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Margaritifera monodonta, or the Spectaclecase Mussel, is a federally endangered freshwater mussel species that has experienced a 55% reduction in range and is currently concentrated in 3 ri...

Islamy RA, Hasan V. 2020. Checklist of mangrove snails (Mollusca: Gastropoda) in South Coast of Pamekasan, Madura Island, East Java, Indonesia. Biodiversitas 21: 3127-3134. Mangrove forests are crucial to gastropods providing breeding and nursery grounds, food sources, and shelter from predators. They are useful bioindicators of environmental pollution. Consequently, it is crucial to understand the species richness of gastropods mangrove environments. This study aims to provide information about the species composition of mangrove snails in the South Coast of Pamekasan (Madura Island), East Java, Indonesia. Samplings were performed at low tide from 4 stations in December 2019 using a transect (10m x 10m). All samples were identified using reference books and published journal. We found a total of 10 family consist of Assimineidae, Cerithiidae, Ellobiidae, Littorinidae, Muricidae, Neritidae, Olividae, Planaxidae, Potamididae, and Trochidae with consist of 15 Genus, i.e., Assiminea, Clypeomorus, Cerithium, Rhinoclavis, Laemodonta, Littorarina, Tenguella, Semiricinula, Nerita, Clithon, Oliva, Planaxis, Pirenella, Telescopium, and Monodonta. The most common substrate where mangrove snails were found was rocks, sandy, and around the tree and roots of mangrove. All gastropods in this study found alive during our surveys and predominantly mangrove associated. We assume that there are still many snails that have not been surveyed at the location. We suggest to the future researcher to survey through different sampling efforts and sampling methods such as quantitative or semi-quantitative methods.

glomus, Nassa [Nassarius recidivus (Martens, 1876)] (Figures 21E, F) 1890c: 185 [XXXVIII c: 919]—available name Type material. MCZR–M–30031— 1 sh “ N. glomus Monts Sardegna (Tib.)” + label in Tiberi’s handwriting “ Nassa semistriata (Bucc.), Broc. Fondi coralligeni. Sardegna viv.te” Type locality. Described from Sardinia (Italy). Remarks. Recorded by MolluscaBase (2018) as a synonym of Nassarius recidivus (Martens, 1876)., Published as part of Appolloni, Massimo, Smriglio, Carlo, Amati, Bruno, Lugliè, Lorenzo, Nofroni, Italo, Tringali, Lionello P., Mariottini, Paolo & Oliverio, Marco, 2018, Catalogue of the primary types of marine molluscan taxa described by Tommaso Allery Di Maria, Marquis of Monterosato, deposited in the Museo Civico di Zoologia, Roma, pp. 1-138 in Zootaxa 4477 (1) on page 58, DOI: 10.11646/zootaxa.4477.1.1, http://zenodo.org/record/1454652

Anatomical data on Solariellaobscura (Couthouy, 1838) are presented and analyzed. The main features of this species, when compared with other known trochoids, are: ctenidium with thick lamellae; enlarged ureter (that may indicate sexual dimorphism) instead of a modified urogenital papilla; odontophore very different from other trochoids such as Calliostoma, Agathistoma, Monodonta, and Gaza, with short m6, large mj and m4 pairs and absent m8 pair and posterior cartilages; esophageal valve surrounding the odontophore ventrally; anterior and mid-esophagus composed of several thin folds and a very wide cerebral ganglion. Solariellaobscura differs from Solariellavaricosa (Mighels & Adams, 1842) by having lower spire, spiral cords weaker on the base and axial rib oblique. There are no differences between S.obscura and S.varicosa in the external morphology and radula. These internal anatomical data are described for the first time for a solariellid and might improve our understanding of the relationships within this taxon.

2 of Ulva frond, hole areas ranged from 0.37 to 5.94 cm 2 , and between 4.9 and 36.2 holes were observed. Fourteen residential animal species were observed at the three evaluated sites, 75.0 (Haseom) to 408.7 individuals 100 g -1 Ulva (Pohang) per site. The dominant residential species at each site differed with Amphithoe sp. at Haseom, Monodonta spp. at Pohang, and Pagurus sp. at Woedo. The growth (frond area, wet weight) and hole number of Ulva fronds, and the number of residential animals were significantly greater in samples collected from the sheltered shore than the wave-exposed shore of Seongsan. The present results showed U. australis grew well at sheltered shores and had more holes on the fronds due to abundance of residen- tial animals. The dominant residential animals (crabs, gammaridea, and snails) were similar in the Ulva populations of sheltered and wave-exposed shores, but greater species diversity was observed at the exposed shore (18 species ver. 11 species). In conclusion, U. australis is a keystone species providing habitat to various invertebrates and frond holes are positively correlated to the number of residential animals.

