Glimpses of Ocean Life 17

Glimpses of Ocean Life 17

1 COMMON BARNACLES attached to shell of Limpet

2 ANIMAL OF THE LIMPET (_P. vulgata_) as seen from below

3 THE LAMINATED NEREIS (_Phyllodoce Laminosa_)]

 

 

 

 

IX.

 

 

To oblige an English correspondent who requested some blocks of

stone containing Pholas perforations, the writer, in company with a

fellow-student, started betimes for the sea-shore, some four miles'

distance. We made for a certain spot, where it was expected the object

of our wishes could easily be found. Our equipment consisted merely

of a hammer, a bottle, and two chisels, enclosed in a carpet-bag, the

better to mask our mission from impertinent curiosity.

 

On reaching the shore, it soon became painfully apparent that no pieces

of rock could be procured of a character at all suitable for a museum.

To make matters still more irritating, a breeze arose, and with it

came a furious shower of rain, which soon completely saturated our

light costume. At such a time it is laughable to note how faint becomes

the poetry of practical zoology--how excessively like street puddles

are the fairy-grots, as the rock-pools are called; how unsightly the

great, distorted anemones look, too, when viewed from beneath a large

boulder, where you are crouched in the fond idea that you are thus

getting shelter from the rain.

 

On this occasion, my friend and I, being soaked to the skin, started

up from our unpleasant position, and boldly daring the rain to do its

worst, proceeded to hunt after any object of interest that might by

chance be lying stranded near.

 

After an hour's search, two objects, among many others of more or less

interest, were captured, that fully repaid us for our uncomfortable

'ducking.' The first was an elegant Actinia (_A. Dianthus_), which

seemed to be exquisitely modelled in the finest virgin wax. The second

was a specimen of the Laminated Nereis (_Phyllodoce Laminosa_), a

wonderfully beautiful _worm_!

 

Fair reader, start not nor curl that rosy lip of thine at the

__EXPRESSION__, 'beautiful,' being applied to such an humble creature, for

indeed the title is a just and true one.

 

This Annelid is generally found coiled up and attached to the under

part of stones situated near low water mark. Its general colour is

emerald green, excepting along the centre of the back, which is

iridescent, and reflects a brilliant blue, changing into purple and

other hues, only equalled in beauty by the enamelled corslet of the

brightest beetle, or the flashing tints that dance upon the plumage of

the humming-bird.

 

The body of the _P. Laminosa_, like that of all other _Dorsibranchiate

Annelidans_, is divided into a consecutive series of rings. Upon either

side of each ring is situated a singular appendage, which acts as a

gill or branchial organ, by the exercise of which the blood of the

animal is effectually purified, and respiration adequately provided for.

 

When the Nereis is in a state of repose, these gills are laid flat over

its back; but in a state of activity they are fully spread out, and act

as 'paddles,' by aid of which the animal is enabled to glide through

its native element with a graceful serpentine motion.

 

At the base of each paddle is situated a smaller one, consisting of

a fleshy pedicle shielding a fan-like bunch of hairs, each of which

tapers to a sharp point. Combined, these hairs or spines form a

powerful defensive weapon, which can be extended or retracted at will;

and it also serves as an _oar_, or propeller.

 

As a noteworthy instance of tenacity of life in the lower animals, it

may be well to mention here that I have on various occasions, by aid of

the microscope, watched for several minutes the bunch of spines, above

alluded to, thrust out and retracted in a single segment cut from the

body of the Nereis; and only as the object became devoid of moisture

did its beautiful mechanism cease to play.

 

The specimen now before me is comparatively small, being only twelve

inches in length, yet its body contains nearly one thousand lateral

appendages, constituting, it must be admitted, a most extensive and

wonderful locomotive apparatus.

 

This Annelid is not a suitable object for the aquarium, on account of

its frequent great length, and the consequent likelihood of its getting

entangled among stones and rock-work when in search of food.

 

If the hinder parts be cut off, as has been already hinted, they will

exhibit vitality for a considerable period when placed in water, but

we are told it is the anterior (?) portion of the Phyllodoce which

alone possesses the power of regenerating lost segments; these will be

reproduced sometimes at the rate of three or four in a week.

