#nucella lapillus

[stijlw]

[projetarche]

Arche 1818 — Bigorneau blanc (Nucella lapillus).

Vendredi 13 mars 2020, Raphaël Zacharie de Izarra. _________________________________________ Né le 6 décembre 1965 au Mans, Raphaël Zacharie de Izarra est un écrivain et un vidéaste (bien qu'il n'accepte pas d'être défini en ces termes, « trop forts pour qualifier [ses] petits amusements artistiques »). Depuis 2007, il se met en scène dans plusieurs centaines (milliers ?) de vidéos publiées sur Youtube et Dailymotion. Poète oisif hors du monde et du temps, tout l'inspire et devient prétexte à s'enregistrer (il peut sortir jusqu'à trois vidéos par jour). Obsessionnel, il est l'auteur de très nombreuses chroniques (lectures de ses propres textes, purement littéraires ou politiques), mais aussi d'instants de vie capturés sur le vif (des promenades à vélo, des dégustations de bière, des conversations…), ou d'exercices de style (des montages sur de la musique, plus ou moins étranges…).

Reconnu « adulte handicapé », il dédie chaque seconde de son temps à sa production, et il n'est pas rare de croiser ce personnage lunaire dans les rues du Mans, toujours équipé de son caméscope. En 2014, des associations portent plainte contre lui. Il se retrouve ainsi, par deux fois, devant les juges à devoir s'expliquer sur ses textes polémiques (soumis à passer un examen psychiatrique, on le déclare finalement « pénalement irresponsable »).

Sa chaîne Youtube : https://www.youtube.com/channel/UC4ApXwjJfcTKA3jRWMqgL0A Une tentative de centraliser son œuvre : http://izarralune.blogspot.fr/ _________________________________________ « Projet Arche » : un animal dessiné en quelques minutes chaque jour pendant dix ans. http://projetarche.blogspot.fr

[paeonia-horse]

Dog whelk eggs.

[naturalsciencesbelgium]

Belgian mussels developed stronger shells

Belgian mussels have developed stronger shells over the last hundred years. More calcareous shells protect them better from crabs’ claws and seagulls’ beaks. These predators have increased significantly in number during the last fifty years. ‘Belgian mussels adapt surprisingly well to new environmental conditions’, says biologist Thierry Backeljau (RBINS). ‘They might be more resilient to climate change than we think.’

An international team of biologists analyzed the calcareous structure of mussel shells that were collected along the Belgian coast this last century. You would expect the shells to become thinner because more acidic seawater - due to the increase in CO2 in the atmosphere - breaks down calcareous matter. But the team observed a marked increase in the calcification of mussel shells.

The main causes of the more calcareous mussel shells are changes in predators. The dog whelk (Nucella Lapillus) disappeared at the end of the seventies, after which the number of crabs and seagulls increased during the 1980s and 1990s respectively. This led to a pressure on mussels to develop thicker shells, protecting better against the crabs’ claws and the seagulls’ pecking beaks. According to the scientists, this might mean that our Belgian mussel populations can better cope with future climate changes than previously thought.

A special collection

The researchers evaluated a total of 268 mussels that were collected between 1904 and 2016 on the breakwaters between Nieuwpoort and Ostend. The specimens collected between 1904 and 1987 are part of the collections of the Royal Belgian Institute of Natural sciences (RBINS). This unique collection of one single species is composed of ‘wet’ specimens (shells and body tissue, preserved in ethanol), and ‘dry’ specimens (shells only). They were collected during monitoring programs over the past century. ‘This mussel collection is unique,’ says biologist Thierry Backeljau (RBINS), co-author of the study. ‘It may sound paradoxical, but to have such an extended collection of an animal that is so ubiquitous is rare. Researchers usually focus on exceptional species.’

Dog Whelks and acidification

The dog whelk is an important predator of mussels in the North Sea. Dog whelks make a small hole in the mussel shell, through which they suck the mussel empty. To do this, they must drill through the dark, organic outer layer of the mussel: the periostracum. Mussels with a thicker periostracum are better protected against this type of predator. This created a selective pressure on mussels, favoring a thicker periostracum. The acidification of the North Sea - which breaks down calcareous matter - led to additional pressure in favor of more periostracum, offering better protection to the underlying calcareous layer.