The presence of thin organic layers embedded in the nacreous layer in the shell of several species of Unionoida has been widely considered to be largely a reaction to prevent further shell dissolution once part of the shell has been corroded. Their microstructural characteristics have also been used as taxonomic characters to separate the families Margaritiferidae and Unionidae. This paper focuses on the description and interpretation of these organic layers in samples of four extant species of European Unionidae coming from acidic and alkaline waters, six extant species of Margaritiferidae, one Cretaceous Unionidae and two Cretaceous Margaritiferidae species. Our results demonstrate that organic layers have characterized species of Unionoidea at least since the Cretaceous and occur in specimens coming from both acidic and alkaline waters. Moreover, the presence of these layers in noncorroded shells can be interpreted as a preventative or ‘prophylactic’ measure against corrosion. Their thickness is the only useful character verified to separate the two families. In the Margaritiferidae, organic layers were found to be present in Margaritifera margaritifera, M. valdensis, M. idubedae, M. laosensis, M. laevis and M. monodonta, and absent in M. auricularia and M. marocana. In Unionidae, they appear in Protopleurobema numantina, Potomida littoralis and in some individuals of Unio mancus, U. delphinus and U. tumidiformis. We argue that organic layers played a fundamental role in shell protection during the invasion of freshwater by the earliest Unionoida, while today they function to improve fitness in acidic water in some species.

Monodonta sp. Figs 2 B–C Monodonta sp.: Zvonareva et al. 2015: 8. Material examined. Dam Bay, mangrove plantation, 3 specimens. Abundance. Rare. Measurements. Up to 12 mm. Ecological notes. Found on sediment surface in mid intertidal zone. Distribution in Vietnam. Central coast., Published as part of Zvonareva, Sofya & Kantor, Yuri, 2016, Cheсklist of gastropod molluscs in mangroves of Khanh Hoa province, Vietnam, pp. 401-437 in Zootaxa 4162 (3) on page 404, DOI: 10.11646/zootaxa.4162.3.1, http://zenodo.org/record/254973, {"references":["Zvonareva, S., Kantor Yu., Xinzheng, L. & Britayev, T. (2015) Long-term monitoring of Gastropoda (Mollusca) fauna in planted mangroves in central Vietnam. Zoological studies, 54, 1 - 39."]}

Monodonta sp. Figs 2 B–C Monodonta sp.: Zvonareva et al. 2015: 8. Material examined. Dam Bay, mangrove plantation, 3 specimens. Abundance. Rare. Measurements. Up to 12 mm. Ecological notes. Found on sediment surface in mid intertidal zone. Distribution in Vietnam. Central coast.

