Spatial and temporal variation in the abundance and composition of ichthyoplankton in a large South Island,New Zealand river estuary

Larval and juvenile fish drifting on ebb tides were collected from early summer to mid autumn at various locations in the Taieri River and Waipori River estuary, South Island, New Zealand. A total of seven species of fish were recorded, however only three species were regularly collected. These were the larval common bully (Gobiomorphus cotidianus McDowall), larval inanga (Galaxias maculatus Jenyns), and postlarval cockabully (Tripterygion nigripenne Valenciennes). Common bully densities were highest in mid January, with the highest densities being recorded drifting out of Lake Waihola. Inanga densities were highest in March and April, with the highest densities being recorded in the channels draining wetland areas where extensive tidal inundation of riparian vegetation occurred. Cockabully were recorded from February to April, mostly at more downstream sites. Inland penetration by marine species was considerable, with two marine species, clingfish (Trachelochismus pinnulatus Forster) and smooth leatherjacket (Parika scaber Forster), being recorded c. 12 km upstream in late summer.     

Tethya (Porifera,Demosponglae) Species Coexisting in a Maldivian Coral Reef Lagoon: Taxonomical,Genetic and Ecological Data

Abstract. Tethya microstella, T. orphei, T. robusta, and T. seychellensis live in sympatry in a Maldivian coral reef lagoon (Gangehi Island, Ari Atoll). A morphological, morphometric, and electrophoretical study of these species show that their Maldivian populations are well separated morphologically and genetically. The genetic distances and the other data are more consistent with an immigration than with a local speciation hypothesis. Their coexistence may be explained by a differentiation in ecological requirements. The four species inhabit the shallow water biotope of the lagoon among the rubble of dead corals. Our data show that T. orphei and T. seychellensis occupy the upper rubble layer, T. microstella and T. robusta the lower one. This distinction agrees with the different morpho-functional features of the two pairs of species.     

Biology of evechinus chloroticus (echinoidea: Echinometridae) from different localities

The distribution, general habits, morphological variation, food, associates and predators ‘Of the common endemic New Zealand echiooid Evechinus chloroticus (Val.) are considered.

Evechinus chloroticus is chiefly a rocky bottom dweller but adults, juveniles and very small individuals often occupy different microhabitats. The urchin is typically found in shallow subtidal situations (<12m) although considerable intertidal populations occur in some areas, particularly towards the north. A superimposed dispersion pattern of population and intra‐population clumping is typical and densities often exceed 50 adults/m².

Spine length, thickness and sharpness and test thickness vary between populations but no significant variation in test shape (height/diameter) was observed. Variations in spination are probably related to wave exposure while test thickness is at least in part related to nutrition.

In the localities where macroscopic algae are diverse and abundant, Evechinus is almost exclusively algivorous, but it predominantly browses material from the substrate where algae are sparse.

The rhabdocoele, Syndesmis sp. (in the gut) and various tiliates (in the gut and gonad) were commonly found in Evechinus. The urchin provides shelter and food for the clingfish Dellichthys morelandi, and the isopod Exosphaeroma sp. is probably also a close associate.

Known predators include the cymaitiid gastropods Charonia capax and C. rubicunda, the seastar Coscinasterias calamaria, and the blue cod Parapercichthys colias and snapper Chrysophrys auratus.     

Monterey Bay cold-seep biota: Assemblages,abundance, and ultrastructure of living foraminifera

Although there is a growing body of evidence indicating benthic foraminifera inhabit hydrocarbon and cold seep environments, biochemical and ultrastructural data on seep foraminiferal communities are not available. Therefore, sediments collected from cold seeps in Monterey Bay, CA (900–1000 m), were examined for the presence of live benthic foraminifera. Results from three independent methods (ATP assay, ultrastructural analysis, rose Bengal staining) indicate that certain species inhabit the Clam Flat and Clam Field seeps. Abundances in our seep samples were lower than in comparable non-seep sites, although not atypical for these bathyal depths. Of 38 species represented at these two seep sites by cytoplasm-containing specimens, only Spiroplectammina biformis was restricted to the seep environment. However, because S. biformis is also known from non-seep sites in other areas, it should not be considered as endemic to seeps. Ultrastructural studies show abundant peroxisomes in seep specimens, which may allow inhabitation of such environments. One specimen of Uvigerina peregrina had prokaryotes nestled in test pores, suggesting that bacteria may play a role in the survival of foraminifera in this seep environment.     

