An online resource based on the award-winning nature guide

Gastropods

Slug Mating Behavior

9-2-13 slugs 035Slugs are hermaphroditic, possessing both male and female organs; most species mate, however, with one slug pursuing the slimy trail of another. If a slug is in mating mode, there is a chemical that is present in its slime that conveys this information to other slugs. When two receptive slugs first encounter each other, there can be extensive interaction prior to mating. The pursuer often mouths the tip of the tail of the slug it’s pursuing (see photograph) to confirm that it’s receptive. The pursued slug may shake its tail vigorously to signal that it’s not interested, in which case they go their separate ways. If the leading slug is receptive, however, mating eventually takes place, with sperm being transferred from each slug to the other through penises that extend half the length of their bodies. During this process, the sexual organs are entwined; occasionally, in some species, the organs get stuck. If this happens, one slug gnaws off the other’s penis in a process called apophallation. The penis is not replaced and the slug lives the rest of its life as a female. (The opening you see on the side of the slug is its respiratory opening, or pneumostome.)

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A Great Christmas Present!

If you’re looking for a present for someone that will be used year round, year after year, Naturally Curious may just fit the bill.  A relative, a friend, your child’s school teacher – it’s the gift that keeps on giving to both young and old!

One reader wrote, “This is a unique book as far as I know. I have several naturalists’ books covering Vermont and the Northeast, and have seen nothing of this breadth, covered to this depth. So much interesting information about birds, amphibians, mammals, insects, plants. This would be useful to those in the mid-Atlantic, New York, and even wider geographic regions. The author gives a month-by-month look at what’s going on in the natural world, and so much of the information would simply be moved forward or back a month in other regions, but would still be relevant because of the wide overlap of species. Very readable. Couldn’t put it down. I consider myself pretty knowledgeable about the natural world, but there was much that was new to me in this book. I would have loved to have this to use as a text when I was teaching. Suitable for a wide range of ages.”

In a recent email to me a parent wrote, “Naturally Curious is our five year old’s unqualified f-a-v-o-r-I-t-e  book. He spends hours regularly returning to it to study it’s vivid pictures and have us read to him about all the different creatures. It is a ‘must have’ for any family with children living in New England…or for anyone that simply shares a love of the outdoors.”

I am a firm believer in fostering a love of nature in young children – the younger the better — but I admit that when I wrote Naturally Curious, I was writing it with adults in mind. It delights me no end to know that children don’t even need a grown-up middleman to enjoy it!


Snail and Slug Eggs

Snails and slugs are very similar, except for a slug’s lack of a shell.  Both are hermaphroditic, possessing male and female reproductive organs.  In some species an individual may behave as a male for a while, then as a female. In a few species, self-fertilization occurs. Some species mate and lay eggs in the spring, some in the fall. Most snails and slugs that hatch in the spring can begin egg laying in the fall. The eggs of both snails and slugs are tiny, white or cream-colored, round and laid in roughly one-inch diameter clusters of 30 or so eggs. Look for these clusters under rotting logs, where they are protected from drying out as well as from freezing.  (Remember to place the log back exactly as you found it.)


How Snails Feed

Most terrestrial snails are herbivorous, feeding on a wide range of vegetation. The snail’s mouth is on the bottom of its head near the shorter pair of tentacles. Snails (and all molluscs) consume their food not with mouthparts, like insects, or teeth, like mammals, but with a rasping tongue or radula. Snails don’t bite their food, but rather, rasp or scrape it. The radula is covered with rows of tiny “toothlets” which rasp particles away from vegetation and move them back towards the snail’s gullet. Different species of snails have differently-shaped toothlets. The radula is used by the snail not only to process food, but to clean bits of dried mucus from its shell. Supposedly if you listen hard, you can actually hear a rasping sound when the latter is occurring. (If you look hard, you can just barely see the orange radula of the land snail in the photograph.)


Naturally Curious wins National Outdoor Book Award

I am delighted to be able to tell you that this morning I learned that NATURALLY CURIOUS won the Nature Guidebook category of the 2011 National Outdoor Book Awards.  I’m honored and humbled by this recognition.   http://www.noba-web.org/books11.htm


Millipede Mystery

This morning I discovered the exoskeletons of nine millipedes clumped together at the top of a rotting stump.  They were covered with slug slime, with said slug still at the scene. Presumably its stomach was full of millipede innards.  If anyone can explain this phenomenon to me, I would be most grateful!


