Richard A. Boolootian

ON THE REPRODUCTIVE CYCLE AND BREEDING HABITS OF TWO WESTERN SPECIES OF HALIOTIS

The genus Haliotis (Linnaeus) is composed of some 75 species distributed throughout the world. Members of this genus occur from subarctic to antarctic waters, but they are most abundant in temperate and tropical waters as common inhabitants of rocky intertidal and subtidal zones. Because these animals have been of commercial value since ancient times much has been written about their natural history, beginning with Aristotle (see Crofts, 1929). Chance observation of spawning and sporadic examination of the condition of gonads have been recorded by many investigators and fisheries biologists. However, no systematic investigation has been made of the, reproductive cycle and breeding habits of haliotids, except for the recent study of gametogenesis in H. lamellosa from the Mediterranean Sea (Bolognari, 1954). In the present study, changes in the size of Haliotis cracherodii and H. rufescens gonads relative to body size were followed throughout the year.

COELOMIC CORPUSCLES OF ECHINODERMS

1. The cellular elements from the body fluid of 15 different species of echinoderms were studied by phase contrast microscopy. Thirteen types of corpuscular elements were identified and the distribution, properties, characteristics and, where possible, functions, were determined.2. Some types of coelomocytes were observed in the species examined here which had not been previously described, e.g. the red corpuscles of the sand dollar and crinoid, and the lobular corpuscles of the crinoid. Some of the coelomocytes formerly described were also found in the species described. Among these are the controversial bladder amebocytes in which the presence of bladder has been questioned. Present studies verify the bladders as real structures easily seen in three dimensions. The bladder amebocyte undergoes a transformation into the filiform amebocyte which represents a pre-coagulation change.3. A greater diversity of cell types was observed in the body fluid of the more highly specialized forms such as the echinoids ...

ORGANIC PRODUCTIVITY IN THE REPRODUCTIVE CYCLE OF THE PURPLE SEA URCHIN

1. Monthly determinations were made of the amount of lipid, glycogen, nonprotein nitrogen, protein, water, and ash present per unit weight in gonads of the purple sea urchin, Strongylocentrotus purpuratus. Tests for reducing sugar, DNA and RNA were made for gonads at the height of the reproductive season and after spawning-out.2. A change in relative proportions of the chemical constituents was observed with maturation of the gonads. In the ovary protein, lipid, glycogen, reducing sugar and RNA increase proportionally more than the over-all increase in bulk of the gonad, while DNA and possibly water, increase proportionally less. In the testis, glycogen, reducing sugar, DNA and possibly protein, increase proportionally more than the over-all increase in bulk, while RNA, lipid, and possibly water, increase less than the increase in total bulk.3. A considerable increase in the total amount of all the organic constituents tested here occurs during the growth of gonads. Thus, a gravid ovary is about 18.5 time...

Digestion of brown algae and the distribution of nutrients in the purple sea urchin Strongylocentrotus purpuratus

Abstract 1. 1. The purple sea urchin Strongylocentrotus purpuratus digests the brown algae Macrocytis pyrifera and Egregia Laevigata with high efficiency, averaging 80 per cent digested for the former and 62 per cent for the latter. The brown algae Petalonia fascia and Halidrys dioica are not the usual diet of this animal and are digested with lower efficiencies, 50 and 44 percent respectively. 2. 2. When digestive efficiencies during continual feeding are compared with those after a single feeding, there appears to be little difference between them. 3. 3. Macrocystis labeled with C 14 was fed to S. purpuratus and the time of appearance and distribution of C 14 were subsequently examined. Within a few hours the plasma of the perivisceral fluid becomes radioactive with a soluble product of digestion which proved to be mannitol, a sugar alcohol which comprises 30 per cent of the algas dry weight (ash-free). Peaks of radioactivity in the plasma appear as often as radioactive meals are offered to the urchin. Over longer periods the C 14 is concentrated chiefly in the first and second circuits of the intestine, but incorporation of C 14 into the gonads occurs much more slowly. 4. 4. The red and white coelomocytes of the perivisceral fluid become radioactive later than the plasma. A high specific activity is reached and maintained in the red coelomocytes hours after the radioactive meal. The number of red coelomocytes in the perivisceral fluid fluctuates, suggesting that these cells may be migrating into and out of the perivisceral fluid. 5. 5. A chemical test for glycogen shows that the red coelomocytes are rich in this polysaccharide in well-fed urchins. 6. 6. Injection of radioactive red coelomocytes into the perivisceral fluid of a non-radioactive urchin results in a distribution of the radioactivity into the tissues of the chemical. 7. 7. Evidence is presented of hitherto unknown connections of the hemal system between the gonads and intestines. These connections are filled with re coelomocytes. 8. 8. It is suggested that the hemal system may represent a true ciculatory system in the sea urchin S. purpuratus and that the red coelomocytes distribute products of digestion throughout the body by this system.

A CONTRIBUTION TO THE BIOLOGY OF A DEEP SEA ECHINOID, ALLOCENTROTUS FRAGILIS (JACKSON)

1. Following a chance collection of a deep sea urchin, Allocentrotus fragilis, from a depth of 80 fathoms, it subsequently became possible to collect the urchins on numerous occasions from the same area.2. The area of the bed was determined by grid dredging and the nature of the habitat determined to be relatively flat, gravel and sand underlaid with gray silt containing organic detritus and microscopic organisms.3. The deep sea urchin appears to graze on the bottom since the organisms and organic debris of the bottom sediment appear in little pellets in its gut.4. Many types of invertebrates are associated with Allocentrotus, including various other echinoderms. A variety of fishes is found as well.5. Individuals with mature gametes were obtained in February and March of 1957 and during the period of September, 1957 to January, 1958. Spawn-out appeared to occur between February and March during both years.6. Attempts to correlate the life cycle of Allocentrotus with various environmental factors led to t...

