Energy budget for the larval development ofElminius modestus (Crustacea: Cirripedia)

Biomass (CHN), respiration rate and food uptake were estimated for the larval development ofElminius modestus at three temperatures (12, 18, 24°C). Mean values of dry weight, elemental composition and energy equivalents increased exponentially with the development from nauplius II to VI. Dry weight, elemental composition and energy content exhibited the highest values at 18°C. Respiration rates increased with the larval stages expressed by a power function, but increased logarithmically with the dry weight of the larvae. The cypris larvae showed a reduced respiration rate compared with nauplius VI. The ingestion rate was measured at a concentration of 100 cells ofSkeletonema costatum μl⁻¹. At 12 and 18°C ingestion rates increased exponentially and at 24°C by a logarithmic function. The fittings were used to estimate the energy budget ofE. modestus during larval development. The energy content of the larvae increased during the development from nauplius II to VI by a factor of 21 at 12°C, 25 at 24°C and 31 at 18°C. The estimated energy content of the freshly metamorphosed barnacle is 100 mJ (12°C), 130 mJ (24°C) and 150 mJ (18°C). The assimilation- (A/I) and gross growth efficiencies (K₁) increased strongly during the development from nauplius II to VI (A/I: 6–14% in nauplius II to 50–90% in nauplius VI; K₁: 4% in nauplius II to 75% in nauplius VI). The net growth efficiency (K₂) showed a relatively constant level ranging between 57 and 83%.     

Effects of temperature and salinity on the larvae of two species of rhizocephalan (Crustacea: Cirripedia)

Summary

Responses of larvae of two rhizocephalan species to changes in seawater temperature and salinity were studied under laboratory conditions. Peltogasterella gracilis parasitizes the hermit crab Pagurus pectinatus, which occurs at stable salinity and gradually changing temperature in summer. Sacculina polygenea is a parasite of the crab Hemigrapsus sanguineus, which lives in the intertidal zone in summer where salinity and temperature can fluctuate during the day. The development of both species is comprised of five naupliar stages and the cyprid stage, and it was considered successful if more than 50% of the nauplii attained the cyprid stage. P. gracilis nauplii successfully developed at 12–20°C and 30–34‰, but at 22°C successful development occurred in a narrower salinity range (32–34‰). All nauplii died both at 25°C and in 26‰. S. polygenea nauplii successfully reached the cyprid stage at higher temperatures (18–25°C) and a wider salinity range (18–34‰) than P. gracilis nauplii, but at 12°C and 16‰ larval development of S. polygenea was suppressed. Under favorable conditions, naupliar development lasted 3.5 days in P. gracilis and 2–3 days in S. polygenea. The cyprids of both rhizocephalan species demonstrated a greater resistance to temperature and salinity changes than nauplii. However, P. gracilis cyprids were active in a narrower salinity range (16–34‰), as compared to S. polygenea cyprids (8–34‰). Under favorable conditions the cyprids of both species survived for 6 to 10 days.     

The neozoanElminius modestus Darwin (Crustacea, Cirripedia): Possible explanations for its successful invasion in European water

Comparison of data from the literature has provided evidence that eurythermal and euryhaline adaptation of larvae and adults in combination with a long seasonal breeding period, high fecundity and short generation time have givenElminius modestus an, advantage over indigenous cirripede species, allowing a rapid spread throughout European waters.     

Influence of temperature on larval survival, development, and respiration inChasmagnathus granulata (Crustacea, Decapoda)