But as of the late 1970s, things changed. The dog whelk population suddenly declined sharply and even died out locally due to the use of tin based paint on ship hulls, particularly tributyltin hydride (TBT). The selection pressure on mussel populations in favor of more periostracum decreased.

Crabs and seagulls

In the meantime, average spring and summer temperatures of North Sea surface waters continued to rise, in line with global ocean trends. The input of minerals and nutrients from the land also increased steadily over the past sixty years due to the discharge of fertilizers and wastewater into rivers (eutrophication). The result: an increase in the amount of algae and thus a greater food supply for all kinds of organisms, including the larvae of decapods such as crabs and lobsters. As a result - helped by overfishing of cod, which feeds on those larvae - the number of crabs and lobsters skyrocketed from the 1980s.

Just like the dog whelk, crabs and lobsters are fond of mussels, which they crush with their claws. Protection by a periostracum makes little difference against this, but a stronger, more calcareous shell does. Moreover, depositing calcium requires less energy than producing a periostracum. Thus, a new selection pressure arose, in favor of more calcareous shells.

This selective pressure was reinforced by the exponential population growth of seagulls in the 1990s, due to the increased number of decapods. The breeding season of seagulls (May and June) coincides with the peak of decapods, which are an important food source for the chicks. But seagulls also eat mussels and increased the selection pressure in favor of a calcareous, solid shell.

Hope for the future?

This study shows that the global effects of climate change, such as ocean acidification, do not simply apply on a local scale. Complex, local changes in ecological conditions can lead to biological outcomes that appear to conflict with predictions on a global scale.

‘The Belgian mussel populations seem able to adapt their shell formation to a wide range of local selection pressures and perturbations’, says Backeljau. ‘This gives hope for the future: mussels may be better armed against climate change than we thought.’ This research also illustrates the importance of natural science collections, such as those of the RBINS, in the study of, and fight against, climate change. ‘Collections and archival specimens help us investigate long-term effects of changes in the environment, which is difficult with experimental studies. It is a powerful research method that, as shown here, can yield surprising results and help us get a clearer picture of historical ecological changes’, concludes Backeljau.

The study was published in Global Change Biology.

[certainplaidpandallama]

Spécificité de la garniture chromosomique

Denise ZICKLER : maître de recherche au C.N.R.S.

CLASSIFICATION

Sciences de la vie

» Génétique

» Biologie moléculaire, génétique moléculaire

Sciences de la vie

» Génétique

» Génétique cellulaire et cytogénétique

Sciences de la vie

» Biologie cellulaire, cytologie

» Structure cellulaire

» Structure cellulaire eucaryote

VOIR AUSSI

ALTERNANCE DE PHASES •

AUTOSOMES •

BARR CORPUSCULE DE ou CORPUSCULE CHROMATINIEN

•

CARYOTYPE • CENTROMÈRE •

CHROMOMÈRE •

CHROMOSOMES HOMOLOGUES •

CHROMOSOMES POLYTÉNIQUES •

DIPLOÏDIE • DOSAGE GÉNIQUE •

FÉCONDATION • GÉNOME •

GONOSOMES ou CHROMOSOMES SEXUELS ou HÉTÉROCHROMOSOMES

•

HAPLOÏDIE •

INACTIVATION DU CHROMOSOME X •

NOMBRE CHROMOSOMIQUE SPÉCIFIQUE

•

NOYAU CELLULAIRE •

GLANDES SALIVAIRES •

DÉTERMINATION DU SEXE • ZYGOTE  Carte mentale

Élargissez votre recherche dans Universalis

Le cycle de reproduction de la plupart des espèces comporte une alternance régulière de deux phases. Durant la

phase haploïde, souvent réduite chez les organismes supérieurs aux seules cellules sexuelles ou gamètes , le noyau contient un lot de chromosomes : par exemple n = 4 chez la drosophile,

n = 13 chez le Coprin, n = 10 chez le maïs, n = 23 chez l'homme. Lors de la

fécondation, quelles que soient les modalités du processus, il y a formation d'une cellule diploïde , ou

zygote, dans laquelle les deux noyaux gamétiques fusionnent, réunissant ainsi dans un seul noyau les n chromosomes venant du gamète femelle et les n

chromosomes provenant du gamète mâle. La cellule diploïde contient donc chaque chromosome, et l' information génétique qu'il porte en double exemplaire (2 n = 8 chez la drosophile signifie 4 paires de chromosomes) et les chromosomes de même type sont appelés chromosomes homologues.

