Cominella Glandiformis Research Articles

Coastal Ecosystem and Trophic Relationship Of Associated Macrobenthos in Guang-Guang, Mati City, Davao Oriental

Coastal ecosystems are where land and water converge creating a distinct environment hosting a rich diversity of marine organisms. This study aimed to determine the zonation pattern of mangroves and the trophic relationship among the associated macrobenthos in the local coastal ecosystem of Guang-guang, City of Mati, Davao Oriental. The establishment of the study area and gathering of field data were conducted on December 2, 2017, a period of one day during low tide. There was an absence of zonation pattern on the mangal due to Rhizophora stylosa being the only mangrove species present. The marine gastropods observed on the mangal were Monilea callifera, Pomalea canaliculata, Crassostrea iredalei, Trochus pyramis, Spisula solidissima, Zeacumantus lutulentus, Cominella glandiformis, Diloma subrostrata and Haustrum scabina. On the adjacent intertidal zone, the seagrasses and macroalgae found were Enhalus acoroides, Thalassia hemprichii, Padina gymnospora, Halophila ovalis, and Halimeda sp., and the presence of the associated macrobenthos starfish, hermit crab, Philippine sand dollar, mud crab, blue mussel, marine gastropod, shrimp, brittle star, fish and jellyfish. The area had a high macrobenthic diversity with 1.34 on the Shannon-Wiener diversity index and 0.6 on Simpson’s diversity index. On the highest trophic level of the coastal ecosystem food chain are the producers including mangroves, sea grasses and algae and the lowest on the trophic level are the tertiary consumers and apex predators are birds, turtles, and larger fishes.

Population structure of the New Zealand whelk, Cominella glandiformis (Gastropoda: Buccinidae), suggests sporadic dispersal of a direct developer

AbstractWe examined phylogeographic structure in the direct-developing New Zealand endemic intertidal mud whelk, Cominella glandiformis. Two hundred and ninety-six whelks from 12 sites were collected from sheltered shores around New Zealand’s four largest islands (North Island, South Island, Stewart Island and Chatham Island), encompassing the geographical range of this species. Despite being direct developers, gene flow among C. glandiformis populations may occur over short distances by adult floating, and over larger distances by rafting of egg masses. Primers were developed to amplify variable microsatellite regions at six loci. All loci were variable, with 8–34 alleles/loci. Observed and expected heterozygosities were high across all alleles, with minimal evidence of null alleles. The average number of alleles varied from 3.5 (Chatham Island) to 7.5 (Waitemata Harbour). Strong genetic structure was evident, with distinct ‘eastern’ and ‘western’ groups. Each group extended over a large geographic area, including regions of unsuitable habitat, but were linked by oceanic currents. We suggest that the intraspecific geographic genetic structure in C. glandiformis has arisen due a combination of ocean currents (promoting gene flow between geographically distant regions) and upwelling areas (limiting gene flow between certain regions).

Morphology and molecules resolve the identity and life cycle of an eye trematode, Philophthalmus attenuatus n. sp. (Trematoda: Philophthalmidae) infecting gulls in New Zealand.

Trematodes of the genus Philophthalmus are cosmopolitan parasites that infect the eyes of birds and mammals. They have the potential to affect the survival of their hosts and a few cases of human philophthalmiasis have occurred worldwide. Adults of known Philophthalmus species have never been recorded from bird hosts in New Zealand, despite their cercarial stage being a focus of various studies. Here, we describe a new species of Philophthalmus infecting New Zealand red-billed and black-backed gulls, Philophthalmus attenuatus n. sp. It is distinguished from other marine species of Philophthalmus by its long, thin body shape, consistently longer vitelline field on the left, and its body reflexed at the ventral sucker. We use molecular methods to complete the life cycle of this species, matching it with the larval stage infecting the mud whelk, Zeacumantus subcarinatus, and present a preliminary cox1 phylogeny. In addition, we comment on the validity of some taxonomic characters used to differentiate species of this genus, discuss potential colonisation routes to New Zealand and comment on the potential for zoonotic infection.