 

'These creatures,' says a learned author, 'as might be expected from

their activity and erratic habits, are carnivorous; and innocent and

beautiful as they look, they are furnished with weapons of destruction

of a unique and most curious description. The mouth of the Nereis would

seem at first to be a simple opening, quite destitute of teeth; but on

further examination, this aperture is found to lead into a capacious

bag, the walls of which are provided with sharp, horny plates, even

more terrible than those which are occasionally to be met with in

the gizzards of some of the higher animals. It is not surprising,

therefore, that by many anatomists the structure in question has been

described as a real gizzard, or by some as the stomach itself. A little

attention to the habits of the living Annelid will, however, soon

reveal the true character of the organ. No sooner does the creature

wish to seize its food than this so-called gizzard is at once turned

inside out, in which condition it protrudes from the mouth like a great

proboscis, and the teeth, which were before concealed in the interior

of the cavity, now become external, and display as formidable an

assortment of rasps, files, knives, saws, hooks, or crooked fangs, as

any one could wish to see. Let us suppose them, when in this condition,

plunged into the body of some poor helpless victim, while at the same

moment the proboscis is rapidly inverted and withdrawn; the prey thus

seized is at the same instant swallowed, and at once plunged into a

gulf where all struggles are unavailing, there to be bruised, and

crushed, and sucked at leisure.'

 

There is a curious fact in connection with these Annelids which is

too interesting to be omitted here. I allude to the wonderful manner

in which their young are produced by a process that may be called

'sprouting.'

 

This invariably takes place in the segment immediately preceding

the terminal one. When a new animal is about to be formed, the

reproductive segment swells, and after a certain time the infant

worm is seen growing from the tail of its parent. When sufficiently

developed, the offspring detaches itself, and starts life on its own

account. Sometimes before the elder born Annelid is fully formed, the

mysterious segment produces a second offspring, and, according to

Professor Milne Edwards, as many as six young ones may be generated in

succession from the same posterior segment, all of which will for some

time continue attached to the parent worm.

 

 

 

 

CHAPTER X.

 

The Fan-Amphitrite.

 

 

 

 

X.

 

 

At the lowest ebb of spring-tide may often be seen protruding above

the surface of the beach an object that at a little distance might be

mistaken for the twig of a tree, or a decayed and blackened reed. A

close examination discloses it to be a smooth, tough tube, apparently

composed of dark leather or old gutta-percha, affixed at its lower

extremity to some rock or other solid substance.

 

The pretty Annelid occupying this dark cylinder is the Fan-Amphitrite

(_A. ventilabrum_). Unlike the Terrebella, this animal may really be

captured without much difficulty. The first time I made the experiment

it was successful. By carefully digging down with chisel, or digits,

to the base of the tube, which may be reached in the course of a

few minutes, the entire structure, with its living occupant, may be

transferred to your extemporaneous tank.

 

I have an Amphitrite in my aquarium at the present time displaying its

richly-tinted tentacula to the sun, which lights them up with unusual

beauty.

 

As the 'case' of this animal is flexible, and as its owner will only

thrive in an upright position, the reader will easily conceive that

to afford the Annelid suitable accommodation in the aquarium is not

a very easy task. What other naturalists do I cannot tell; but the

following is the plan I adopt for the creature's comfort and my own

gratification:--

 

Having procured a small cylinder of glass (or gutta-percha), close up

one end, and drop in the Amphitrite, taking care to first tie the lower

portion of its sheath with a piece of thread or silk. It is very pretty

to see the plume of the Annelid spreading completely over and covering

the extremity of the tube, giving the idea in the one instance that the

animal was mysteriously gifted with the power of exuding gutta-percha

instead of its usual mucus.

 

The Annelid may be made to recline against the sides of the vase, or be

propped up on any chosen spot by aid of a small cairn of pebbles, and

thus form a very curious feature in the aquarium.

 

To test a fact, relative to the power which the Amphitrite is said

to possess, in common with other tubiculous Annelids, of renewing

certain portions of its body after sustaining injury, I snipped off the

principal portions of its branchiæ, and found that, after the lapse of

a few months, my specimen renewed its mutilated organs.