Toutes les cellules des organismes de la même espèce possèdent un nombre chromosomique identique. À cette règle de la constance spécifique il faut cependant apporter quelques réserves, par exemple, les différences chromosomiques entre cellules d'un même organisme (cf. infra : chromosomes polyténiques) et la présence chez plusieurs espèces de petits chromosomes hétérochromatiques ou chromosomes b , dont le nombre varie d'un organisme à l'autre sans modifications du phénotype (ensemble des propriétés observables d'un organisme) de l'individu porteur. Mais généralement le nombre chromosomique d'une espèce donnée est parfaitement constant. Par contre, ce nombre est variable d'une espèce à l'autre, les extrêmes étant n = 1 chez l'ascaris et n supérieur à 300 chez certaines fougères. La taille des chromosomes est elle aussi très variable : les 13 chromosomes du Coprin mis bout à bout ont une longueur inférieure à celle du plus petit des chromosomes humains. Dans un même organisme, on trouve généralement un mélange de petits et de grands chromosomes (de 1 à 8 μm chez l'homme). Des espèces voisines comme les ancolies et les renoncules ont soit de très petits soit de très grands chromosomes. On connaît quelques exemples (rares) de variation du nombre chromosomique d'un individu à l'autre d'une même espèce. Chez le mollusque Nucella lapillus , ce nombre varie de n = 13 à n = 18. La forme 13 possède 5 chromosomes à 2 bras égaux alors que la forme 18 a 10 chromosomes à centromère terminal. Tous ces individus sont interfertiles mais vivent dans des milieux différents. De telles fusions de centromères sont également invoquées dans les évolutions caryotypiques des espèces. La taille et le nombre des chromosomes ne semblent pas corrélés avec la complexité génétique des organismes : une espèce d'ascaris a 2 chromosomes alors qu'une autre espèce d'ascaris en possède 30.

De même, si le contenu en ADN des chromosomes est généralement proportionnel à leur longueur, on trouve des taux très variables parmi les différentes espèces du même genre. Une cellule diploïde humaine contient 5,6 picogrammes d'ADN (1 pg = 1 × 10

g), celle de la drosophile 0,18 pg, celle de l'oignon 55 pg et celle de la salamandre 100 pg. —12

La quantité d'ADN par lot haploïde, ou

valeur c , est tout aussi caractéristique de l'espèce que son nombre chromosomique. Elle pose la même question fondamentale d'organisation du génome que la variation numérique des chromosomes : pourquoi des espèces à évolution comparable ont-elles des taux d'ADN aussi différents ? Un élément de réponse est donné par la comparaison des quantités d'ADN satellite : c = 0,36 pg chez Drosophila virilis et 0,18 pg chez Drosophila melanogaster. Dans la première espèce, l'ADN satellite représente 40 p. 100 de l'ADN nucléaire alors qu'il ne représente que 18 p. 100 dans la seconde. Les masses de séquences uniques sont par contre identiques. Mais la corrélation établie chez ces deux espèces de drosophile entre des valeurs élevées de c et le nombre de séquences d'ADN satellite n'est pas valable pour toutes les espèces.

Aux critères de nombre et de taille des chromosomes définissant l'espèce on peut ajouter trois autres paramètres : la place du centromère, celle des constrictions secondaires et le nombre de bandes. Le centromère peut subdiviser le chromosome en deux bras égaux (métacentrique), en deux bras inégaux (submétacentrique) ou bien être te [...]

[agavex]

Beach finds from May to December 2020, collected between Penzance and Marazion. Objects separated into inorganic and organic arrangements. 

Inorganics: 

4 ceramic fragments

157 pieces of glass, including a marble (though not at all worn it is nonetheless an irresistible shiny thing), and a glass bead which glows under UV light, which is next to the marble, and next to 2 lavender/greys which are some of my favourites here

Organics: 

1 Atlantic surf clam (Spisula solidissima) half

1 rayed trough shell (Mactra stultorum) half

1 banded wedge shell (Donax vittatus) pair

3 blue rayed limpets (Patella pellucida)

42 spotted cowries (Trivia monarcha), which are not as common as this collection might imply, I just make much more effort to look for them because they��re the best thing to find!