Molluscan death assemblages from uplifted Holocene terraces, Mahia Peninsula, New Zealand, interpreted from present-day intertidal ecology

Beu, A.G., August 2016. Molluscan death assemblages from uplifted Holocene terraces, Mahia Peninsula, New Zealand, interpreted from present-day intertidal ecology. Alcheringa 41, xxx–xxx. ISSN 0311-5518.Macrofossils from cover beds of marine terraces at Table Cape, Mahia Peninsula, uplifted coseismically ca 250, 1400, 1850 and 3500 years ago are compared with the fauna living on the nearby 200-m-wide intertidal rock platform. The inner platform is dry at low tide, apart from shallow pools containing Diloma aethiops and abundant but unexpected specimens of Zeacumantus subcarinatus and Cominella glandiformis exposed to the sun; all are common fossils in the terrace cover beds. The outer platform is carpeted densely with the alga Hormosira and shelters a diverse fauna, again all common fossils in the terrace cover beds. Sand and gravel containing shell fragments and supporting Zostera sea-grass turf unexpectedly covers ca 5% of the platform in low areas along the east coast. The fossil fauna is listed from 47 samples from two trenches excavated east–west and north–south through the terrace cover beds. Death assemblages of 158 molluscs, including 24 new records as fossils, and 11 taxa in other phyla delimit sediment derived from four shell accumulation sites identified around the present cape: storm beach, high-tidal strand line, hollows in the rock platform and Zostera flats. Up to 32 of the 47 samples (68%) possibly were deposited in Zostera flats; the rest were sand beach accumulations deposited at and near the high-tidal strand line. All fossils common in the cover beds lived on the rock platform. Differences between the deposits in the two trenches result from two factors. Protection along the east coast by protruding tephra beds and an outer rampart armoured with the macroalga Durvillaea prevented erosion of Zostera-supporting sediment which, therefore, was retained after each uplift event. The exposed eastern position of Table Cape also caused sediment to be transported predominantly westwards, onshore on the east coast but away from Table Cape along the north coast.A.G. Beu [a.beu@gns.cri.nz], Paleontology Department, GNS Science, PO Box 30368, Lower Hutt 5040, New Zealand.

Assimilation of organic matter by two benthic consumers across gradients of latitude and nutrient enrichment

In modifying the traits of producers, coastal development and latitude may influence the assimilation of organic matter resources by consumers. The aim of the present study was to assess spatial variation across gradients of latitude and diffuse nitrogen loading in: (1) the N content of the seagrass Zostera muelleri and the mangrove Avicennia marina; and (2) the ultimate organic matter sources (inferred from δ15N and δ13C signatures) of the detritivorous mud whelk Pyrazus ebeninus and the predatory polychaete Nephtys australiensis. It was hypothesised that the organic matter sources of each of the two consumers would vary spatially, following patterns of spatial variation in the N content of primary producers. Sampling in 12 estuaries of New South Wales, Australia, spanning 7° of latitude and variable nutrient loading revealed that the nitrogen content of Z. muelleri was negatively correlated with latitude and nitrogen loading, but the nitrogen content of A. marina leaves followed only latitude. Of the four organic matter sources considered by the present study, Z. muelleri was consistently the main source passed through the trophic chain to the detritivore P. ebeninus and the predator N. australiensis. Nevertheless, the proportionate contribution of Z. muelleri and microphytobenthos to the carbon sources of N. australiensis varied with latitude, the former negatively and the latter positively. These relationships suggest that latitude may influence carbon sources of consumers by modifying producer physicochemical traits.