A Primitive Heart in the Echinoid Strongylocentrotus purpuratus

A pulsating vessel and a compartmented contractile chamber have been found to move coelomic fluid from the perivisceral cavity into and throughout the hemal system of the sea urchin, Strongylocentrotus purpuratus.

ANNUAL REPRODUCTIVE CYCLES OF THE CHITONS, KATHERINA TUNICATA AND MOPALIA HINDSII

1. The reproductive cycles of two species of chitons, Katherina tunicata and Mopalia hindsii, collected in Monterey Bay are recorded, the first for three years and the second for two.2. Katherina breeds in the summer, Mopalia in the fall and winter.3. In each case the gonad index (ratio of gonad volume to body weight times 100) rises gradually and falls rather precipitously as spawning occurs. Differences in onset of breeding occurred during the years for which records are available, suggesting timing of events by local conditions.4. Blood protein, non-protein nitrogen, and reducing sugar vary during the year but it is not clear whether these variations are significantly correlated with reproductive condition.

On growth, feeding and reproduction in the chitonMopalia muscosa of Santa Monica Bay

KurzfassungAn Hand von Untersuchungen in der freien Natur und im Laboratorium werden neue Informationen vorgelegt über wichtige ökologische Parameter vonM. muscosa. Bei dieser Art kommt das Schalenwachstum während des Winters fast oder gänzlich zum Erliegen. Die Art ist herbivor und lebt vor allem von Rot- und Grünalgen. Beim Fortpflanzungsgeschehen können zwei Laichperioden unterschieden werden, von denen eine vor allem in den Winter fällt, die andere in den Vorfrühling.Summary1. InM. muscosa shell growth slows or stops during the winter months.2.M. muscosa in Santa Monica Bay are herbivorous and eat red and green algae as their main foods.3.M. muscosa exhibit two distinct spawning periods which occur mainly during winter and early spring.

Die Bedeutung abiotischer Faktoren für die Gonadenentwicklung und Fortpflanzung mariner Evertebraten

This review concerns itself with two aspects of reproductive biology: commencement of gametogenesis and spawning. The activation of gametogenesis followed by gonadal growth, with a subsequent release of gametes. The gamete formation-spawning cycle varies in duration from weekly to yearly periods depending upon the species and geographical origin. The importance of exogenous factors is discussed. Among those exogenous factors which can be demonstrated to affect the gamete formation-spawning cycle are food, salinity, light and temperature. Gonad growth constitutes a more significant fraction of the entire reproductive cycle than does spawning and gametogenesis. The time during which gametes are released occupies a small fraction of the entire reproductive cycle. Since spawning is such a dramatic act, it has been described in detail for many species. Numerous investigators have shown interest in the factors and relationships which work to insure synchronization of spawning. These studies are fully discussed. Some considerations of larval ecology in relation to parental reproductive patterns are given. Finally, the possible mechanism involved in coordination of reproduction is presented.

A histological study of the food canal ofStrongylocentrotus franciscanus

KurzfassungDer Nahrungskanal des SeeigelsS. franciscanus besteht aus vier verschiedenen Abschnitten: Pharynx, Oesophagus, Darm und Rectum. Die Wandung des Nahrungskanals setzt sich zusammen aus einem äußeren Epithel, zirkulären und longitudinalen Muskelschichten, einer Bindegewebsschicht und einem inneren Epithel. In den Wandungen von Pharynx und Oesophagus gibt es zwei Arten von Sekretionszellen; eine liefert mucoide, die andere acide Sekretionsprodukte. Der Magen (erste Intestinalschlinge) ist mit einem inneren Epithel ausgekleidet, welches gelbliche Körner enthält, die extrazelluläre Enzyme produzieren. Im inneren Epithel von Darm (zweite Schlinge) und Rectum konnten keine Sekretionsgranula nachgewiesen werden. Lipoide und Glykogen scheinen in der hinteren Magenhälfte vorzukommen und in der vorderen Hälfte des Darmes. Die Aktivität der alkalinen Phosphatase ist beschränkt auf die freie Begrenzung des inneren Epithels von Magen, Darm und Rectum.Summary1. The wall of the food canal is composed of an outer epithelium, layers of circular and longitudinal muscles, a layer of connective tissue of varying thickness, and an inner epithelium generally composed of very tall, slender cells.2. Two kinds of secretory cells are recognized in the pharyngeal and esophageal wall; one produces a mucoid secretion and the other an acid secretion. Numerous echinochrome containing amoebocytes and agranulocytes are distributed in the connective tissue layer and the basal region of the pharyngeal inner epithelium.3. The stomach is lined with an inner epithelium containing yellowish granules, which are discharged from its surface to provide extracellular enzymes. Large eosinophilic granulocytes, which are assumed to participate in digestion by ingesting particles and absorbing dissolved nutrient substances, are sometimes found to be imbedded within the stomach inner epithelium. The intestine and rectum, however, have never been found to contain any secretory granules nor any amoebocytes in the inner epithelium. Echinochrome-containing amoebocytes, however, are found in all tissues of the food canal.4. Lipids and glycogen appear to be deposited in the hinder half of the stomach and fore half of the intestine. Starvation for five weeks or more results in a significant decrease of these reserves.5. Alkaline phosphatase activity is restricted to the free border of the inner epithelium of the stomach, intestine, and rectum.6. It is concluded that the stomach functions in the digestion of foods, in absorption of the products of digestion, and that the intestine and rectum function as absorptive organs and a conductive tube for the elimination of undigested food materials.