Larvae of an estuarine grapsid crabChasmagnathus granulata Dana 1851, from temperate and subtropical regions of South America, were reared in seawater (32/%.) at five different constant temperatures (12, 15, 18, 21, 24 °C). Complete larval development from hatching (Zoea I) to metamorphosis (Crab I) occurred in a range from 15 to 24 °C. Highest survival (60% to the first juvenile stage) was observed at 18 °C, while all larvae reared at 12 °C died before metamorphosis. The duration of development (D) decreased with increasing temperature (T). This relationship is described for all larval stages as a power function (linear regressions after logarithmic transformation of bothD andT). The temperature-dependence of the instantaneous developmental rate (D ⁻¹) is compared among larval stages and temperatures using the Q₁₀ coefficient (van't Hoff's equation). Through all four zoeal stages, this index tends to increase during development and to decrease with increasingT (comparing ranges 12–18, 15–21, 18–24 °C). In the Megalopa, low Q₁₀ values were found in the range from 15 to 24 °C. In another series of experiments, larvae were reared at constant 18 °C, and their dry weight (W) and respiratory response to changes inT were measured in all successive stages during the intermoult period (stage C) of the moulting cycle. Both individual and weight-specific respiration (R, QO ₂) increased exponentially with increasingT. At each temperature,R increased significantly during growth and development through successive larval stages. No significantly differentQO ₂ values were found in the first three zoeal stages, while a significant decrease with increasingW occurred in the Zoea IV and Megalopa. As in the temperature-dependence ofD, the respiratory response to changes in temperature (Q₁₀) depends on both the temperature range and the developmental stage, however, with different patterns. In the zoeal stages, the respiratory Q₁₀ was minimum (1.7–2.2) at low temperatures (12–18 °C), but maximum (2.2–3.0) at 18–24 °C. The Megalopa, in contrast, showed a stronger metabolic response in the lower than in the upper temperature range (Q₁₀=2.8 and 1.7, respectively). We interpret this pattern as an adaptation to a sequence of temperature conditions that should typically be encountered byC. granulata larvae during their ontogenetic migrations: hatching in and subsequent export from shallow estuarine lagoons, zoeal development in coastal marine waters, which are on average cooler, return in the Megalopa stage to warm lagoons. We thus propose that high metabolic sensitivity to changes in temperature may serve as a signal stimulating larval migration, so that the zoeae should tend to leave warm estuaries and lagoons, whereas the Megalopa should avoid remaining in the cooler marine waters and initiate its migration to wards shallow coastal lagoons.     

Effects of temperature and salinity on embryonic development of turbot (Scophthalmus maximus L.) from the North Sea, and comparisons with Baltic populations

Optimum temperature and salinity conditions for viable hatch were studied for turbot (Scophthalmus maximus L.) from the North Sea. Temperatures ranging from 6 to 22°C and salinities from 5 to 35‰ were used. Optimum conditions were observed to be between 12 and 18°C at salinities between 20 and 35‰. This contrasted with corresponding data for turbot from the southern Baltic proper, according to which survival sharply decreased in temperatures below 14°C and was high in salinities of 10 to 15‰. Thus, it is concluded that Baltic and Atlantic turbot should be considered as different races.     

Larval development of the rhizocephalanSacculina polygenea (Crustacea: Cirripedia)

Larval development of the rhizocephalanSacculina polygenea (Crustacea: Cirripedia: Rhizocephala) parasitizing the coastal crabHemigrapsus sanguineus was studied in Vostok Bay, the Sea of Japan. At 22–23°C, the entire cycle of larval development takes 2.5 days and includes five naupliar stages and one cypris stage. Like other rhizocephalans, the larvae ofS. polygenea are lecithotrophic and only grow slightly in size in the course of development, and like all sacculinids, they have no flotation collar. The naupliar stages IV and V have a tubercle between the furcal rami; this tubercle is absent in the larvae of the genusPeltogasterella, but it has been described inS. carcini. The first seta of the antennule only disappears completely at the fourth stage, although it is markedly reduced at the third stage. No morphological differences, except differences in size, are found between male and female nauplii.     

The epizoic diatom community on four bryozoan species from Helgoland (German Bight, North Sea)

The composition of the diatom community on the bryozoans Electra pilosa, Membranipora membranacea, Flustra foliacea, and Alcyonidium gelatinosum from the German Bight was studied by light and scanning electron microscopy. In total, members of 26 diatom genera were found, with Cocconeis, Tabularia, Licmophora, Amphora, and Navicula being the most abundant. The amount and the composition of the diatom covering seem to be typical for single bryozoan species. Electra pilosa and Membranipora membranacea showed a rather dense covering with 71–547 cells/mm² and 77–110 cells/mm², respectively. The most prominent genus on Electra pilosa was Cocconeis, reaching up to 58% of all diatoms in one sample, followed by Navicula, Tabularia and Amphora. The most abundant genera on Membranipora membranacea were Tabularia and Licmophora, making up almost 70% of all diatoms in one sample, followed by Navicula, Cocconeis and Amphora. The diatom composition was very stable on all Electra samples, but varied on Membranipora samples. With <1–27 cells/mm², diatoms were much less abundant on Alcyonidium gelatinosum. Members of the genera Tabularia and Navicula were the most frequently found benthic diatoms, whereas the planktonic forms Coscinodiscus, Cyclotella, and Thalassiosira made up 35% of the diatoms. On Flustra foliacea, diatoms were virtually absent, with fewer than 5 cells/mm². The low diatom numbers are probably due to toxic metabolites produced by the host. The same may be true for Alcyonidium gelatinosum, but here they might also be a consequence of the surface properties of the bryozoan. Electronic Publication     