Monodonta australis Lamarck, 1822 Monodonta australis Lamarck, 1922 b: 35, no. 11. Dautzenberg, 1929: 538. Viader, 1937: 55. Barnard, 1963 a: 253, fig. 14 c. Kennelly, 1964: 55, pl. 4, fig. 21. Day, 1969: 159. Kensley, 1973: 40, fig. 89. Richards, 1981: 35, pl. 9, fig. 64. Kilburn & Rippey, 1982: 41, pl. 8, fig. 20. Steyn & Lussi, 1998: 22, fig. 70. Jarrett, 2000: 4, fig. 9. Branch et al., 2010: 176, fig. 77.2. Marais, 2011: 64. Type loc.: ‘les mers de la Nouvelle-Hollande’ [the seas of Australia]; holotype in MHNG (1096 / 28), [not discussed by Mermod]. Trochus labio (non Linnaeus, 1758)— Krauss, 1848: 100. Trochus australis — Krauss, 1848: 100. P. Fischer, 1877 in 1875–1880: 227, pl. 74, figs 1, 2. Trochus (Monodonta) australis — Martens, 1880: 296. Bisacchi, 1931: 179. Distribution. Tropical Indian Ocean to E. Cape (East London); intertidal. Notes. Also recorded from Japan (Sasaki 2000)., Published as part of Herbert, David G., 2015, An annotated catalogue and bibliography of the taxonomy, synonymy and distribution of the Recent Vetigastropoda of South Africa (Mollusca), pp. 1-98 in Zootaxa 4049 (1) on page 60, DOI: 10.11646/zootaxa.4049.1.1, http://zenodo.org/record/245367, {"references":["Dautzenberg, P. (1929) Contribution a l'etude de la faune de Madagascar. Mollusca II, Mollusca marina testacea. Faunes des colonies Francais, 3 (4), 115 - 430 (321 - 636).","Viader, R. (1937) Revised catalogue of the testaceous Mollusca of Mauritius and its dependencies. Mauritius Institute Bulletin, 1, i - xiii + 1 - 111, plus map.","Barnard, K. H. (1963 a) Contributions to the knowledge of South African marine Mollusca. Part IV. Gastropoda: Prosobranchiata: Rhipidoglossa, Docoglossa. Tectibranchiata. Polyplacophora. Solenogastres. Scaphopoda. Annals of the South African Museum, 47, 201 - 360.","Kennelly, D. H. (1964) Marine Shells of Southern Africa. First edition. Nelson, Johannesburg, 92 pp., 30 pls.","Day, J. H. (1969) A Guide to Marine Life on South African Shores. Balkema, Cape Town, 300 pp.","Richards, D. (1981) South African Shells - a Collector's Guide. Struik, Cape Town, 98 pp., 60 pls.","Kilburn, R. N. & Rippey, E. (1982) Sea Shells of Southern Africa. Macmillan, Johannesburg, 249 pp., 46 pls.","Jarrett, A. G. (2000) Marine Shells of the Seychelles. Carol Green Publishing, Cambridge, 149 pp.","Branch, G. M., Griffiths, C. L., Branch, M. L. & Beckley, L. E. (2010) Two Oceans. A Guide to the Marine Life of Southern Africa. Revised Edition. David Philip, Cape Town, 456 pp.","Marais, A. (2011) Field Guide to South African Seashells: Cape Region. Centre for Molluscan Studies, Groenkloof, 104 pp.","Linnaeus, C. (1758) Systema naturae. Vol. 1. 10 th Edition. Laurentii Salvii, Holmiae, 824 pp.","Krauss, F. (1848) Die sudafrikanischen Mollusken. Ein Beitrag zur Kenntniss des Kap- und Natallandes und zur geographischen Verbreitung derselben, mit Beschreibung und Abbildung der neuen Arten. Ebner & Seubert, Stuttgart, ii + 140 pp., 6 pls.","Fischer, P. (1875 - 1880) Genres Calcar, Trochus, Xenophora, Tectarius et Risella. In: Kiener, L. C. (Ed.), Species general et iconographie des coquilles vivantes .... J-B. Baillere et fils, Paris, Vol. 11, pp. i - iii, 1 - 480, pls. 1 - 120. [1 - 96, 1875; 97 - 144, 1876; 145 - 240, 1877; 241 - 336, 1878; 337 - 463, 1879 - 80; index 464 - 480]","Martens, E. von (1880) Mollusken. In: Mobius, K. (Ed.), Beitrage zur Meeresfauna der Insel Mauritius und der Seychellen. Gutmann, Berlin, pp. 181 - 352, pls. 19 - 22.","Bisacchi, J. (1931) Alcuni Trochus del Mar Rosso. Annali del Museo Civico di Storia Naturale \" Giacomo Doria \", 55, 176 - 182.","Sasaki, T. (2000) Trochidae. In: Okutani, T. (Ed.), Marine mollusks in Japan. Tokai University Press, Tokyo, pp. 55 - 83."]}

The paper presents and compares the results of microstructural analysis of two different Adriatic Sea shells, both belonging to the species of sea snails, namely the Adriatic Monodonta and the Mediterranean limpet. Although both seashells are coastal marine gastropod molluscs, they do have a very distinctive microstructure. The detailed microscopic analysis has shown that the Monodonta consists mainly of nacre. On the other hand, the limpet’s shell showed a crossedlamellar microstructure, which extends through almost the whole cross section of the shell. Average measured aragonite layers thicknesses are 0.454 and 0.360 um in Monodonta and limpet shell, respectively.