First records of the Australian dog whelk, Nassarius (Plicarcularia) burchardi (Dunker in Philippi, 1849) (Mollusca: Gastropoda) from New Zealand

Nassarius (Plicarcularia) burchardi (Dunker in Philippi, 1849) is a common dog whelk in subtropical and temperate regions of Australia. In April 2009, two shells of this species were found in the central Waitemata Harbour, Auckland. On the 22 June 2009, a live specimen was found at an intertidal site near Henderson Creek on the western central section of the harbour. Between August 2009 and February 2010, a further 21 living specimens in a range of sizes were found across multiple sites in the central Waitemata Harbour. This species is currently adventive and its presence in the Waitemata Harbour suggests accidental introduction from Australia and subsequent survival. If this species becomes firmly established in New Zealand, there may be significant interactions with native species such as Cominella glandiformis (Reeve, 1847), with which it may directly compete for food, and the invasive mussel Musculista senhousia (Benson in Cantor, 1842), which it is known to eat.

Effects of urban wastewater on crab and mollusc assemblages in equatorial and subtropical mangroves of East Africa

Mangrove forests are known to accomplish crucial ecosystem functions and services. They are nursery areas for fish, prawns and crabs, which provide coastal communities with a variety of food, timber and chemicals, and protect coasts from catastrophic events, such as tsunamis. Recently, a novel ecological service has been proposed for mangrove systems, namely natural wastewater treatment wetlands. This hypothesis was based on experimental data collected mainly in Chinese mangrove systems, which proved that mangrove soils were efficient in absorbing nutrients. Moreover, sewage loading seemed harmless to both plants and benthic communities in these systems. However, before promoting the use of natural mangroves as pollution buffers, or constructed mangrove wetlands as sewage treatment facilities, more data are needed on their overall tolerance to organic loading. Differences in macrobenthos patterns were thus investigated between peri-urban mangroves and sites not affected by sewage disposal in East Africa. We assessed differences in epifaunal assemblages, comprising crabs and molluscs, employing multivariate ACI unbalanced analyses to compare peri-urban mangrove swamps with those characteristic of non-urban mangroves with similar ecological traits. The sampling design was spatially nested, replicates being assessed at equatorial (southern Kenya) and subtropical (southern Mozambique) sites. The results manifested a consistent increase in crab biomass at the peri-urban sites in both Kenya and Mozambique. Moreover, the peri-urban systems were richer than the non-urban mangroves, both in terms of fiddler crabs ( Uca spp.) which feed on benthic microalgae and bacteria, and sesarmids, such as Perisesarma guttatum and Neosarmatium meinerti, which feed on both substratum and leaf litter. The abundance of gastropods, in contrast, decreased significantly, especially in Kenya, mainly due to the disappearance of the mud whelk Terebralia palustris. The results thus indicate that, in East African mangrove systems, domestic wastewater has detectable effects on crabs and molluscs, suggesting their usefulness as bioindicators of its effects in mangroves. Transformed benthic patterns at the peri-urban sites indicated the need for further study of the actual potential of natural mangrove forests to absorb pollution in sewage treatment.

Feeding preferences and food searching strategies mediated by air- and water-borne cues in the mud whelk Terebralia palustris (Potamididae: Gastropoda)

The gastropod T. palustris is one of the major species responsible for leaf consumption and degration within the Indo-Pacific mangrove forests, and it strongly competes with herbivorous sesarmid crabs in consuming fallen leaves. This snail feeds at high and low tides and it is able to locate food items by means of chemical cues. The aim of this study was to assess the food preferences of T. palustris and to define its feeding strategies at low and high tides, by conducting field trials on water-borne mediated food location at high tide, grazing rate and the chemical attraction exerted by different mangrove leaves. The results showed that T. palustris was able to perceive underwater grazed leaves. In addition, we demonstrated that T. palustris consumes all the mangrove species (preferentially the Rhizophoraceae leaves) but Xilocarpus granatum. Moreover, this snail is differentially attracted to different mangrove species: the major attractive power is wielded by the rhizophoracean species and Pemphis acidula, while X. granatum does not attract this snail at all. The efficacy and adaptive value of a chemically mediated food searching strategies is unquestionable since by using this ability T. palustris can locate and reach the leaves it preferentially consumes. Moreover, T. palustris is the only macrobenthic species of East Africa mangroves able to search, detect and consume mangrove leaves at both high and low tides. Such an expanded feeding window permits T. palustris to occupy temporal niches left empty by the sesarmid crabs.