A revised checklist of planktonic diatoms and dinoflagellates from Helgoland (North Sea,German Bight)

A checklist based on net samples taken twice weekly from 2001 until May 2003 is presented. Identification is based on observations under direct light microscopy and after taking some organisms in culture. The checklist includes 227 taxa observed at the Helgoland Reede sampling station. One hundred and thirty-two species of diatoms from 53 genera and 95 species of dinoflagellates from 35 genera have been recorded from net samples and cultures. Thirty-five diatom and 28 dinoflagellate taxa were documented in the Helgoland phytoplankton for the first time. The list does not claim to be complete, but provides an updated list of the taxa found at Helgoland and, for convenience, also includes data published for different adjacent areas.Communicated by K. Wiltshire     

饵料、盐度和温度对刺巨藤壶幼虫生长发育的影响

刺巨藤壶(Megabalanus volcano)是沿海污损生物的优势种,也是沿岸居民常食用的海鲜之一。为探究刺巨藤壶幼虫室内培养的适宜条件,采用生态学单因子梯度实验方法,研究饵料种类及密度、盐度(18、22、26、30、34、38和42)和温度(14℃、18℃、22℃、26℃、30℃和34℃)等生态因子对刺巨藤壶幼虫生长发育的影响,以Ⅵ期无节幼虫存活率、Ⅵ期无节幼虫发育时间、金星幼虫存活率、金星幼虫发育时间和金星幼虫体长等为观察指标。中肋骨条藻(Skeletonema costatum)和牟氏角毛藻(Chaetoceros muelleri)均设置5×10⁴个/mL、10×10⁴个/mL、20×10⁴个/mL、40×10⁴个/mL和80×10⁴个/mL 5个密度梯度,亚心形扁藻(Platymonas subcordiformis)设置2.5×10⁴个/mL、5×10⁴个/mL、10×10⁴个/mL、15×10<...     

Gymnodinium blooms in the Helgoland bight (North Sea) during August, 1968

Summary 1. As in other parts of the North Sea, dinoflagellate red tides occurred in Helgoland waters in August, 1968. Measurements of plankton, and physical and chemical water properties at the permanent station Helgoland Roads were analyzed to describe the blooms. In addition, planktological and hydrographical investigations at three areas south, southwest and northwest of Helgoland on 27 and 28 August, as well as at two drifting stations off the mouths of the Elbe and Eider rivers on 6 and 8 August, were used for this work.2.Gymnodinium sp. was abundant at all these localities, forming blooms near Helgoland from 14 to 30 August, with a maximum of 3 to 3.25 × 10⁶ cells/l (and 18 to 19µg chlorophylla/l) on 28 and 30 August at Helgoland Roads. The primary production was as high as 0.98 mg C/l in 6 hours in a suspension of 3.7 × 10⁶ Gymnodinium/l, where diatoms had been removed. This means that one millionGymnodinium produced 0.265 mg C in 6 hours. At Helgoland Roads nitrate and nitrite were depleted at times, but not phosphate.3. About 3 × 10⁶ Gymnodinium sp./l were found in the upper 16.5 m of water investigated around Helgoland on 27 and 28 August (maximal 7.8 × 10⁶ cells/l at 3 m). There was a marked vertical stratification ofGymnodinium with a concentration towards the surface during the day. This was particularly the case in the turbid water off the Elbe estuary, where numbers up to 0.3 × 10⁶/l were counted.Gymnodinium sp. formed 96 to 99 % of the phytoplankton biomass during maximal development. The chlorophylla content of one millionGymnodinium was only 3.5µg. An extinktion of E=0.083/1 m was measured in a suspension of 10⁶ Gymnodinium/l in samples with minimal other plankton and detritus.4. The water masses containingGymnodinium blooms, which reached Helgoland after a change of wind direction, were characterized by lower salinity and higher temperature. This indicates that blooms developed in the coastally influenced water masses east of Helgoland. The red tides occurred during a period of minimal discharge of Elbe river water and of relatively high salinity of the coastal water in the Inner German Bight. They developed after a long period of calm winds. There were no records of reported fish or shellfish poisoning.