The Mediterranean trochid gastropods currently known as Monodonta mutabilis (Philippi, 1846) and Gibbula richardi (Payraudeau, 1826) are shown, on both morphological and electrophoretic grounds, to be sibling species, and therefore congeneric. The generic name Phorcus Risso, 1826 should be used for these species, which may be more closely related to the Mediterranean Trochocochlea species than to other species classified in Gibbula. The oldest appropriate genus-group name for the Mediterranean species currently classified as Monodonta (M. articulata, M. turbinata) is Trochocochlea MOrch, 1852. The earliest type species designation for Osilinus Philippi, 1847 is that of Trochus constrictus Lamarck, 1822 by Herrmannsen (1847), which would make Osilinus a valid senior synonym of the widely used name Austrocochlea Fischer, 1885 and not of Trochocochlea as commonly accepted. A ruling of the International Commission on Zoological Nomenclature will be sought for the case.

Coastal rock bioerosion research is well established. Otherwise there is the need to improve the way in which bioerosion rates are calculated. Since the findings of McLean (1967), it has been assumed that the dry weight of pellets collected after 24 hours provides an estimate of the amount of organism daily erosion. This is an assumption that relies largely on initial experimental procedures lacking any empirical ascertainment. This paper assess what is the transit time of the rock fragments through the intestine of the gastropod Monodonta articulata, and the implications of applicability of this temporal framework to the computation of a more precise estimation of the bioerosion throughout laboratory experiments. Our results suggest that for the gastropod Monodonta articulata, the major part of the eroded and ingested rock is defecated during feeding time. According to this, the confidence of bioerosion rates values calculated by means of faecal pellet collection based on 24-hour time frame can be concluded. Erosion rates for M. articulata activity in limestone rock samples have been estimated to range between 8.00 mg·ind-1·day-1 to 10.10 mg·ind -1·day-1. © Coastal Education & Research Foundation 2013

Growth of Monodonta lablo (Linne) (Gastropoda: Trochidae) was investigated bimonthly for a period of 1 yr by quadrat sampling and mark-recapture on a moderately exposed boulder shore in Amakusa, South Japan. Linear regression was calculated for shell width at recapture on shell width at release. Growth in the high zone was slower than in the mid and low zones and decreased as shell width increased. Estimated growth curves fit well with the observed growth curves of individual snails. Seasonal growth patterns of juvenile (58 mm) snails may be affected by seasonal fluctuation of micro- algal abundance. Due to reproduction, growth of large snails decreased in summer. Tidal level varia- tion of growth rate caused large variation in growth curves in middle-sized snails (ca 10 rnm shell width), because of their wide range of distribution, which was related to vertical migration on the shore. Simulated growth curves showed that 8 mm snails in the high zone reached asymptotic size (ca 13 mm) 1 yr later than snails in the mid and low zones. In small (ca 6 mm) and large (ca 13 mm) snails, less van- ability in observed growth curves was explained due to their limited ranges of distribution. This study demonstrates that variation in growth rate is attributable to sue-specific distribution on a shore and indicates how migration expands size variation within a single age group.

LT50 values obtained for Monodontaturbinata exposed to heavy metal ions were as follows: 25.2 days after exposure to final concentration of 1.0ppm Cd+2; 21.2 days for 0.1ppm Hg+2; 25.2 for 0. 5ppm Cr+3 and 16.8 days for 0.5ppm Cr+6, compared to 32.8 days for the control. The final concentrations of metal ions in the mollusc tissue increased by 20 times in the Hg+2, and by 10 times in the Cd+2 treated Monodonta, compared to the untreated control. The normal contents of cytochromes be and P450 in Monodontaturbinata digestive gland microsomes were 195±51 and 58±20 nmol/mg protein, respectively. NADPH-cytochrome c reductase activity was 5.9±3.0 nmol/min/mg protein. Exposure to all heavy metal ions had a destructive effect on the two hemoproteins, especially on cytochrome P450, and a pronounced impact on NADPH-cytochrome c activity which was reduced to about 50% in the treated mollusc. No alarming concentrations of metal ions could be detected in Monodontaturbinata collected from different sites along Israel Mediterranean coast.