Parasitism can influence the intertidal zonation of non-host organisms

Zonation of organisms in soft-bottom intertidal habitats is mainly a consequence of the tidal sorting of the substrate and how benthic organisms respond to it, with predation and competition also playing a role. Although parasites are ubiquitous in these habitats and known agents of community structure, their impact on zonation is rarely considered. Here, using observational and experimental data, we show that parasitism of the cockle Austrovenus stutchburyi by echinostome trematodes has both direct and indirect effects on the zonation of four other animals associated with cockles on a New Zealand tidal flat. The trematodes encyst in the foot of cockles, leaving heavily infected cockles unable to bury and lying exposed on the sediment surface. Whereas cockle density peaks in the mid intertidal zone, both infection intensity by trematodes and density of surfaced cockles increase linearly towards the shore; this influences the vertical zonation of animals attaching to or feeding on cockles. First, the relative abundance of the whelk Cominella glandiformis increase exponentially shoreward, as does its rate of predation on cockles; the effect of the parasite on the cockles’ burying ability has thus shifted the peak abundance of whelk predators towards the upper tidal level, away from peak cockle densities. Second, the density of the anemone Anthopleura aureoradiata, corrected for the availability of its cockle substrate, peaks in the lower intertidal zone, although a transplantation experiment revealed that anemones can survive higher up the shore if attached to buried cockles. Anemones on exposed cockles are susceptible to desiccation, and thus again the parasite-induced surfacing of cockles at higher tidal levels plays a role by decreasing substrate availability for anemones. Third, densities of the limpet Notoacmea helmsi increase rapidly toward higher tidal levels, where limpets graze the surfaces of empty cockle shells or live surfaced cockles. The availability of both substrates used by limpets is influenced either directly (surfaced cockles) or indirectly (empty shells, via whelk predation) by parasitism. Fourth, the fish Notolabrus celidotus feeds on cockles by cropping their foot. Although the lower intertidal is submerged for longer and cockle densities peak in the mid intertidal, the frequency of foot-cropping by fish peaks in the upper tidal levels, where parasitism maintains a high density of surfaced cockles. Our results are the first demonstration that parasitism of a key species can influence the zonation of non-host organisms, a phenomenon likely to occur in other systems.

Intertidal facilitation and indirect effects: causes and consequences of crawling in the New Zealand cockle

Bioturbation by the ghost shrimp Callianassa filholi and the lugworms Abarenicola affi- nis as well as coverage by macroalgae cause the New Zealand cockle Austrovenus stutchburyi (Veneridae) to relocate by crawling longer distances on the sediment surface. On the surface, the cockles become targets for sublethal predation by benthic-feeding fishes, which crop off their feet. This renders the cockles unable to bury for up to 8 wk, thus exposing them to a 5-fold higher preda- tion pressure from shorebirds and the whelk Cominella glandiformis than buried conspecifics. Shell dimensions, foot size, general condition, gender, age, and infections by gymnophallid trematodes do not influence the crawling activity of cockles. However, heavy infection by the digenean trematode Curtuteria australis and the shell-boring spionid polychaete Boccardia acus reduces the distance travelled, and these organisms may hence reinforce the impact of the biogenic disturbers by forcing repeated crawling of the cockles to reach an undisturbed site. The presence of biogenic disturbers and some parasites therefore benefits predating fishes by providing them with an otherwise inacces- sible food source, and these in turn benefit birds and whelks through foot-cropping, thus increasing the availability of prey. The gymnophallids also receive an advantage through transmission success to their definitive shorebird hosts. The question as to whether Curtuteria australis benefits, depends on the balance between its loss to fishes (unsuitable hosts) and its increased trophic transmission to its bird hosts. The spionid B. acus on the other hand is negatively affected, since its fate is linked to that of its substrate, which is the shell of the cockle. If the cockle is predated, the attached B. acus will perish also.