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Gymnodinium-Wucherungen in der Helgoländer Bucht (Nordsee) im August 1968

Kurzfassung Wie in anderen Teilen der Nordsee traten auch in der Helgoländer Bucht im August 1968 starke Wucherungen von Dinoflagellaten auf. Untersuchungen des Planktons und der Wassereigenschaften auf der Helgoland-Reede sowie auf weiteren Stationen in der Helgoländer Bucht wurden für die Erklärung dieser Erscheinung ausgewertet. In allen untersuchten Gebieten (Fig. 1) fand sichGymnodinium sp. als dominante Planktonform. Gymnodinien-Wucherungen traten auf der Helgoland-Reede in der Zeit vom 14.–30. August auf und erreichten Zellzahlen von über 3 × 10⁶/l am 28. und 30. August, bei nur 18–19µg Chlorophylla/l. Eine Million Gymnodinien produzierten 0,265 mg C in 6 Stunden im Inkubator. Etwa 3 × 10⁶ Gymnodinium sp. wurden in den obersten 16,5 m der Wassersäule in der Nähe Helgolands während des Blüte-Maximums gemessen (maximal 7,8 × 10⁶/l in 3 m). Die Gymnodinien waren tagsüber in den obersten Metern konzentriert. Eine solche Vertikalschichtung war besonders im Küstenwasser vor der Elbmündung ausgeprägt, wo bis zu 0,3 × 10⁶ Zellen/l gefunden wurden.Gymnodinium sp. bildete 96–99 % der Biomasse während der Blüte bei Helgoland. Es wurden ein Chlorophyll-a-Gehalt von nur 3,5µg für 10⁶ Zellen ermittelt und eine Extinktion von E=0,083/1 m für eine Suspension von 10⁶ Gymnodinien/l in Proben mit minimalem Gehalt an übrigem Plankton und Detritus gemessen. Der Nitrat- und Nitritgehalt im Wasser war zeitweise erschöpft, nicht aber das Phosphat. Wenn Wassermassen mitGymnodinium-Blüten nach Helgoland gedriftet wurden, fiel der Salzgehalt, und die Temperatur stieg an, was auf eine Entstehung der Wucherungen im brackwasser-beeinflußten Gebiet östlich Helgolands hindeutet. DieGymnodinium-Blüten entwickelten sich nach einer außergewöhnlich langen windarmen Periode und während eines minimalen Süßwasserzuflusses aus der Elbe. Vergiftungserscheinungen an Seetieren wurden bei Helgoland nicht festgestellt.

     

Effects of juvenile hormone analogues on larval metamorphosis in the barnacle Elminius modestus Darwin (Crustacea: Cirripedia)

Two analogues of insect juvenile hormones (JH) have been shown to interfere with the development of Elminius modestus Darwin larvae when dispersed as acetone solutions in sea water. Stage VI nauplii metamorphosed to morphologically abnormal larvae which were intermediate in size between the nauplius and cypris stages; although these larvae were cypris-like they apparently retained some nauplius characteristics. Cyprids either metamorphosed to non-attached adults or formed larvae which were larger or morphologically abnormal. There was evidence that the effects may be related to the physiological development of the larvae at time of exposure. These observations appear to be the first report of the induction of size and morphological abnormalities in a crustacean species by analogues of insect JH and resemble those arising from the hormonal imbalance which such compounds induce during the development of holometabolous insects.     

The impact of food type, temperature and starvation on larval development of Balanus amphitrite Darwin (Cirripedia: Thoracica)

The impact of diatom food species (Chaetoceros calcitrans and Skeletonema costatum), temperature and starvation on the larval development of Balanus amphitrite was evaluated. Starvation threshold levels for different ages of larvae (0- to 5-day-old) fed with C. calcitrans and S. costatum and then starved at 5, 15 and 25 °C temperature were estimated as ultimate recovery hour (URH; denoting the starvation point in hours at the end of which larvae can recover and continue development). Effect of temperature on starvation threshold varied significantly with larval age and food species. The URH declined with larval age at 5 °C, but not at 15 and 25 °C. The URH and grazing rates were high for early instars fed on C. calcitrans, and for advanced instars fed on S. costatum. Carbon gain through feeding was maximum for 2-day-old larvae when fed with C. calcitrans and decreased with larval age. However, when fed with S. costatum carbon gain increased with larval age. This confirms that with development the utility of food types changes. The differences in the carbon gain can be attributed to differences in grazing rate due to variations in the size of the diatom cells, larval intersetular distance, diatom sinking rate and the photo-taxic behavior of larvae. Molting was observed at times when larvae were undergoing starvation and this could be viewed as stress-induced molting, and it differed with the larval age and food organisms.     