The distribution of spiny lobsters in New Zealand waters (Crustacea: Decapoda: Palinuridae)

Two species of spiny lobsters (marine crayfish) inhabit New Zealand waters: Jasus edwardsii (Hutton, 1875), and J verreauxi (H. Milne Edwards, 1851). J edwardsii, the more common species, is present along most rocky coastlines in New Zealand, but is more abundant in the south‐west of the South Island and at the Chatham Islands. The species apparently reaches its northern limit of distribution at the Three Kings Islands (34°S) and its southern limit at the Auckland Islands (51°S).

J. verreauxi, the less common species, is almost solely restricted in New Zealand waters to the north‐east coast of the North Island. It is uncommon in the west and the south of the North Island, and is rare in the South Island. J. verreauxi apparently reaches its northern limit of distribution at the Kermadec Islands (31°S), and its southern limit near Bluff (47°S) in the South Island.     

New Zealand xenophyophores: Upper bathyal distribution,photographs of growth position,and a new species

Xenophyophores are a group of giant, but extremely fragile, rhizopod protozoans generally found at lower bathyal or abyssal depths. Recent dredge samples and photographs suggest that there is a largely endemic fauna of xenophyophores with anastomosing branches living at upper bathyal depths around New Zealand. Their distribution may be related to the layer of Antarctic Intermediate water that bathes the upper slope of the New Zealand Plateau.

Photographs of the seafloor at depths of 800–1300 m on the Lord Howe Rise show hemispherical masses, 5 cm across, of which the majority appear to be Syringammina tasmanensis Lewis, 1966 and at least one specimen may be Reticulammina lamellata Tendal, 1972. The photographs indicate that these species live on the seabed, not beneath it, that they are probably filter feeders and that they can reach a density of about one specimen per square metre.

A new species, Reticulammina maini, is described from the continental slope east of Auckland. A key to the New Zealand species of xenophyophore is presented.     

The impact of rising sea temperature on innate immune parameters in the tropical subtidal sea urchin Lytechinus variegatus and the intertidal sea urchin Echinometra lucunter

Ocean temperatures are rising throughout the world, making it necessary to evaluate the impact of these temperature changes on sea urchins, which are well-known bioindicators. This study evaluated the effect of an increase in temperature on the immune response of the subtidal Lytechinus variegatus and the intertidal Echinometra lucunter sea urchins. Both species were exposed to 20 (control), 25 and 30 °C temperatures for 24 h, 2, 7 and 14 days. Counting of coelomocytes and assays on the phagocytic response, adhesion and spreading of coelomocytes were performed. Red and colorless sphere cells were considered biomarkers for heat stress. Moreover, a significant decrease in the phagocytic indices and a decrease in both cell adhesion and cell spreading were observed at 25 and 30 °C for L. variegatus. For E. lucunter, the only alteration observed was for the cell proportions. This report shows how different species of sea urchins respond immunologically to rising temperatures.     

Etmopterus alphus n. sp.: a new lanternshark (Squaliformes: Etmopteridae) from the south-western Indian Ocean

A new species of lanternshark, Etmopterus alphus (Squaliformes: Etmopteridae), is described from the south-western Indian Ocean. The new species resembles other members of the ‘Etmopterus lucifer’ clade in having linear rows of dermal denticles and most closely resembles E. molleri from the south-western Pacific. The new species is fairly common along the upper continental slopes off central Mozambique, at depths between 472 and 558?m, and is also found on the southern Madagascar Ridge in 650–792?m depth. It can be distinguished from other members of the E. lucifer clade by a combination of characteristics, including arrangement of flank and caudal markings, dimension of flank markings and shape, size and arrangement of dermal denticles along the body. Molecular analysis further supports the distinction of E. alphus from other members of the E. lucifer clade.     