A Gastropod Scavenger Serving as Paratenic Host for Larval Helminth Communities in Shore Crabs

The whelk Cominella glandiformis is an important predator-scavenger of New Zealand intertidal ecosystems; a few whelks can quickly eat all the soft tissues of recently dead crabs. In this study, we demonstrate that whelks can also ingest and act as paratenic hosts for at least 4 helminth species that use crabs as intermediate hosts: metacercariae of the trematode Maritrema sp. and of another unidentified trematode, larval acuariid nematodes, and cystacanths of the acanthocephalans Profilicollis spp. Large whelks ingest disproportionately more helminth larvae than small whelks, but the survival of parasites during their short stay in the whelks is not affected by whelk size. The majority of metacercariae and nematodes are passed out in whelk feces within 3 days of ingestion, whereas the few cystacanths found did not leave whelks until after that time; no parasite was left in whelks 5 days postingestion. Survival of all 4 helminth species was generally very high, though it decreased day by day in 2 species. Given that the avian definitive hosts of all 4 helminths also eat whelks, our results indicate that alternative transmission pathways exist and that parasites can take routes through food webs that are too often ignored.

From first to second and back to first intermediate host: the unusual transmission route of Curtuteria australis (Digenea: Echinostomatidae).

The trematode Curtuteria australis uses the whelk Cominella glandiformis as first intermediate host and the cockle Austrovenus stutchburyi as second intermediate host before maturing in shorebirds. The whelk also happen to be an important predator of cockles on intertidal mudflats. In this study we show that whelks can act as temporary paratenic hosts for the trematode. A single whelk feeding on 1 cockle can ingest large numbers of metacercariae, which remain within the whelk for 1-3 days before passing out in feces. The viability of these metacercariae assessed as the percentage capable of successfully excysting under conditions simulating those inside a bird's digestive tract, is lower after passage through a whelk (48%) than before (59%). Still, given that shorebird definitive hosts prey on whelks as well as cockles, survival inside the whelk allows C. australis to complete its life cycle: overall, though, whelk predation is likely to be an important sink for the trematode population. To our knowledge, this is the first report of a trematode using a snail as both first intermediate host and paratenic host, offering an alternative transmission route for the parasite as a result of the unusual trophic relationships of its hosts.

Spatial heterogeneity in parasite loads in the New Zealand cockle: the importance of host condition and density

Samples of the New Zealand cockle Austrovenus stutchburyi (Veneridae) collected at two different intertidal levels were found to be heavily infected by the echinostome trematode Curtuteria australis which use the mud flat whelk Cominella glandiformis and shorebirds as first and definitive host, respectively. Parasite loads were on average more than 2-fold higher at the high site than at the low site, whereas the density of Curtuteria australis metacercariae per square metre showed the opposite trend. This pattern appeared unrelated to the abundance of first intermediate hosts and C. australis prevalence within this host that did not differ between sites. At both sites there was a positive relationship between parasite load and cockle condition, a likely by-product of the relationship between condition-based filtration capacity and the rate at which individual cockles encounter the free-swimming trematode larvae. The results suggest that the between-site variation in parasitism is a consequence of the much higher density of cockles at the low site. There, the dense cockle population is able to clear the water column of parasites and consequently individual cockles virtually ‘compete’ for parasite larvae. This will depress mean infection intensity per cockle but elevate mean parasite density per square metre.

DYNAMICS OF AGGREGATIONS OF A GASTROPOD PREDATOR/SCAVENGER ON A NEW ZEALAND HARBOUR BEACH

Observations of a New Zealand harbour beach revealed that aggregative feeding behaviour was common in the buccinid gastropod Cominella glandiformis (Reeve, 1847). The majority of such aggregations are associated with either the tellinid bivalve Macomona liliana (Iredale, 1915) or the venerid cockle Austrovenus stutchburyi (Wood, 1828). Marking experiments indicate that aggregations persist for one tidal cycle. This information, together with the density of aggregations associated with each ‘prey’ species allows the calculation of rate of predation by Cominella glandiformis and of the mortality of M. liliana and A. stutchburyi at different stations on the beach. Averaged over spring periods, when predation and mortality are reduced, and summer, the calculated rates suggest that between 2 to 16% of M. liliana and 3 to 9% of A. stutchburyi fall prey to Cominella each year. The majority of bivalves at the centre of aggregations appeared to be tightly shut and undamaged, suggesting that the gastropods are predators attacking live prey, although late arrivals may be attracted as scavengers by leaking body fluids. Aggregated feeding may provide the gastropod with both competitive and metabolic benefits.

