Growth Of Barnacles Research Articles

Barnacle fouling on relict foraminiferal specimens from the western continental margin of India: an indicator of paleosea-level

In order to study paleosea-level along the west coast of India, surficial sediment samples within the depth zone of 15–1750 m were analysed. The results indicate the presence of abundant relict foraminiferal specimens, encrusted with sessile cirripedes Tetraclita squamosa in a depth zone between 60 and 90 m. The relict foraminiferal assemblage is dominated by reefal species, Amphistegina and Nummulites. The associated sediments are rich in oolites and show an age of approximately 9000–11,000 year B.P. ( 14C dating). The relict fauna and oolites both indicate a high energy, carbonate rich shallow-water depositional environment. The cirripedes show a high energy intertidal depth of deposition. Tetraclita squamosa have been reported by earlier workers from modern high salinity environments. However, this species is absent in the recent environment within the study area. Furthermore, these forms were found associated only with relict specimens of foraminifera. This shows that they lived in this area and encrusted on foraminiferal tests when the sea level was low, (at about 10,000 B.P.) and could not keep pace with the rise in sealevel (and also with a change in the salinity pattern) and disappeared in the course of time from the study area. Therefore, it is proposed that intertidal barnacle growth on foraminifera, can be considered as an additional tool, to monitor paleo-sealevel changes.

Observation on the Settlement and Growth of Barnacles in Tokyo Bay, Japan.

Observation on the Settlement and Growth of Barnacles in Tokyo Bay, Japan.

Settlement as a major determinant of intertidal oyster and barnacle distributions along a horizontal gradient

In Galveston Bay, Texas, pier pilings within 10 m of the shore are dominated by the American oyster Crassostrea virginica (Gmelin) while the ivory barnacle Balanus eburneus (Gould) predominates on pilings beyond 10 m. This pattern of horizontal zonation reflects differential settlement: barnacles and oysters settle in areas of high and low water motion, respectively. High water motion promotes barnacle growth, but has no effect on oyster growth. The higher settlement of barnacles onto substrata in higher water motion appears to be a combination of arrival rates to these sites and a preference for these areas. Adult-larval interactions further enhance the degree of differential settlement. Differential settlement is a major determinant of the horizontal zonation observed between these two species and may serve as a mechanism for avoiding potentially detrimental post-settlement interactions.

Absence of gregarious settling Behaviour by female cypris larvae of British parasitic rhizocephalan barnacles

Barnacle cypris larvae, the specialized settlement stage of the life-cycle, are classical examples of larvae showing gregarious settlement. Gregarious settlement is shown when the larva is induced to settle by established individuals of its own or of a closely related species, reflecting the ability of the larva to recognize its own type, usually by chemo-tactile detection of a particular settlement inducing factor (see Crisp (1974) for review). Sessile barnacles such as species of Balanus or Chthamalus are typically hermaphrodite and gregarious settlement is of selective advantage in promoting the possibility of cross-fertilization, in addition to allowing a settling larva to identify a habitat providing all the necessary conditions for barnacle growth and development.

Factors affecting deposition of the shell in Balanus balanoides (L.)

The growth of littoral and sublittoral barnacles has been studied in some detail using linear, surface or volumetric measurements (see Barnes & Barnes, 1959). The growth curve in terms of linear dimension generally included an extended straight section which implies, assuming a constant shape, that the volume is increasing with time in proportion to the area (Crisp, 1960). Hence a plot of basal diameter against time is the simplest characteristic of the growth during most of the life of an isolated specimen. In most studies the shells are measured at daily, weekly or monthly intervals and the effect of different factors on growth evaluated. Thus, it has been claimed experimentally that many factors influence directly the growth of barnacles. These factors and their effects are outlined in Table 1.

Thermal Additions and Epifaunal Organisms at Chalk Point, Maryland

Two sets of test panels, one in the intake and the other in the effluent canal of a steam-generating station, were submerged at montly intervals in 1967. The panels were analyzed for epifaunal species composition, abundance, seasonal attachment, and total biomass production. The average surface-water temperature rose 6.3 C above ambient on the effluent side, and the biomass production of the epifaunal organisms found there increased nearly three times that of the intake. An earlier and larger set of some attached organisms occurred in the effluent, but there was little change in species composition between the intake and effluent canals. During the summer when high surface-water temperatures prevailed, there seemed to be a reduced number and/or disappearance of flatworms and colonial hydroids, along with increased barnacle growth. *** DIRECT SUPPORT *** A00BY035 00006

Rapid Growth in Stalked Barnacles

AN example of the rapid growth in pedunculate barnacles has been seen in a mixed population of Lepas anatifera and Conchoderma virgata taken from the newly painted surface of a buoy recovered off the east coast of Australia (31° 14′ S., 153° 12′ E.) on December 2, 1960. The buoy was laid (30° 36′ S., 153° 28′ E.) 17 days previously and on recovery was coated with large barnacles, some releasing larvae. The maximum dimension of the capi-tulum was measured (Fig. 1); in preserved material this is half the total length.