Slug Eggs

If you spend enough time looking under rotting logs, you’re bound to come across the tiny, pearly white eggs of a slug. With the right climate conditions, slugs will mate and lay eggs twice in a summer — once early in the spring, and once in late summer. Thirty to forty days after mating, the female slug lays her eggs under leaves, mulch, or in some other cool and moist location. They will hatch in 10 to 100 days — the length of time slug eggs take to hatch depends upon the temperature – the warmer it is, the faster they hatch.


Eyelash Cup Fungus

Fungi can be divided into two groups – basidiomycetes and ascomycetes.  Basidiomycetes (gilled mushrooms, coral fungus, hedgehog  mushrooms, puffballs, bird’s nest fungus) produce spores on the surface of microscopic cells called basidea.  Ascomycetes (morels, cup fungi, stinkhorns) produce their spores within microscopic sacs (asci).  The slug in this photograph is dining on an ascomycete  — eyelash cup fungus (Scutellinia scutellata), the rim of which bears many stiff, eyelash-like hairs.


Snails and Slugs

Snails and slugs are grouped together as gastropods – a class of Mollusks that includes land, freshwater and sea snails and slugs.  The term “snail” is used for species with an external shell large enough for the soft parts to withdraw completely into it. Those gastropods without a shell, and those with only a very reduced or internal shell, are usually known as “slugs.” We refer to many marine gastropods as seashells, including whelks, conchs, cowries, olives, cone shells, figs and tulips.  While many gastropods are herbivorous grazers, several groups are carnivores, capable of drilling through the skeleton of their prey.


NATURALLY CURIOUS–THE BOOK–WILL BE HERE SOON!

I am delighted to be able to share the good news that you can now pre-order my book, Naturally Curious!  I’ve just seen an advance copy, and the printer did a wonderful job with the photographs, and Trafalgar Square did an equally eye-catching job on the layout – I can truly say I am delighted with the end product of a lifetime of photographing, observing, collecting and researching natural history.  How lucky can one get to have the opportunity to put what one treasures most between the covers of a book?   Naturally Curious will be out October 18th.  If you’re in need of a Christmas present for someone, it might be just the ticket!

I’m offering my blog readers the opportunity to pre-order signed copies of Naturally Curious at a special discount price of $35.00 from my publisher’s web site. This offer is only good until October 15, 2010, at which time the regular retail price of $39.95 will apply. CLICK HERE to take advantage of this special offer!


Slugs -Welcome to a photographic journey through the fields, woods and marshes of New England

Many of the images and much of the information in this blog can be found in my book, Naturally Curious, which is being published this fall.

SLUGS

A slug is basically a snail that lacks or has a greatly reduced (internal) shell. Because of this, slugs tend to dry out quite easily and thus inhabit mostly moist environments, retreating to damp hiding places when the weather is dry. A close look at a slug reveals two pairs of tentacles on its head. The upper pair senses light and the lower pair has the ability to smell things. Both pairs are retractable, and can be regrown if damaged. A slug’s sexual organs (they are hermaphroditic, possessing both male and female parts) are located under the saddle-shaped mantle behind its head. When open, the hole through which respiration takes place is visible on the side of the mantle. In the right light, it is possible to see the layer of mucus, or slime trail, that slugs secrete and on which they travel. This mucus protects the foot of the slug and also contains fibers which prevent the slug from slipping down vertical surfaces. Anyone who has picked up a slug knows that they also coat their own body with slippery mucus, which not only keeps it moist, but helps it elude the grasp of predators.


Land Snails – Welcome to a photographic journey through the fields, woods, and marshes of New England

Many of the images and much of the information in this blog can be found in my book, Naturally Curious, which is being published this fall.

LAND SNAILS

Land snails are gastropods, whose members also include aquatic snails (including marine snails) and slugs. The name gastropod means stomach-foot, which is well-deserved, as members of this group all get about by gliding on a muscular structure on the bottom of the abdomen, called the foot. A close look at a snail reveals two sets of projections, or tentacles, on the front of its head. The two longer ones on top reach up, whereas the two shorter ones beneath them tend to reach down. The top, longer tentacles have light-sensitive organs at their tips, making them the snail's version of eyes, although they only perceive light, not images. The shorter tentacles below them feel, taste and smell the environment in search of food and water and possible predators.


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