The Mid Pleistocene Waiomio Shellbed (Castlecliffian, c. 550–600 ky), Wanganui Basin, New Zealand

A new outcrop of the Waiomio Shellbed is described from the west bank of the Rangitikei River, near Porewa. The shellbed comprises cross-bedded pebbly-shell conglomerate containing a rich intertidal assemblage of estuarine (Macomona liliana, Cominella glandiformis, Austrovenus stutchburyi) and shore face (Paphies subtriangulata, Mactra discors, Spisula aequilatera, Dosinia (Phacosoma) subrosea) Mollusca. This site contains previously undescribed units, and the names Waiomio Formation (which includes the basal Waiomio Shellbed) and Reu Reu Formation are introduced. The excellent exposure demonstrates the position of the Waiomio Shellbed within a complete cyclothem, facilitating interpretation in terms of sequence stratigraphic concepts. A basal disconformity (sequence boundary) truncating a palaeosol horizon (lowstand systems tract), is overlain by the Waiomio Formation (transgressive systems tract), and is succeeded by the Reu Reu Formation, comprising an in situ shellbed (condensed section) and massive siltstone (highstand systems tract). The complete sequence is compared with its probable equivalent in the Wanganui coast section, which correlates with oxygen isotope stage 15.

Life cycle ofCurtuteria australisn.sp. (Digenea: Echinostomatidae: Himasthlinae), intestinal parasite of the South Island pied oystercatcher

Abstract Curtuteria australis is described from the small intestine of the South Island pied oystercatcher, Haematopus ostralegus finschi. It differs from its three congeners in having 31 collar spines and unbranched excretory arms, and in the extent of vitellaria. The final host and the primary and intermediate hosts were all collected at the Heathcote-Avon estuary, near Christchurch, New Zealand. The primary host is the whelk Cominella glandiformis, the digestive gland of which is invaded by rediae. These give rise to free-swimming cercariae which emerge at water temperatures above 20°c. Cercariae are sucked into the mantle cavity of the cockle Chione stutchburyi, the intermediate host, through the inhalant siphon, and encyst in the muscles of the anterior end of the foot. Metacercariae were fed to day-old domestic chickens, and adult C. australis were retrieved after 5 days. Prevalence in the whelk was 3.2%, in the cockle 63.6%, and in the oystercatcher 50.4%. As in most littoral habitats, the prevalen...

Effects of overcrowding on floating behaviour in the mud whelkcominella glandiformis(Mollusca: Gastropoda)

Abstract The mud whelk Cominella glandiformis (Reeve, 1874) was observed on a tidal flat “floating” upside down beneath the water surface. Study in the laboratory showed that, when C. glandiformis is “floating”, the foot is distended with blood to approximately twice its normal surface area. In the laboratory C. glandiformis “floated” only during daylight hours, and the incidence of “floating” increased markedly as specimens became more overcrowded. Possibly “floating” is a rapid dispersal mechanism in response to overcrowding; it may also assist respiration in the event of overcrowding producing anaerobic conditions. Its occurrence only during daylight hours suggests that a reaction to light may also be involved.

Some Observations On The Life Cycle OfVelacumantus Australis(Quoy And Gaimard)

Summary The Australian Mud Whelk, Velacumantus australis, is common in certain places along the eastern and southern coasts of Australia. Two populations from Narrabeen Lagoon, near Sydney, were studied over the period of one year. Breeding takes place during the summer. Most snails probably breed for the first time at the end of their second year, many die during the next year, but some probably live into their fourth year. Details of the growth of juveniles, and changes in population structure with time, are given.