Spatial segregation of two common Gobius species (Teleostei: Gobiidae) in the northern Adriatic Sea

The habitat characteristics and spatial segregation of the two common gobies Gobius fallax Sarato, 1889 and Gobius auratus Risso, 1810 were investigated by fish frequency and abundance estimates through visual counts in the northern Adriatic Sea. The latter species is represented by a recently described, unusual colour morph in the northern Adriatic Sea. Gobius fallax was observed at five of the nine locations examined and its abundance did not differ between two of three transect locations at Piran (Slovenia) and at the western coast of Cres (Kvarner region, Croatia). Gobius auratus was not found in the Gulf of Trieste but was present at several Kvarner locations, and co‐occurred with G. fallax at one location at Cres. Both inhabit rocky substrates but they show different preferences for substrate inclinations and bathymetric segregation. Gobius fallax was most frequent between 2 and 8 m depth and was most abundant on substrate inclining less than 30°. Its highest abundance over entire transects was 0.3 indiv.·m^?2 but within certain transect sections this increased to 1.25 indiv.·m^?2. Gobius auratus attained its highest abundance in depths below 8 m and at substrate inclinations between 30 and 90°. This species attained its highest values at the western coast of Cres, where it reached a maximum of 1.5 indiv.·m^?2 over entire transects but even up to 3.0 indiv.·m^?2 in certain transect sections. At Krk, the maximum abundance over entire transects was only 0.3 indiv.·m^?2.     

Studies on the larva of Oniscigaster wakefieldi (Ephemeroptera: Siphlonuridae) in Waitakere stream,Auckland

The larva of the primitive mayfly Oniscigaster wakefieldi, McLachlan 1873 (Ephemeroptera: Siphlonuridae) was studied in the Waitakere Stream, near Auckland, New Zealand, over a 17‐month period extending from July 1965— November 1966. A wide‐mouthed dragnet enabled monthly samples (average 46 specimens) to be collected for detailed studies of the larval growth pattern; this collecting method revealed that the species, previously thought to be rare, is numerous both in the study area and elsewhere in North Island, New Zealand.

O. wakefieldi has a univoltine life cycle with 20–25 larval instars. The larvae prefer different habitats according to their age and can be divided into three distinct groups: larvae 1–10 mm in length are found on finer sediments in quiet shallow water; 11–18 mm in length inhabit waters up to 50 cm deep where the substratum is mainly of pebbles (0.4–4.0 cm diameter) set in a silt matrix; and mature larvae 19–26 mm in length are found adjacent to dry emergent boulders, often at the base of riffles.

Three larval characters are described for the first time to separate the larvae of O. wakefieldi and O. distans. Sexual dimorphism is evident in O. wakefieldi populations by size difference; in the last larval instar, females average 4 mm longer than males. The known distribution of the species in North Island is illustrated.     

南极夏季南设得兰群岛周边海域浮游动物优势种群的分布、丰度及种群结构分析

根据2013/2014年夏季在南极南设得兰群岛周边海域使用北太平洋网采样品及同步环境调查资料,分析了南极大磷虾(Euphausia superba)、拟长臂樱磷虾(Thysanoessa macrura)、尖角似哲水蚤(Calanoides acutus)和近缘哲水蚤(Calanus propinquus)这四种优势浮游动物的丰度和分布特征。结果表明,南极大磷虾和拟长臂樱磷虾在南设得兰海域均有较为广泛的分布,其中南极大磷虾丰度较高,且它们的水平分布存在一定程度的空间分离。在研究海域东部的南奥克尼群岛(South Orkneys)邻近海域发现了大量的南极大磷虾原蚤状C期幼体,表明大磷虾曾于1月中上旬左右产卵繁殖。研究海域的东部南极大磷虾种群结构以幼体前期为主,而西部的种群结构则以幼体后期、未成体和成体为主。尖角似哲水蚤和近缘哲水蚤的空间分布也较为广泛,且两者分布基本一致。东部南奥克尼群岛临近海域的浮游植物浓度较低,这可能是大量南极大磷虾幼体和桡足类摄食活动的结果。     

Recognition of marine spiny lobsters of the Jasus lalandii group (Crustacea : Decapoda: Palinuridae)

All species of Jasus inhabit continental or island waters of the Southern Ocean.

The are six species in the J. lalandii group which contains all but one of the known species of Jasus. Within the J. lalandii group two subgroups, each comprising three species, are recognised. Taxonomic variation is discussed and a key for identification presented. For efficient management, administrators should know the geographic limits of species on which fisheries are based.     