Bryolimnia MONODONTA Kaye, 1922 Proceedings of the Zoological Society of London 67, 991–998 [993], pl. I: fig. 20. Combination still valid (see Poole 1989). Holotype, male, pinned: Specimen data: “Siparia 16 / 6 / 18 ” [Handwritten (by Lamont)]. “Lamont Collection 1950 - 16 ” [Printed] with label with “ TYPE ” [Handwritten in red ink], glued to it. “Bryolimnia monodonta Kaye ” [Handwritten Lamont cabinet label]. Label bearing justification of its holotype status written by M.J.W.Cook, 1997. Remarks: This specimen collected at Siparia, Trinidad, 16 June 1918, by Sir N. Lamont is unambiguously the holotype and is illustrated in colour in Pl. I: fig. 20 (Kaye 1922, Kaye & Lamont 1927). Poole (1989) erroneously suggests that the [holo] type is in the BM(NH)., Published as part of Bland, Keith P., 2010, Name-bearing Types of Lepidoptera (Insecta), excluding Rhopalocera, in the National Museums of Scotland, Edinburgh, pp. 1-22 in Zootaxa 2394 on page 19, DOI: 10.5281/zenodo.275866, {"references":["Kaye, W. J. (1922) New species of Trinidad Moths. Proceedings of the Zoological Society of London, 67, 991 - 998 + plate I.","Poole, R. W. (1989) Lepidopterorum Catalogus (New Series). Fascicle 118, Noctuidae Parts 1 - 30. E. J. Brill, New York.","Kaye, W. J. & Lamont, N. (1927) A catalogue of the Trinidad Lepidoptera Heterocera (Moths). Memoirs of the Department of Agriculture, Trinidad & Tobago, Port-of-Spain. No. 3, 1927, xv + 144 pp., 2 pls."]}

Several behavioural, physiological and morphological parameters were studied in two marine gastropods to better define niche differences between the species. M. turbiformis is adapted to a broader more variable niche where as M. turbinata has more stringent niche requirements. This study demonstrated that M. turbinata as compared with M. turbiformis has: a) greater foot muscle strength, b) shorter more squat shell form, c) greater body weight per shell weight and d) greater foot size per body weight. M. turbiformis has a) greater resistance to desiccation and low temperature and b) a more slender shell form. Qualitatively, M. turbiformis appears less effected by elevated temperatures to 40° C. In the laboratory, M. turbinata is more sensitive to crowding. In the field, M. turbinata is found principally in high energy situations with respect to surf action or water flow on or over rocks to which it is attached. On the other hand, M. turbiformis is exclusively found in relatively quiet, shallow wat...

Trace elements were analyzed in organisms collected at five sampling stations along coastal areas of Linosa Island, Sicily (southern Tyrrhenian Sea, Italy). Concentrations of Cd, Cr, Cu, Pb, and Zn were measured in Posidonia oceanica L. Delile tissues, the two brown algae Padina pavonica (L.) Thivy and Cystoseira sp., and the two gastropod mollusks Monodonta turbinata Born and Patella caerulea L. Seawater samples were also collected at each site to assess soluble metal concentrations and to gain relevant information on their bioaccumulation ability. Data were processed by multivariate techniques, such as principal component analysis (PCA) and linear discriminant analysis on PCA factors. The scoreplots obtained showed that the pollutant distribution is more significantly correlated with species than with sites. For seaweeds, P. oceanica was associated with higher Cd, Cu, and Zn levels; Padina species had higher Cr concentrations, and Cystoseira had higher Pb levels. For mollusks, Monodonta species had high concentrations of Cu and Cr and Patella species were associated with Cd. Some general metal bioaccumulation patterns are described but no one sampling site was more contaminated than the others. The hypothesis of Linosa island serving as a reference ecosystem for baseline trace metal levels in southern Tyrrhenian areas is indeed supported by the statistical comparison among other southern Tyrrhenian ecosystems performed with Kruskall Wallis and Mann-Whitney tests. For P. oceanica leaves, P. pavonica, M. turbinata, and P. caerulea, this study confirms their usefulness as possible cosmopolitan biomonitors of trace metals in marine Mediterranean areas.