5 needle whelks (Bittium reticulatum)

15 pheasant shells (Tricolia pullus)

7 flat periwinkles (Littorina obtustata)

8 netted dog whelks (Tritia reticulata), these are the most abundant species, but I still collect those that are a nice colour, or are particularly well defined, or in this case, unusually tiny

1 Bela nebula shell

1 so far unidentified, very pretty purple, I found one similar in April and thought it might be another flat periwinkle, but with this one the shape is clearly different

1 dog whelk (Nucella lapillus)

2 flat top shell (Steromphala umbilicalis), also an abundant species, and only these were kept for their notably vivid markings

2 rough periwinkles (Littorina saxatilis), one unusually orange, and one unusually small

7 painted top shells (Calliostoma zizyphinum)

[theyoungmarinebiologist20]

Dog Whelk (Nucella lapillus) egg capsules found on a beach in Cornwall, England. Thousands of eggs in each capsule.

[perseidprincess]

I just started reading a paper on “the fine structure and function of the anal glands of Nucella lapillus and Gibbula cineraria.” for my dissertation. I’m studying snail butt holes... when did this become my life and why am I still not turned away from my area of research?

[rbbox]

Cancer pagurus

Cancer pagurus

Cancer pagurus, commonly known as the edible crab or brown crab, is a species of crab found in the North Sea, North Atlantic Ocean and perhaps in the Mediterranean Sea. It is a robust crab of a reddish-brown colour, having an oval carapace with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width of up to 25 cm (10 in) and weigh up to 3 kg (6.6 lb). C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery in Western Europe, centred on the coasts of the British Isles, with more than 60,000 tonnes caught annually. Description Mouthparts and chelae of a female Ventral view of an egg-bearing female The carapace of C. pagurus adults is a reddish-brown colour, while in young specimens it is purple-brown. It occasionally bears white patches, and is shaped along the front edge into nine rounded lobes, resembling a pie crust. Males typically have a carapace 60 millimetres (2.4 in) long, and females 98 mm (4 in) long, although they may reach up to 150 mm (6 in) long in exceptional cases. Carapace width is typically 150 mm (6 in), or exceptionally up to 250 mm (10 in). A fold of the carapace extends ventrally to constitute a branchial chamber where the gills lie. The first pereiopod is modified into a strong cheliped (claw-bearing leg): the claw's fingers, the dactylus and propodus, are black at the tips. The other pereiopods are covered with rows of short stiff setae; the dactylus of each is black towards the tip, and ends in a sharp point. From the front, the antennae and antennules are visible. Beside these there are the orbits in which the eyes are situated. The mouthparts comprise three pairs of maxillipeds, behind which there are a pair of maxillae, a pair of maxillules, and finally the mandibles. In common with most crabs, the abdomen is folded under the thorax and shows clear sexual dimorphism: in males it is comparatively narrow, whereas in the female it is wider. Life cycle Reproduction occurs in winter; the male stands over the female and forms a cage with his legs protecting her while she moults. Internal fertilisation takes place before the hardening of the new carapace, with the aid of two abdominal appendages (gonopods). After mating, the female retreats to a pit on the sea floor to lay her eggs. Between 250,000 and 3,000,000 fertilised eggs are held under the female's abdomen for up to eight months until they hatch. The first developmental stage after hatching is a planktonic larva (1 mm) called the zoea that develops into a postlarva (megalopa), and finally a juvenile. The first juvenile stage is characterised by a well-developed abdomen, which will, in time, become reduced in size and folded under the sternum. Juveniles settle to the sea floor in the intertidal zone, where they stay until they reach a carapace width of 60–70 mm (2.4–2.8 in) and then migrate to deeper water. The growth rate in males slows from an increase in carapace width of 10 mm per year before it is eight years old, to 2 mm per year thereafter. Females grow at about half the rate of males, probably due to the energetic demands of egg laying. Sexual maturity is reached at a carapace width of 12.7 cm (5.0 in) in females, and 11 cm (4.3 in) in males. Longevity is typically 25–30 years, although exceptional individuals may live for up to 100 years. Distribution and ecology The blue mussel, Mytilus edulis, is a favourite food of Cancer pagurus. Cancer pagurus is abundant throughout the northeast Atlantic as far as Norway in the north and northern Africa in the south, on mixed coarse grounds, mud and sand from the shallow sublittoral to depths of about 100 metres (330 ft). It is frequently found inhabiting cracks and holes in rocks but occasionally also in open areas. Smaller specimens may be found under rocks in the littoral zone. Unconfirmed reports suggest that C. pagurus may also occur in the Mediterranean Sea and Black Sea. Adult C. pagurus are