An AIML Cooperative study of primary production in tropical and subtropical waters : Lewis, John B., Ivan Goodbody and John R. Beers, 1962. (Abstract). Ass. Island. Mar. Labs., 4th Meet., Curaçao, 18–20 Nov., 1962: 23

In Galveston Bay, Texas, pier pilings within 10 m of the shore are dominated by the American oyster Crassostrea virginica (Gmelin) while the ivory barnacle Balanus eburneus (Gould) predominates on pilings beyond 10 m. This pattern of horizontal zonation reflects differential settlement: barnacles and oysters settle in areas of high and low water motion, respectively. High water motion promotes barnacle growth, but has no effect on oyster growth. The higher settlement of barnacles onto substrata in higher water motion appears to be a combination of arrival rates to these sites and a preference for these areas. Adult-larval interactions further enhance the degree of differential settlement. Differential settlement is a major determinant of the horizontal zonation observed between these two species and may serve as a mechanism for avoiding potentially detrimental post-settlement interactions.

Effect of Carbonic Anhydrase Inhibitors on Shell Development and Growth of Balanus improvisus Darwin

CARBONIC CARBONIC anhydrase, associated with respiration in some invertebrate and vertebrate animals, has been found in the shell-forming tissues of many mollusks (Freeman and Wilbur, 1948). More recently (Wilbur and Jodrey, 1955) it has been demonstrated that the enzyme is directly associated with shell deposition and that inhibition of carbonic anhydrase reduces the rate of calcium carbonate deposition both in whole oysters and in mantle-shell preparations. The calcareous shell plates of the acorn barnacles are similar to mollusk shells, in that much of the crystalline material deposited in the organic matrix is calcium carbonate. The enzyme systems associated with shell development and growth in barnacles are not known, and, although carbonic anhydrase has been reported from a wide variety of invertebrates (Brinkman, 1933, Ferguson, Lewis, and Smith, 1937), acorn barnacles have not been among the animals included in the studies. Darwin (1854) postulated that the calcareous plates of the Balanidae are formed by the apposition of the mantle against the older portions of the shell, but few additional studies have been made on shell development. The present study has had two major objectives: (1) to determine whether or not carbonic anhydrase is present in the shell-forming mantle and internal body tissues of Balanus improvisus Darwin and (2) to study the effects of carbonic anhydrase inhibitors on shell development, shell growth, and molting.

MOULTING AND GROWTH IN BALANUS IMPROVISUS

The Cirripedia differ from other arthropods in that the body is enclosed by calcareous plates which are not shed with the chitinous layers of the animal body and the inner lining of the mantle. As early as 1854 Darwin reported that members of the families Balanidae and Chthamalidae underwent periods of exuviation. He reports that Mr. W. Thompson of Belfast kept twenty specimens of Balanus balanoides alive, presumabLy in the laboratory, and on the twelfth day all had moulted once and one individual twice. The frequency of moulting over an extended period of time has not been determined accurately for any sessile barnacle, presumably because of the difficulties involved in maintaining them in the laboratory. Thomas (1944) reports that moults of a selected group of Balanus perforatus of uniform size but unknown age occurred about every fifth day but makes no reference to the period over which these observations were made. Other than these observations there has been no statement, to our knowledge, concerning the relationship between growth of shell plates and ecdyses nor is the frequency of moulting and the intermoult period, from the time of settling, known for any length of time in any barnacle. The purpose of this investigation was to determine, therefore, a medium which would support growth of barnacles in the laboratory, to ascertain the time of moulting, period of intermoult, and the relationship of shell growth to the moulting cycle. Balanus improvisus Darwin, a barnacle which settles at Beaufort, N. C. during the winter and spring months, was selected for this study.

INSECTICIDES FOR PREVENTING BARNACLE SETTLEMENT

During the summer of 1950 experiments were made to test the use of insecticides for preventing the fouling of oyster spat collectors by the barnacle Elminius modestus.The insecticides used were DDT, BHC (benzene hexachloride‐γ‐isomer) and dieldrin (hexachloro‐epoxy‐octahydro‐dimethano‐naphthalene), made up as 5% solutions and tested on egg‐box collectors and quarry tiles. The tiles were used for frequent observations on settlement.When the solutions were sprayed on to the surfaces, in sufficient quantity to give a covering of 200 mg./ft.2 of active insecticide, none of them interfered with either barnacle or oyster settlement.When the test surfaces were dipped in the solutions, DDT and BHC prevented barnacle settlement almost completely, while dieldrin reduced it by approximately 50%. Settlement of Ostrea edulis was also reduced on the treated surfaces.Urea‐formaldehyde resins made up as varnishes, to which DDT or BHC had been added, were also tested. A varnish incorporating 20% by weight of DDT provided an effective anti‐fouling compound which lasted at least 3 months and completely prevented barnacle settlement.The possibility of insecticides dissolving into the water and inhibiting barnacle growth on adjacent surfaces is discussed.