Monodonta turbinata B. and Patella caerulea L. were evaluated as possible biomonitors of trace metal contamination in marine coastal areas. These species are marine gastropod molluscs; they are distributed in all coastal areas of the Mediterranean sea and are easy to identify and available all year round. They have the necessary prerequisites for use as biomonitors. The first aim of this preliminary survey is to evaluate the concentrations of Cd, Cr, Cu, Pb and Zn present in soft tissues of the selected species. Samples were collected in the tidal zone (1-2 meters depth) in a possible reference ecosystem (Linosa island, Sicily, Italy). Five coastal stations were selected according to the species availability. The second purpose was to establish the validity of these two gastropod species as bioaccumulators. The station number 4 (Pozzolana di Ponente) is the only site in Italy where the sea turtle Caretta caretta, annually deposes her eggs; thus this station is of a particular ecological relevance. In order to test the bioaccumulation capabilities of these biomonitors seawater samples were collected in each site to assess soluble metal concentrations and then CFs. Seawater samples were collected appropriately in a 6-month period of sampling in the selected stations. Statistical multivariate analyses, PCA, were applied to test the differences between metal concentrations in different sites and species. Results showed high results (CFs) with respect to the concentrations in marine waters (soluble fraction). This confirmed the suitability of these species for biomonitoring purposes. PCA analysis showed clearly two separated patterns of bioaccumulation (i.e. Patella and Monodonta) and no significant differences (p = 0.05) for trace metal accumulation were obtained between the studied sites. This finding agrees with the hypothesis of this island as reference ecosystem for intraspecific comparison within Tyrrhenian areas. www.witpress.com, ISSN 1743-3541 (on-line) © 2006 WIT Press WIT Transactions on Ecology and the Environment, Vol 88, doi:10.2495/CENV060011 Environmental Problems in Coastal Regions VI 3

Revisão taxonômica das espécies de abelhas do gênero Lestrimelitta Friese (Hymenoptera, Apidae, Meliponina) que ocorrem no Brasil. Com base em caracteres morfológicos, como aqueles relacionados com a pilosidade, o formato do espiráculo propodeal, as distâncias interorbitais e o comprimento do esporão mesotibial, são reconhecidas catorze espécies, seis das quais novas para a Ciência: L. ciliata. sp. nov., L. maracaia sp. nov., L. similis sp. nov., L. spinosa sp. nov., L sulina. sp. nov. e L. tropica sp. nov. São designados lectótipos para Trigona (Lestrimelitta) limao var. rufipes Friese, 1903 e Trigona (Lestrimelitta) limao var. rufa Friese, 1903. O macho de L. limao (Smith, 1863) é descrito pela primeira vez. É apresentada também uma diagnose das seguintes espécies: L. ehrhardti Friese, 1931; L. glaberrima Oliveira & Marchi, 2005; L. glabrata Camargo & Moure, 1989; L. monodonta Camargo & Moure, 1989; e L. nana Melo, 2003. São apresentados chaves de identificação para operárias e machos, ilustrações e mapas de ocorrência. The species of Lestrimelitta present in Brazil are revised. Fourteen species are recognized, six of them described as new: L. ciliata. sp. nov., L. maracaia sp. nov., L. similis sp. nov., L. spinosa sp. nov., L. sulina. sp. nov. and L. tropica sp. nov. The main morphological characters used to distinguish the species are pubescence, shape of the propodeal spiracle, the interorbital distances and size of the midtibial spurs. Lectotypes for Trigona (Lestrimelitta) rufa Friese, 1903 and Trigona (Lestrimelitta) rufipes Friese, 1903 are designated and redescribed. The male of L. limao (Smith, 1863) is described for the first time. The following additional valid species are diagnosed and their distinctive characters presented: L. ehrhardti Friese, 1931; L. glaberrima Oliveira & Marchi, 2005; L.glabrata Camargo & Moure, 1989; L. monodonta Camargo & Moure, 1989 and L. nana Melo, 2003. Identification keys for workers and males, maps of geographic records and illustrations are presented.