The influence of salinity on fertilization and larval development of Nereis virens (Polychaeta, Nereidae) from the White Sea

Effect of salinity on fertilization and early development of the polychaeta Nereis virens (Sars) from the White Sea was examined in laboratory experiments. The comparison of salinity resistance of different developmental stages of N. virens showed gradual increase of euryhalinity during ontogenesis—from fertilized eggs to juveniles.Successful fertilization and effective development (≥70-75%) was possible in narrow salinity range 22-34‰. The salinity range of successful development for trochophore and nectochaete larvae reached 14-45‰. This increase of the limits of salinity tolerance in trochophore and nectochaete larvae probably was due to the formation of protonephridium system.Rate of metamorphosis of N. virens was tested under temperature 5, 10, 17 and 23 °C and salinity 22-14‰. The highest rate of metamorphosis was marked at the temperature of 23 °C in salinities higher than 14‰.Our data confirms that N. virens originates from warm seas with oceanic salinity.     

Community composition of the rocky intertidal at Helgoland (German Bight,North Sea)

At the rocky island of Helgoland (North Sea), the distribution and abundances of intertidal communities were assessed and the effects of wave exposure and tidal height on the spatial distribution patterns of the communities were evaluated. Macroalgae and invertebrates were sampled quantitatively along line transects in three intertidal locations, a semi-exposed, an exposed and a sheltered one. The semi-exposed location was characterised by (1) Ulva spp. at the high intertidal (Ulva-community), (2) mussels and periwinkles at the mid intertidal (Mytilus-community) and (3) Corallina officinalis and mainly the large brown alga Fucus serratus at the low intertidal (Fucus-community). The exposed location encompassed the mid and low intertidal; at both zones the Fucus-community occurred. The sheltered location was characterised by (1) barnacles (Balanus-community) and (2) bryozoans, hydrozoans and mainly the large brown alga Ascophyllum nodosum (Ascophyllum-community). At the semi-exposed, but not at the exposed location the communities changed with the intertidal position. A relationship between wave exposure and the occurrence of specific communities was shown for the sheltered location; in contrast, communities of the semi-exposed and the exposed location appear to be little influenced by wave exposure directly. The community concept and the potential causes of distribution patterns of the defined communities are discussed and suggestions for a future monitoring are given. Variations in the communities at different spatial scales speak in favour of a multiple scale sampling design to monitor changes in the intertidal communities at Helgoland. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Effects of temperature and salinity on the growth of Alexandrium (Dinophyceae) isolates from the Salish Sea

Toxin‐producing blooms of dinoflagellates in the genus Alexandrium have plagued the inhabitants of the Salish Sea for centuries. Yet the environmental conditions that promote accelerated growth of this organism, a producer of paralytic shellfish toxins, is lacking. This study quantitatively determined the growth response of two Alexandrium isolates to a range of temperatures and salinities, factors that will strongly respond to future climate change scenarios. An empirical equation, derived from observed growth rates describing the temperature and salinity dependence of growth, was used to hindcast bloom risk. Hindcasting was achieved by comparing predicted growth rates, calculated from in situ temperature and salinity data from Quartermaster Harbor, with corresponding Alexandrium cell counts and shellfish toxin data. The greatest bloom risk, defined at μ >0.25 d^?1, generally occurred from April through November annually; however, growth rates rarely fell below 0.10 d^?1. Except for a few occasions, Alexandrium cells were only observed during the periods of highest bloom risk and paralytic shellfish toxins above the regulatory limit always fell within the periods of predicted bloom occurrence. While acknowledging that Alexandrium growth rates are affected by other abiotic and biotic factors, such as grazing pressure and nutrient availability, the use of this empirical growth function to predict higher risk time frames for blooms and toxic shellfish within the Salish Sea provides the groundwork for a more comprehensive biological model of Alexandrium bloom dynamics in the region and will enhance our ability to forecast blooms in the Salish Sea under future climate change scenarios.     