nocturnal, hiding buried in the substrate during the day, but foraging at night up to 50 metres (160 ft) from their hideouts. Their diet includes a variety of crustaceans (including the crabs Carcinus maenas and Pilumnus hirtellus, the porcelain crabs Porcellana platycheles and Pisidia longicornis, and the squat lobster Galathea squamifera) and molluscs (including the gastropods Nucella lapillus and Littorina littorea, and the bivalves Ensis, Mytilus edulis, Cerastoderma edule, Ostrea edulis and Lutraria lutraria). It may stalk or ambush motile prey, and may dig large pits to reach buried molluscs. The main predator of Cancer pagurus is the octopus, which will even attack them inside the crab pots that fishermen use to trap them. Compared to other commercially important crab species, relatively little is known about diseases of Cancer pagurus. Its parasites include viruses, such as the white spot syndrome virus, various bacteria that cause dark lesions on the exoskeleton, and Hematodinium-like dinoflagellates that cause "pink crab disease". Other microscopic pathogens include fungi, microsporidians, paramyxeans and ciliates. Cancer pagurus is also targeted by metazoan parasites, including trematodes and parasitic barnacles. A number of sessile animals occasionally settle as epibionts on the exoskeleton of C. pagurus, including barnacles, sea anemones, serpulid polychaetes such as Janua pagenstecheri, bryozoans and saddle oysters. Fishery Crab pots, Lindisfarne, North Sea Cancer pagurus is heavily exploited commercially throughout its range, being the most commercially important crab species in Western Europe. The crabs are caught using crab pots (similar to lobster pots) which are placed offshore and baited. The catch of C. pagurus has increased steadily, rising from 26,000 tonnes in 1978 to 60,000 t in 2007, of which more than 70% was caught around the British Isles. The fishery is widely dispersed around the British and Irish coasts, and C. pagurus is thought to be overfished across much of this area. Most of the edible crabs caught by the British fleet are exported live for sale in France and Spain. A number of legal restrictions apply to the catching of Cancer pagurus. It is illegal to catch "berried" crabs (females carrying eggs), but since ovigerous females remain in pits dug in the sediment and do not feed, fishing pressure does not affect the supply of larvae. Minimum landing sizes (MLS) for C. pagurus are set by both the European Union technical regulations and by the UK government. Different minimum sizes are employed in different geographical areas, to reflect differences in the crab's growth rate across its range. In particular, the "Cromer crab" fishery along the coasts of Suffolk, Norfolk and Lincolnshire is subject to a MLS of 115 mm (4.5 in), rather than the 140 mm (5.5 in) MLS in most of the species' range. An intermediate value of 130 mm (5.1 in) is used in the rest of the North Sea between the 56th parallel north and the Essex–Kent border, and in the Irish Sea south of 55° N. Around Devon, Cornwall and the Isles of Scilly, there is a separate MLS for males (160 mm or 6.3 in) and females (140 mm or 5.5 in). The Norwegian catch is 8,500 tons annually, compared to 20,000 tons in the United Kingdom, 13,000 tons in Ireland, 8,500 tons in France, and a total 45,000 tons globally. Cookery Around one third of the weight of an adult edible crab is meat, of which one third is white meat from the claws (see declawing of crabs), and two thirds is brown meat from the body. As food, male edible crabs are referred to as cocks and females as hens. Cocks have more sweet white meat; hens have more rich brown meat. Dishes include dressed crab (crab meat arranged in the cleaned shell, sometimes with decoration of other foodstuffs), soups such as bisque or bouillabaisse, pâtés, mousses and hot soufflés. Taxonomy and systematics External identifiers for Cancer pagurus Encyclopedia of Life 1022230 ITIS 98681 NCBI 6755 WoRMS 107276 Also found in: Wikispecies According to the rules of the International Code of Zoological Nomenclature, Cancer pagurus was first described by Carl Linnaeus in 1758, in the tenth edition of his Systema Naturae, which marks the starting point of zoological nomenclature. It was chosen to be the type species of the genus Cancer by Pierre André Latreille in 1810. The specific epithet pagurus is a Latin word, deriving from the Ancient Greek πάγουρος (pagouros), which, alongside "κάρκινος" (karkinos), was used to refer to edible marine crabs; neither classical term can be confidently assigned to a particular species. Although the genus Cancer formerly included most crabs, it has since been restricted to eight species. Within that set of closely related species, the closest relative of C. pagurus is the Jonah crab, Cancer borealis, from the east coast of North America. source - Wikipedia Dear friends, if you liked our post, please do not forget to share and comment like this. If you want to share your information with us, please send us your post with your name and photo at RBbox.in@gmail.com. We will publish your post with your name and photo. thanks for joining us www.rbbox.in