In order to gain more information on the possible use of four gastropod species as metal biomonitors for the Mediterranean area, the influence of body weight upon Cd, Cr, Cu, Pb and Zn concentrations was studied in specimens collected at locations with different degrees of environmental pollution. The selected species were the marine snails Monodonta turbinata Born and Monodonta mutabilis Philippi, and the limpets Patella caerulea L. and Patella lusitanica Gmelin. Significant differences between metal concentrations in individuals from different stations were tested by ANCOVA on log-transformed data with log body weight as covariate. For all species a positive correlation between metal concentrations and body weight was observed, which means that the largest individuals contained the highest levels of metals. The inclusion of body weight as covariate in the statistical analysis explained from 81% to 99% of the metal variability within the organisms and enabled the achievement of improvements in the detection of differences among sites. The four selected species provided a rather univocal picture of bioavailable metal loads at the different stations of the experimental area. Except for Cd, the metal concentrations recorded at the clean stations were found to lie in the range of the lowest values reported in the literature and can be employed as useful background levels which can be referred to for intraspecific comparison within the Mediterranean area. It is concluded that in view of its distribution, unambiguous identification, resistance to pollution and accumulation patterns M. turbinata has considerable potential as a biomonitor of trace metals over the Mediterranean.

Gill marsupia of Cumberlandia monodonta were observed to contain early developmental stages on 27 October 1982. This occurrence, in conjunction with histological examination of gonads from several specimens, documents the first record for autumnal reproductive behavior in C. monodonta, and lends credence to previous speculation that biannual periodicity occurs in this species. Smith (1976, 1978, 1988) systematically examined gametogenesis and reviewed brooding periodicity within the North American Margaritiferidae. However, information concerning margaritiferid reproductive biology remains sparse. Howard (1915) reported a single vernal brooding female of Cumberlandia monodonta (Say, 1829) and briefly described that individual's glochidia (also see Surber, 1915). These data are augmented by the discovery of an autumnal brooding female C. monodonta and histological examination of gonadal tissues from several preserved specimens collected at different localities. MATERIALS AND METHODS Several individuals of Cumberlandia monodonta (obtained from Meramec River, Times Beach access, 3 km east of Eureka, St. Louis County, Missouri, 27 October 1982) were maintained for several days in aquaria. During this period, one individual discharged large quantities of a mucus-like substance from its excurrent siphon. This material was collected immediately and examined microscopically. Forty additional specimens in collections of the University of Massachusetts at Amherst (UMA), Thomas M. Freitag (TMF), and one of the authors (MEG) were available for histological analysis of gonad activity (Table I). Mussels had been preserved either by fixation in 10% formalin, followed by 70% ethanol, or in alcohol without previous fixation. A portion of the viscera of each specimen was embedded in paraffin and sectioned at 8 ,m. Five sections from each specimen were hydrated to water, stained with Ehrlich's hematoxylin and eosin, dehydrated, and mounted. 1 The Tennessee Cooperative Fishery Research Unit is supported jointly by the U.S. Fish and Wildlife Service, Tennessee Wildlife Resources Agency, and Tennessee Technological University. Additional funding was provided by the Center for the Management, Utilization, and Protection of Water Resources, Tennessee Technological University. TRANS. AM. MICROSC. Soc., 109(4): 407-411. 1990. ? Copyright, 1990, by the American Microscopical Society, Inc. This content downloaded from 157.55.39.189 on Fri, 09 Dec 2016 05:30:12 UTC All use subject to http://about.jstor.org/terms TRANS. AM. MICROSC. SOC.

The effects of a nonionic detergent and also of crude oil-detergent mixtures in aqueous solutions were tested by allozyme frequencies at six loci in the Mediterranean marine gastropod Cerithium scabridum Philippi 1849. Our results indicated differential survivorship of allozyme genotypes for both detergent alone and for crude oil-detergent mixtures. This statement is true for all the loci involved in the study. When analyzing each locus separately, two of the six loci (phosphoglucose isomerase and alkaline phosphatase) did not show differential survivorship in detergent pollution. But analyzing the genetic complex involving these two loci we found differential survivorship of specific genotypes. These results reflect the adaptive nature of some PGI genotypes in these marine gastropods and seem inconsistent with the neutral theory of allozyme polymorphisms. Furthermore, these findings suggest that allozyme variants, either singly or in a two-locus structure, demonstrate a differential tolerance to these organic pollutants and can, therefore, be used as detectors of organic pollutants in the sea, as we earlier showed for single loci in two other species of marine gastropods, genus Monodonta (Lavie et al., Environ. Res. 35: 270–276 (1984).

This paper presents a critical assessment of Killingley's approach to the determination of month of collection of marine molluscs by prehistoric people. The basis of the method is careful oxygen isotope measurements made in successive growth increments in the shells. We have analyzed specimens of Monodonta and Patella collected live on the coast of northern Spain, in conjunction with seasonality studies on molluscs from prehistoric sites in the neighborhood. These studies confirm the necessity of making careful analyses of each species under consideration. Given the significance both of interspecies differences and of climatic variability on timescales from a year upwards (particularly important in Killingley's area), we conclude that his apparent accuracy of ± a month is illusory.