Phenotypic plasticity of Vermetidae suspension feeding: a potential bias in their use as Biological Sea-Level Indicators

Some organisms represent useful Biological Sea‐Level Indicators (Bio SLI) thanks to their constant position relative to sea level and allow the reconstruction of past sea level changes. The sessile gastropods Vermetidae are among the most used indicators, since their shells often resist time averaging and can be easily dated with ¹⁴C. However, all these vermetids have a level of precision (± 0.5–1 m), obtained from data on the Mediterranean Dendropoma petraeum (Monterosato, 1884). We found a certain degree of plasticity in this species; it can also live subtidally, not in correspondence with the main sea level, where it feeds adopting a mixed feeding strategy. Considering this variability and the almost complete lack of knowledge for other Bio SLI vermetids, it appears clear that a common value of precision cannot be maintained and the precision of other vermetid species remains to be tested.     

Cold-seep assemblages on a giant pockmark off West Africa: spatial patterns and environmental control

A giant pockmark colonised by dense cold‐seep assemblages near 3160 m depth along the Congo‐Angola margin has been surveyed by the ROV Victor 6000. The quantitative distribution of chemosynthetic communities was mapped along the dive tracks from a video study using GIS and image mosaicking. Several types of faunal assemblages, either dominated by bivalves of the families Mytilidae (Bathymodiolus sp.) or Vesicomyidae (Calyptogena sp., ‘Vesicomya’ aff. chuni), or by Siboglinidae polychaetes (Escarpia southwardae) were mapped over the 800‐m diameter pockmark area and sampled for fauna, water and sediment. The isotopic analyses (δ¹³C) of tissues from symbiont‐bearing species were within the range typical of nutrition via symbiosis using methane for mussels and sulphide for vesicomyids and siboglinids. The living chemosynthetic communities were distributed on a SW‐NE axis, corresponding to the expression at the sediment surface of a main buried channel providing fluids to the pockmark. The site was characterised by a more active central part in a depression with abundant carbonate concretions where high‐density clusters of siboglinids and mytilids dominate. Large fields of dead and live vesicomyids with a lower mean density were observed in the external areas. The mean coverage of each of the three symbiotic taxa in these two contrasted areas was estimated from mosaic analysis and was up to 30% in the central area dominated by E. southwardae bushes (23%). Symbiont‐bearing species distribution was consistent with methane concentrations in seawater that were generally higher in mytilid beds than in the vicinity of siboglinids and vesicomyids. A Principal Component Analysis performed on environmental factors at the ten sampling sites revealed that 37% of the observed variance in the distribution of symbiont‐bearing species may be explained by variation in both methane and oxygen concentrations, while a Canonical Redundancy Analysis selected methane concentration as the only variable which explains symbiont‐bearing species densities. This spatial distribution of chemosynthetic species at the pockmark scale may reflect temporal patterns of succession of both substrate and fauna, and may be related to different individual pockmarks visible on the microbathymetry mapped using ROV data.     

DNA and morphological identification of an invasive swimming crab,Charybdis japonica,in New Zealand waters

Mitochondrial DNA sequences were used to identify an invasive swimming crab found in Waitemata Harbour, New Zealand. A 457 base sequence of the cytochrome oxidase 1 gene was compared in New Zealand specimens and nine species of Charybdis from Australia and Asia. The New Zealand specimens aligned with C. japonica. The diagnostic morphological characters of C. japonica were also checked in 54 specimens of the species collected in Waitemata Harbour, and concur with the mtDNA result. This is the first record of C. japonica establishing populations outside its native range. C. japonica, along with C. hellerii and the Lessepsian migrant C. longicollis, are the only known invasive species of Charybdis. C. japonica and C. hellerii are two of the few Charybdis species that inhabit the intertidal zone, and it is likely that the intertidal characteristics of these species contribute to their success as invasive species.     

Similar reproductive cycles and life-history traits in congeneric limid bivalves with different modes of nutrition

We have studied two congeneric limid bivalves, Acesta species novum and Acesta excavata (Bivalvia: Limidae), that live in similar physical conditions but use different food sources. Acesta sp. nov. live on the giant siboglinid tubeworm Lamellibrachia luymesi at cold seeps and feed on their eggs, a continuous food source that ultimately is derived from chemosynthesis, whereas A. excavata relies on planktonic food of photosynthetic origin, which varies seasonally. We hypothesized that these two species might show differences in the periodicity of reproduction; specifically, we predicted that A. sp. nov. would breed continuously and that A. excavata would demonstrate an annual reproductive cycle. Our hypothesis was refuted, as both species have a semi‐continuous reproductive cycle. Food quality, quantity or seasonality had no clear effect. Reproductive adults are functionally gonochoristic. Females broadcast buoyant eggs with an average size of 179 μm in A. sp. nov. and 160 μm in A. excavata. Both the size of the larval shell and the size of the spawned eggs are suggestive of pelagic lecithotrophic development. Both species also appear to be protandric hermaphrodites, changing from male to female at approximately 77 and 90 mm shell height, respectively, although not all individuals change sex. In the material investigated in this study there was a biased sex ratio favouring males.     