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[rashmi-eternities-crafter]

This is a lil late but I got a tattoo on Friday! (!!!)

[agavex]

Beach finds from several walks between Penzance and Marazion during May 2020.

11 ‘mini’ netted dog whelk (Tritia reticulata) shells. I know, I said I’d stop collecting them, but they’re nice, especially the first - bright pink - one in the row. This time I tried arranging the shells by colour instead of size. 

4 needle whelk (Bittium reticulatum) shells. 

5 pheasant shells (Tricolia pullus). 

1 ‘mini’ dog whelk (Nucella lapillus) shell. 

15 spotted cowrie (Trivia monacha) shells. 

48 pieces of sea glass, my favourite this month being the long sky blue one on the bottom row.

5 ceramic fragments: 1 white with a worn edge running through the middle, with two different patterns either side of it, one definitely floral, 1 faded with a waves design, possibly part of willow pattern, 1 more faded but recognisable as willow pattern, 1 almost faded entirely but just recognisable as part of a building, also possibly part of a willow pattern object, and 1 with a dark blue hexagonal pattern that reminds me of chicken wire. 

Not much collected this month, but as the weather heated up (May became the UK’s sunniest month on record) the beaches became busier I’ve been less inclined to go on long walks, plus there’s so much to do in the garden every day that I can no longer take 6 hours out to go to Marazion. I’m still visiting my local beach and combining beachcombing there with collecting seaweed for both composting and making liquid fertilliser, but probably won’t find many things, so unless that changes I’ll combine the finds from the three months of summer into one at the end of August.

[agavex]

Beach finds from several walks between Penzance and Marazion during April 2020.

10 needle whelks (Bittium reticulatum)

7 pheasant shells (Tricolia pullus)

65 ‘mini’ netted dog whelk (Tritia reticulata) shells - I’ll stop collecting these now.

1 ‘mini’ dog whelk (Nucella lapillus) shell.

3 flat periwinkle (Littorina obtusata) shells, 1 tiny purple one, 1 tiny yellow one, and 1 large yellow one. 

3 flat top shells (Gibbula umbilicalis)

3 painted top shells (Calliostoma zizyphinum)

42 spotted cowrie (Trivia monacha) shells - these are my favourite to find so I won’t stop collecting these! However between May and September dogs are banned on the only beach these wash up on, so I won’t be visiting that one much, if at all, over summer. 

2 banded wedge shell (Donax vittatus) pairs

1 common mussel (Mytilus edulis) shell pair

14 ceramic fragments, including 3 grey with parallel lines design, 1 brown with blue glaze, the rest white: 1 with sharp black lines and blue wash; 1 part of a building in blue, probably willow pattern; 1 with unknown objects depicted in dark blue; 1 with dark blue waves; 1 more with willow pattern; 1 with serrated leaf edge and possibly petal in dark grey-blue; 1 possibly leaf or bud - something botanical - in dark blue; 1 depicting several different flowers in mid-blue; 1 tiny plain mid-blue glaze; 1 with leaves in dark green. 

139 glass fragments, including one marble and at last a piece of uranium glass (green, but not with the rest of the greens in the gradient) 

[agavex]

Beach finds from several walks between Penzance and Marazion during March 2020. 

7 pheasant shells (Tricolia pullus)

7 auger shells (Turritella communis) needle whelks (Bittium reticulatum). 