Three species of archaeogastropod mollusc, Monodonta lineata (da Costa), Emarginula reticulata Sowerby and Patella vulgata L. were selected as representative members of the Trochacea, Fissurellacea and Patellacea, respectively, for a comparative anatomical and ultrastructural study of the excretory system. Primary urine formation takes place by filtration of blood through the walls of the paired auricles in Monodonta and Emarginula and of the single auricle and ventricle in Patella . Urine then passes to right and left kidneys along the renopericardial canals. Contrary to earlier reports the two kidneys are different in structure and function in all three species, the larger right kidney retaining the primitive function of nitrogenous excretion, the left having a predominantly resorptive role and with a capacity to abstract from the blood solutes of larger molecular mass. The difference in the size of the two kidneys is exaggerated in Patella and Emarginula as a consequence of partial restoration of bilateral symmetry in these limpets. It has been possible to demonstrate at the ultrastructural level that the minute left kidney of Emarginula is functional. The vacuolated epithelial cells of the right kidney contain layered excretory spherules composed of purines, melanin and ferric iron in different proportions in the three genera. There is close similarity in the ultrastructural organization of these cells in Monodonta and Emarginula , but those of Patella show marked differences and their excretory spherules contain a higher proportion of melanin. The position of the left kidney in the mantle skirt, as exemplified by Monodonta , is believed to have arisen in the earliest gastropods correlated with the development of helical coiling. This was accompanied by a change in its blood vessels. It has lost its afferent renal vein, which primitively would have carried deoxygenated blood from the viscera, an arrangement which persists in the right kidney. The left efferent renal vein is reduced in Monodonta and lost in Patella and Emarginula . A new vessel has arisen linking left auricle and left kidney and there is evidence to suggest that it carries post-branchial oxygenated blood. It is believed to serve as both an afferent and major efferent route. The physiological implications of this change in the blood supply are discussed and held to be responsible for the functional differences between the two kidneys, creating conditions in the left which favour resorption of organic solutes and ions, and leaving the right kidney with the primary role of nitrogenous excretion. The evolution of the nephridial gland is examined in this context and is also believed to be correlated with the change in the blood supply to the left kidney. Ultrastructural evidence is given in support of its suggested resorptive function. The significance of the differences between right and left kidneys of archaeogastropods is discussed in relation to the evolution of the monotocardian excretory system, and the possible phylogenetic relationships of the groups of archaeogastropods are considered.

In the digestive glands of gastropod molluscs, metals are metabolized in the sense that they are subject to inorganic biochemical processes within the epithelial cells and lumen of the digestive tubules and the pore cells in the intervening connective tissue. These systems have been examined in the tower shell Cerithium vulgatum Bruguieres, a sediment feeder, the top shell Monodonta articulata Lam., a grazing herbivore, and in the whelk Murex trunculus L., a carnivore whose prey includes Cerithium . These animals were taken from a Mediterranean environment polluted by heavy metals. In all three species the metals are compartmentalized within mineralized granules as phosphates and within lysosomal residual bodies in association with sulphur. However, the extent to which a particular metal is accumulated and the relative proportions that are bound within the different compartments are factors that are primarily determined by the species and not the concentration available in the environment. Thus Cerithium accumulates high concentrations of a wide range of metals from the ingested sediment and these are rendered insoluble and non-toxic in the digestive gland. This unavailability is transferred to Murex when it eats Cerithium because Murex does not accumulate the full range of metals from its prey. Indeed, for some metals there appears to be bioreduction rather than bioamplification. The grazing herbivore Monodonta articulata accumulates a third distinct spectrum of metals. The accumulations in each species do not reflect the levels of all the metals in the environment. The presence of metals in the digestive glands is associated with the removal of magnesium from the phosphate granules but also with an increase in the concentration of magnesium in the tissue. It is proposed that metals induce the formation of magnesium phosphate as a source of metal-binding phosphate ions.

The species Monodonta (Osilinus) articulata Lamark 1822 is recorded as having a shell with mixed minerals: a calcitic microstructural unit is comprised between 2 aragonitic layers.