Effects of salinity and temperature on oxygen consumption in a freshwater population of Palaemonetes antennarius (Crustacea,decapoda)

• 1.1. After step-like increases in salinity the shrimps exhibit the smallest increase in oxygen consumption in the lower salinity range. At higher salinities the shrimps show longer recovery times and greater increases in the metabolic rate after salinity shock.
• 2.2. In steady-state experiments, the shrimps display the lowest oxygen consumption rates near the isosmotic point. The lowest metabolic rates occur at salinities of 3‰ and 10‰ At salinities of 20‰ and above the rate of metabolism increases by 20–30%.
• 3.3. The calculated osmoregulatory work for animals in fresh water amounts to only 2.7% of routine metabolism and drops to 1.1% for shrimps in 3‰ and 0.7% in 5‰ salinity.
• 4.4. Locomotory activity in the form of position change was not responsible for the increased oxygen consumption of the animals after salinity shocks. A “tentative swimming activity” by fast and frequent beating of the pleopods without position change may be an important factor in the increase of metabolic rates.
• 5.5. In its temperature response, the brackish water population has a higher metabolic rate than the freshwater one. Between 5 and 35°C Q ₁₀-values range from 4.01 to 1.37.

     

Taphonomy and systematics of a new Late Cretaceous verrucid barnacle (Cirripedia,Thoracica) from Canterbury,New Zealand

Abstract: Cirripede remains (Thoracica, Verrucomorpha), found associated with the mosasaur Prognathodon waiparaensis  Welles and Gregg, 1971 in glauconitic sands of the Late Cretaceous Conway Formation exposed along the Waipara River bank (mid‐Canterbury, New Zealand), are identified as a new species, Verruca sauria sp. nov. On the basis of taphonomy, it is deduced that these verrucids grew on a postmortem accumulation of mosasaur bones under very quiescent conditions. The current amphitropical distribution of the earliest known verrucids, i.e. V. sauria sp. nov., V. prisca  Bosquet, 1854 , V. pusilla  Bosquet, 1857 and V. tasmanica  Buckeridge, 1983 , is rationalized in the light of Tethyan palaeogeography.     

Littoral barnacles of The Snares islands,southern New Zealand (Cirripedia: Thoracica)

Abstract

Ibla idiotica, Lepas australis, Calantica villosa, Chamaesipho columna, Tetraclitella purpurascens, Notobalanus vestitus, and Notomegabalanus campbelli are reported for the first time from The Snares. The occurrence of Calantica spinosa and Epopella plicata is confirmed. Habitat information and recorded distribution in New Zealand are given for each species. The Snares barnacle fauna is restricted both in diversity and in numbers of individuals. This may be due to high wave energies, strong winds which aid desiccation, and counter-flow of currents, which might disrupt larval dispersal from the north and north-west.     

New record of Lithodidae (Crustacea Decapoda, Anomura) from the Antarctic (Bellingshausen Sea)

During the Bentart-2003 Cruise, carried out during austral summer 2003 in the Bellingshausen Sea, three species of Lithodidae, Paralomis birsteini, Lithodes murrayi and Neolithodes capensis, were caught from 218 m to 1947 m. With these captures the presence of L. murrayi in Peter I Island is confirmed, the distribution area of N. capensis is greatly increased and the captures of N. capensis and P. birsteini represent the first lithodid record known from the Antarctic continental slope. Also, these records show large and discontinuous distributions, which illustrate that many distribution patterns of Antarctic species are more an artefact of limited studies than representing actual distribution.     

Biodiversity and Biogeography of Chthamalid Barnacles from the North-Eastern Pacific (Crustacea Cirripedia)

The biogeography and ecology of the species of Chthamalus present on the west coast of America are described, using data from 51 localities from Alaska to Panama, together with their zonation on the shore with respect to that of other barnacles. The species present were C. dalli, Pilsbry 1916, C. fissus, Darwin, 1854, C. anisopoma Pilsbry 1916 and four species in the C. panamensis complex. The latter are C. panamensis Pilsbry, 1916, C. hedgecocki, Pitombo & Burton, 2007, C. alani nom. nov. (formerly C. southwardorum Pitombo & Burton, 2007) and C. newmani sp. nov.). These four species were initially separated by enzyme electrophoresis. They could only be partially separated by DNA bar coding but may be separated using morphological characters.