The Brown Alga Durvillea antarctica in Australian Waters

THE massive brown alga Durvillea antarctica (Cham.) Hariot has recently been found washed up in three different places on the Australian coast. Miss Alison Baird, of the University of Western Australia, has informed us that a piece, 8–9 cm. long, of an almost cylindrical thong-like segment was found in drift at Nornalup on the south coast, about seventy miles west of Albany, in December 1947. A similar piece was included in a display of New Zealand seaweeds at the Hobart meeting of the Australian and New Zealand Association for the Advancement of Science in January 1949; on that occasion one of us (L. B. M.), in company with Miss Baird, collected from drift at Taroona, on the west side of the Derwent Estuary below Hobart, a partly decomposed fragment of about the same dimensions. In February 1950, the other (A. B. C.) found a plant 2 m. long and only lacking the holdfast at Port Arthur on the east coast of Tasmania; most of it was in good condition, though it bore a heavy growth of barnacles (Lepas sp.), which may indicate that it had been floating for some time. A portion of it has been compared with New Zealand D. antarctica, which it matches well.

The Development, General Morphology and Subsequent Elimination of Barnacle Populations, Balanus crenatus and B. Balanoides, After a Heavy Initial Settlement

Reference has already been made to the abundance of the larvae of Balanus balanoides (L.) and B. crenatus Brug. in the plankton, and the subsequent unusually heavy settlement on the shore and on submerged panels in the Firth of Clyde during the spring of I1949 (Barnes, 1950; Barnes & Powell, 1950). Control panels of Bakelite were exposed throughout this heavy barnacle settlement, and on such submerged panels both B. crenatus and B. balanoides settled together very abundantly, giving rise to some interesting morphological features of barnacle growth. Coincident with these observations, as part of an extensive study of colonization on cleared areas of the shore, similar morphological features were observed in B. balanoides.

Influence of X-Rays on Limb Regeneration in Urodele Amphibians

Influence of X-Rays on Limb Regeneration in Urodele Amphibians

Observations on the Abnormal Development and Growth of Barnacles as Related to Surface Toxicity

Observations on the Abnormal Development and Growth of Barnacles as Related to Surface Toxicity

EFFECT OF WATER CURRENTS UPON THE ATTACHMENT AND GROWTH OF BARNACLES

1. The work of previous authors, dealing with the effect of water currents upon barnacle attachment, growth and distribution is briefly reviewed.2. Experiments were conducted to determine the effects of water currents upon the attachment and growth of barnacles, and particularly of Balanus amphitrite. Submerged rotating discs and glass tubes of graded cross-sectional diameter were employed to provide variations in current velocity.3. The velocity of water current limiting attachment appears to lie between 0.5 and 0.9 knot for Balanus amphitrite, between 0.4 and 0.7 knot for B. eburneus, and above 1.1 knots for B. improvisus.4. Following attachment the growth rate of barnacles was found to be increased by water currents of velocity less than 1.5 knots and to be decreased by currents with velocities in excess of this. The adverse effects of water currents were found to decrease with increasing age of the barnacles subsequent to attachment. Six hours after attachment, growth rate was reduced to one-third of normal by a 1.5 knot current and completely stopped by a 3 knot current. Five days after attachment, growth was prevented by currents ranging between 3.3 and 8 knots. Loss of attachment appeared to some extent among all barnacles in which growth rate was reduced. This loss was greatest at velocities bringing about complete cessation of growth.5. It is suggested that loss of attachment is due to interference with the feeding process, followed by reduction of growth rate, death, and diminished adherence. Possibly due to an orientation to the current which facilitates feeding, barnacles attached for one day or less show less retardation of growth rate and loss of adherence than barnacles two days old.6. Since tidal currents are almost invariably intermittent it appears from the data presented that they are not sufficient to prevent the colonization of suitable surfaces by barnacles, except where the velocities are unusually high.It also follows from the numerical results obtained that on vessels making short stays in port and relatively long voyages, little permanent barnacle fouling will occur, since those organisms which attach will be killed and at least a portion of them dislodged. The evidence does not preclude, however, the continued growth of barnacles upon slow vessels making longer stays in port, and their geographical distribution by this means.

XIV. Notes on the Shoals at Caticol Point and Kirn Point, Arran

Between Loch Ranza and Caticol, and just south of Caticol Point, there is a considerable shoal formed of blocks of rock and shingle which is only exposed at low water, and is then seen to be covered by a strong growth of long seaweeds. It extends southwards for about 300 yards, and is separated from the gravelly sea-beach by a shallow and sandy channel. It has often been assumed that the boulders forming this shoal are of granite and slate, which have been transported down Caticol Glen or Loch Ranza Glen, and the grey coating on many of them, caused by the growth of barnacles, has doubtless led to this supposition. A casual look at the stone walls in front of Caticol Farm, near the shoal from which I ascertained the materials had been obtained, showed that they contained many blocks of red limestone, some much perforated by borings of the Pholas . I was therefore induced to make a careful examination of the shoal itself, and on doing so I found that, while there are a few granite and slate blocks, and these amongst the largest, the great mass of the collection consists of fragments of red limestone, red and grey sandstone, quartzite, dolerite, and conglomerate, of all sizes, large and small. Nearly all of them are angular, and they lie mingled together in the most indiscriminate way. Some of the specimens of these rocks which are now exhibited will give a good idea of their characteristics. The massive red This 250-word extract was created in the absence of an abstract