Grazing preferences of marine isopods and amphipods on three prominent algal species of the Baltic Sea

Preference tests were performed over a two-week period in September 2001 in which isopods (Idotea baltica) and amphipods (Gammarus oceanicus) were offered choices of three common species of algae from the Baltic Sea: Enteromorpha intestinalis, Cladophora spp., and Fucus vesiculosus. After a 48-hour starvation period, 20 individuals of each grazer species were placed in aquaria containing approximately 1.0 g of each algal species. Fifteen trials for each grazer species were run for 20 hours. We found that G. oceanicus ate significantly more Cladophora spp. and E. intestinalis than F. vesiculosus (p<0.001), with a preference order of: Cladophora spp.>E. intestinalis>F. vesiculosus. Similarly, I. baltica ate significantly more of both the filamentous green algae than F. vesiculosus (p<0.001), with a preference order of: E. intestinalis>Cladophora spp.>F. vesiculosus. Given the preference of isopods and amphipods for filamentous green algae, we might expect these algae to be maintained at low biomass levels. However, this is clearly not the case in the Baltic Sea. Nutrient enrichment (bottom-up effects) is the accepted dominant reason for the non-controlling impact of algal grazers, but other reasons may include cascading trophic effects resulting from the removal of large piscivorous fish (top-down effects).     

中国近海爱尔螺亚科九新记录(腹足纲:骨螺科)

提要为了全面了解中国沿海骨螺科(Muricidae)、爱尔螺亚科(Ergalataxinae)的物种数量、分布状况和生活习性,完成中国沿海骨螺科的系统分类学研究,采用传统的形态分类方法,对中国科学院海洋研究所历年来在我国沿海采集的骨螺科标本进行整理、分类,共鉴定出爱尔螺亚科7属,18种,其中9种为中国新记录。爱尔螺亚科主要分布于印度-西太平洋暖海区,通常栖息于潮间带至浅海水深5—200m左右的岩礁、沙、泥沙或砂砾质海底。作者依据Houart等(1995,2004)报道的分类方法,对我国沿海分布的爱尔螺亚科部分归属及种名使用混乱的种,如珠母爱尔螺Ergalatax margariticola、黄口帕斯螺Pascula ochrostoma、筐格螺Muricodrupa fiscella等常见种重新分类,分别将其归属于爱尔螺属(Ergalatax)、帕斯螺属(Pascula)和格螺属(Muricodrupa)。     

人工培育长毛对虾亲虾的实验研究

长毛对虾(Penaeus penicllatus)是福建、广东、广西和台湾的重要经济虾类,其增养殖业目前所遇到的主要困难之一是亲虾的人工培育,这个问题不解决,该养殖业的发展将会受到影响。基于此,我们做了人工培育长毛对虾亲虾的实验,以求探索解决这一问题的途径。     

The cytochrome P450 1A1 response in fish: application of immunodetection in environmental monitoring and toxicological testing

We have developed polyclonal and, recently, monoclonal antibodies against the aromatic hydrocarbon-inducible P450 1A1 form purified from Atlantic cod (Gadus morhua). A simple, indirect enzyme-linked immunosorbent assay (ELISA) based on these antibodies has been developed in our laboratory and tested in numerous experiments with both field-collected and laboratory-exposed fish of different species. The exposure situations studied to date include complex mixtures such as polychlorinated biphenyls (PCBs), dioxins and water-soluble oil fractions, as well as defined compounds such as CB congeners, TCDD, and pesticides. Factors affecting the induction response, including sexual maturation and dietary factors, have also been investigated. The ELISA technique generally shows good correlation with contaminant exposure and catalytic measurements, but has also given new and important information in certain cases where catalytic measurements failed to reveal effects.