Sex steroid levels in the testes, ovaries, and pyloric caeca during gametogenesis in the sea star Asterias vulgaris

We performed a factorial experiment to investigate the effects of current and prey odours (mussels) on the displacement behaviour of the sea star Asterias vulgaris (Verrill, 1866). This sea star is a common subtidal predator of sessile and slow-moving animals in the western North Atlantic Ocean. In the presence of current and prey odours in a flume, sea stars oriented themselves upstream and 70% succeeded in finding the prey. Also, the degree of orientation toward the prey increased as the sea star approached the prey. In contrast, only 5% of individuals tested in still water found the prey. Thus, for A. vulgaris the presence of macroscale flow is an essential condition for locating distant prey. Sea stars tested in current alone showed rheotactic behaviour, moving diagonally upstream. This behaviour should enhance the probability of encountering prey odour plumes in the field. Sea stars moved faster and straighter in flowing water than in still water. The slow movement of A. vulgaris in still water probably minimizes costs of foraging when there is a low chance of finding prey and the straight diagonal movement in current should ensure that the sea star continuously samples new areas, rather than resampling the same odour-free area.

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Time-course and dose-response of the apparent induction of the cytochrome P450 monooxygenase system of pyloric caeca musomes of the female sea star Asterias rubens L. by benzo[a]pyrene and polychlorinated biphenyls

Aquatic Toxicology ◽

10.1016/0166-445x(93)90003-j ◽

1993 ◽

Vol 26 (1-2) ◽

pp. 23-39 ◽

Cited By ~ 35

Author(s):

P.J. den Besten ◽

P. Lemaire ◽

D.R. Livingstone ◽

B. Woodin ◽

J.J. Stegeman ◽

...

Keyword(s):

Cytochrome P450 ◽

Polychlorinated Biphenyls ◽

Dose Response ◽

Time Course ◽

Cytochrome P450 Monooxygenase ◽

Monooxygenase System ◽

Sea Star ◽

Asterias Rubens ◽

P450 Monooxygenase ◽

Pyloric Caeca

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Activities of hexokinase, phosphofructokinase and pyruvate kinase in the body wall, pyloric caeca and tube feet of Asterias vulgaris: Evidence of body wall as a major source of glycolytic activity

Comparative Biochemistry and Physiology Part B Comparative Biochemistry ◽

10.1016/0305-0491(89)90343-x ◽

1989 ◽

Vol 94 (2) ◽

pp. 263-267 ◽

Cited By ~ 1

Author(s):

Naoyuki Saito ◽

Stephen A. Watts

Keyword(s):

Pyruvate Kinase ◽

Body Wall ◽

The Body ◽

Pyloric Caeca ◽

Glycolytic Activity ◽

Asterias Vulgaris ◽

Tube Feet

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Use of a wave tank to study the effects of water motion and algal movement on the displacement of the sea star Asterias vulgaris towards its prey

Marine Ecology Progress Series ◽

10.3354/meps258125 ◽

2003 ◽

Vol 258 ◽

pp. 125-132 ◽

Cited By ~ 22

Author(s):

P Gagnon ◽

G Wagner ◽

JH Himmelman

Keyword(s):

Sea Star ◽

Wave Tank ◽

Water Motion ◽

Asterias Vulgaris

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Reproductive biology and energetics of the brooding sea star Anasterias antarctica (Echinodermata: Asteroidea) in the Beagle Channel, Tierra del Fuego, Argentina

Revista de Biología Tropical ◽

10.15517/rbt.v65i1-1.31690 ◽

2017 ◽

Vol 65 (1-1) ◽

pp. 221 ◽

Cited By ~ 3

Author(s):

Analía F. Pérez ◽

Cintia Fraysse ◽

Claudia C. Boy ◽

Lucia Epherra ◽

Calcagno Javier

Keyword(s):

Tierra Del Fuego ◽

Sea Star ◽

Reproductive Condition ◽

Sea Stars ◽

Pyloric Caeca ◽

Beagle Channel ◽

Brooding Period ◽

Wet Weight ◽

Sexually Mature

The brooding sea star Anasterias antarctica is distributed from the coast of Patagonia to the northern Peninsula of Antarctica. In the Beagle Channel, the females of A. antarctica brood their eggs for seven months and do not feed during this period. The endoparasite Dendrogaster argentinensis (Crustacea: Ascothoracica) causes castration in several species of Anasterias. We randomly collected four samplings of adults in May, August and October (brooding period) and January (non-brooding period). The gonad (GI) and pyloric caeca index (PCI) were calculated as organ wet weight (g) x 100/total wet weight (g). Each individual was sexed by microscopic examination of the gonads. Sex ratio, brooding females/non-brooding females and mature females/non-mature females ratios was 1:1. The male GI reached maximum values in January, when most individuals were sexually mature. The GI of non-brooding females reached its maximum during October when it was significantly higher than those from brooding females. The PCI was minimum in October, being lower in brooding females (August and October). During the non-brooding period, mature females had a significantly higher GI than non-mature females. The PCI did not vary neither between males, nor between mature and non mature females. By the end of the brooding period, non-brooding females showed a higher GI than the brooding females. This is explained by proliferation and increase of the oocytes size of non-brooding females. Mature females showed an incremented GI with presence of mature oocytes, while non-mature females exhibited more abundance of previtelogenic oocytes. Males showed synchronicity in reproductive condition. The females that have not brooded presented a process of active gametogenesis, reaching the summer with a high GI, therefore becoming mature females. Females that had brooded were probably lacking energy for new gonadal maturation. The pyloric caeca would be performing the role of a reserve organ in the brooding females, decreasing its size during the brooding period. Prevalence of D. argentinensis in A. antarctica was 11.06%. As this parasite was recorded in sea stars lacking gonads, these infected hosts could have been castrated. Rev. Biol. Trop. 65(Suppl. 1): S221-S232. Epub 2017 November 01.

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