Nest Material ◽  
Water Control ◽  
Negative Effects ◽  
Lethal Effects ◽  
Treatment Benefits

Abstract Permethrin is increasingly used for parasite control in bird nests, including nests of threatened passerines. We present the first formal evaluation of the effects of continued permethrin exposure on the reproductive success and liver function of a passerine, the zebra finch (Taeniopygia guttata), for two generations. We experimentally treated all nest material with a 1% permethrin solution or a water control and provided the material to breeding finches for nest building. The success of two consecutive clutches produced by the parental generation and one clutch produced by first-generation birds were tracked. Finches in the first generation were able to reproduce and fledge offspring after permethrin exposure, ruling out infertility. Permethrin treatment had no statistically significant effect on the number of eggs laid, number of days from clutch initiation to hatching, egg hatch rate, fledgling mass or nestling sex ratio in either generation. However, treating nest material with permethrin significantly increased the number of hatchlings in the first generation and decreased fledgling success in the second generation. Body mass for hatchlings exposed to permethrin was lower than for control hatchlings in both generations, but only statistically significant for the second generation. For both generations, an interaction between permethrin treatment and age significantly affected nestling growth. Permethrin treatment had no effect on liver function for any generation. Permethrin was detected inside 6 of 21 exposed, non-embryonated eggs (28.5% incidence; range: 693–4781 ng of permethrin per gram of dry egg mass). Overall, results from exposing adults, eggs and nestlings across generations to permethrin-treated nest material suggest negative effects on finch breeding success, but not on liver function. For threatened bird conservation, the judicious application of this insecticide to control parasites in nests can result in lower nestling mortality compared to when no treatment is applied. Thus, permethrin treatment benefits may outweigh its sub-lethal effects.

Embryonic development and fecundity of the red deep-sea crab Chaceon quinquedens (Smith, 1879) (Decapoda: Brachyura: Geryonidae) in the Mid-Atlantic Bight determined by image analysis

2020 ◽  
Vol 40 (3) ◽  
pp. 230-236 ◽  
Author(s):  
Stephanie Martínez-Rivera ◽  
Bradley G Stevens
Keyword(s):  
Embryonic Development ◽  
Deep Sea ◽  
Development Stage ◽  
Egg Mass ◽  
Commercial Fishing ◽  
Imaging Method ◽  
Female Body Size ◽  
Fishing Vessels ◽  
The Us ◽  
Stage 1

Abstract The red deep-sea crab, Chaceon quinquedens (Smith, 1879), has been harvested from the US Atlantic continental shelf since the 1970s, but knowledge about its biology is extremely limited. We describe the stages and seasonality of embryonic development and determine size-specific fecundity for C. quinquedens in the Mid-Atlantic Bight. Samples were collected by trawling aboard research vessels in 2012–2013, and from traps aboard commercial fishing vessels in 2014–2016. Four stages of embryonic development were described: 1) early development, 2) mid-development, 3) late development, and 4) hatching. A relationship between embryonic development stage and egg-mass color was observed. A brooding cycle was proposed after analyzing seasonal changes in the stages of embryonic development. Fecundity was estimated by using an automated imaging method for egg samples during stage 1 and 2. The estimates of fecundity, the number of eggs per brood, ranged from 34,691 to 324,729 for females between 62.6 and 106.2 mm in carapace length (CL). The linear regression showed a positive correlation between fecundity and female body size in CL (R2 = 0.56). This study provides information on reproductive parameters needed to improve fisheries management.

The relationship between molecular weight and antifreeze polypeptide activity in marine fish

1986 ◽  
Vol 64 (3) ◽  
pp. 578-582 ◽  
Author(s):  
Ming H. Kao ◽  
Garth L. Fletcher ◽  
Nam C. Wang ◽  
Choy L. Hew
Keyword(s):  
Molecular Weight ◽  
Thermal Hysteresis ◽  
Freezing Temperature ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Molecular Weights ◽  
Shorthorn Sculpin ◽  
Myoxocephalus Scorpius ◽  
Antifreeze Peptides ◽  
Antifreeze Activity

Previous studies have established that the capacity of the glycopeptide antifreezes to depress the freezing temperature of aqueous solutions is positively correlated with molecular weight. The present study was carried out to determine whether a similar correlation existed within the antifreeze peptides. Two approaches were used. Initially, the antifreeze activity (thermal hysteresis) curves of antifreeze peptides from winter flounder, Pseudopleuronectes americanus (molecular weight, 3300), shorthorn sculpin, Myoxocephalus scorpius (molecular weight, 4000), ocean pout, Macrozoarces americanus (molecular weight, 6000), and sea raven, Hemitripterus americanus (molecular weight, 9700), were compared. In the second approach, a more specific comparison was made of two different sized antifreeze peptide components (molecular weights, 2900 and 4000) from the shorthorn sculpin. In both approaches, antifreeze peptide activity was positively correlated with molecular weight and the curve illustrating this relationship suggests that any reduction in molecular weight below 3300 will result in a disproportionate decline in activity. The relatively small antifreeze peptides from the winter flounder and shorthorn sculpin had greater activity than did glycopeptide antifreezes of similar size. However, glycopeptide antifreezes with a molecular weight of 10 000 or more had activities that exceeded that of any known antifreeze peptide. Increases in molecular weight of antifreeze peptides above 4000 resulted in a decline in antifreeze activity per milligram protein. Therefore, in terms of ability to depress the freezing temperature, there appears to be no advantage in evolving large antifreeze peptide molecules.

Sign in / Sign up

Export Citation Format

Share Document