1 dog whelk (Nucella lapillus) shell*

48 netted dog whelk (Tritia reticulata) shells*

25 spotted cowrie (Trivia monacha) shells

1 rayed mactra (Mactra stultorum) shell half

1 pullet carpet shell (Venerupis corrugata) pair (uncertain ID)

1 thin tellin (Tellina tenuis) shell pair

1 flat periwinkle (Littorina obtusata) shell, peachy orange colour

2 flat top shells (Gibbula umbilicalis), as with the previous species, these are very common in this location, but these two have particularly appealing colouration

1 thick top shell (Phorcus lineatus)*

3 painted top shells (Calliostoma zizyphinum)

158 pieces of sea glass, including a marble, what looks like an odd shaped blue glass pebble, and a piece of bicoloured milk glass. 

6 ceramic fragments: white with azure/cyan glaze; 2 willow pattern; 1 dark green design depicting part of a leaf or petal; 1 black design possibly of the veins of a leaf - the shape of the fragment makes it seem that way; 1 sepia, depicting either stylised foliage, waves or wind. 

* = collected because of miniature (immature) size. The rest of the shell specimens are average adult size.

[agavex]

Beach finds from between Penzance and Marazion. 9 January 2020.

4 bivalve shell pairs that are probably all pullet carpet shells (Venerupis corrugata), even the one furthest right which is more difficult to identify as any markings have been worn away. 

1 dog whelk (Nucella lapillus) with more prominent grooves than most. 

4 ceramic fragments:

1 perfectly weathered piece with cracked glaze and part of an abstract or maybe botanical pattern in dark green. 

1 small edge piece, the small amount of blue design that’s visible looks like ripples on calm water. 

1 edge piece with leaves and stem design in black. 

1 edge piece which could be part of a willow pattern plate, with part of a tree or cloud just visible. 

77 glass fragments, including part of a stopper which isn’t weathered to the standard I usually collect but any evidence of glass stoppers to me is worth keeping. Favourite piece this week is easy: the long(ish) cornflower blue one upper middle. The large grey one and lavender ones to the right of that are very nice too.

[agavex]

Beach finds from between Penzance and Marazion. 23 January 2020.

common cockle (Cerastoderma edule) shell half, about a third of the size of the average adult shell.

flat periwinkle (Littorina obtusata) shell, another white one, much larger this time. 

3 netted dog whelk (Tritia reticulata) shells, half size or smaller than the average adult, the one on the right only 7mm long. 

3 snails of uncertain ID, either young dog whelks (Nucella lapillus), or the same species found in St Ives last month (possibly Lacuna crassior).

another snail of uncertain ID, so far I’m guessing it’s a very young turban top shell (Gibbula magus).

3 European, or spotted cowrie (Trivia monacha) shells. 

tube of cemented sand grains and shell fragments created by the sand mason worm (Lanice conchilega).

3 ceramic fragments: 1 of the usual warm grey with cool grey lines material; 1 similar, but with lines closer together; and 1 blue, rounded, possibly the edge of a container.

57 glass fragments, including a huge yellowy-clear piece, another stopper fragment, and half of a bottleneck with the thread inside still faintly visible. 

[agavex]

Beach finds from St Ives, Cornwall. 13 December 2019.

Another stopper, this time a vulcanite one. It’s well worn but I can just make out a few concentric rings which is a match to what the St Austell Brewery used from the 1930s onwards.

A brush without bristles.

15 ceramics: 2 more of those cool grey lines on warm grey material pieces which are common around Penzance too; 3 pieces of white with a thick dark green glaze which sparkles where tiny pieces of the matt surface have been chipped away; cool dark brown on lighter warm brown, glazed on both sides; lighter warm brown on even lighter warm brown, also glazed on both sides; cream partly glazed with red in a scaly pattern; darker cream with white and maroon sun-like design; white with maroon part of a flower; white with cream glaze and delicate black feather or leaf design in black; beige, with shiny glaze and design painted around the form of the ceramic, so it’s like a 3D effect (it’s flat on the other side); white and blue willow pattern; white and plain sky blue; and white and blue willow pattern again – tiny!

25 glass: all common colours except for one lilac/lavender piece.

2… parts of crustacean exoskeleton? I’m still figuring this out.

5 shells with uncertain ID. Closest match seems to be Lacuna crassior.

1 pullet carpet shell (Venerupis corrugata) shell pair.

1 netted dog whelk (Tritia reticulata), the best condition of this species I’ve found so far.

1 flat top shell (Gibbula umbilicalis) with especially pretty markings.

1 blue-rayed limpet (Patella pellucida), a way better example of this species than the last one I found – the rays are visible!

16 dog whelks (Nucella lapillus), a wide range of sizes and colours.