THE YOUNG NATURALIST. 



165 



MARINE AQUARIUM 

 JOTTINGS. 



By J. Osborne. 



About two years ago you were good 

 enough to publish a brief paper of mine 

 giving a little of my experience with marine 

 aquaria, and I promised at the close that I 

 would, at some future date, give you jottings 

 of my observations on various odds and ends 

 that I had alive at one time or another. 

 You must quite understand that I make no 

 pretence to have any scientific knowledge 

 on the subject, or even to know the scientific 

 names of the various species. It has not 

 been so much study with me as amusement. 

 I followed Natural History in my small way 

 more as a relaxation from the cares of busi- 

 ness than anything else ; nor have I had 

 either time or opportunity for trawling, dred- 

 ging, or using other artificial means for obtain- 

 ing specimens. As said before, my aquarium 

 was but a large propagating glass, without 

 means of artificial aeration other than an 

 ordinary syringe, so that no extraordinary 

 observations could be expected from me. I 

 am making these excuses because, in these 

 days of advancing science such very difficult 

 things have been accomplished, that it seems 

 almost presumptious in me to intrude my 

 humble notes. But they are just the odd 

 jottings of one who took an interest in any- 

 thing he had not seen before, especially if 

 at all outre in appearance, and who endea- 

 voured to keep his eyes open whenever he 

 had the opportunity of taking a stroll on 

 the beach or clambering over the rocks. 



Fish. 



The only fish I ever could keep alive for 

 any length of time were Blennies. These 

 are pretty little fish, and the species I used 

 to get were about two inches long. They 

 frequented rock pools, often small ones, 

 near high-water mark. The water in these 

 pools would become quite tepid in the sun- 



of a hot summer's day, and as the fish could 

 live in them it was easy to understand how 

 they were able to bear the somewhat vitiated 

 water of my aquarium. These would thrive 

 when nothing else would ; and though when 

 first introduced they would hide in the 

 crevices and crannies of the rock- work, they 

 soon became quite familiar, and, as I said 

 in my former paper, would come to the side 

 of the glass at a tap, or would take a morsel 

 of meat from the fingers at the surface of 

 the water. 



I have often found the Gurnet in large 

 pools on the sands, which the tide had left, 

 I never saw them in rock pools. In those 

 places it was easy to drive them to the edge 

 — if a stone was thrown at them they wonld 

 scud right away at full speed, and when 

 they reached the edge their impetus would 

 carry them right out of the water on to the 

 sand where they were easily picked up. I 

 once or twice introduced a very small one into 

 my aquarium, but the limited area did not 

 suit them, nevertheless, I was able to observe 

 one curious habit, which I have also con- 

 firmed by what I have seen in these sand 

 pools. They swim on the very top of the 

 water, with their large eyes above the 

 surface, and any one who examines them 

 will see how well their structure is adapted 

 to this habit, for their eyes are at the highest 

 part of their head, which is considerably 

 enlarged upwards. Doubtless their food is 

 found on the surface, and by their eyes being 

 raised above it, they will see slight motions 

 in smooth waters, and be able to find prey 

 further off than if they needed to see the 

 animal itself. Those who have prepared 

 Gurnets for eating know how large a 

 portion of the fish the head is, and it seems 

 only needed to be so large to elevate the 

 eyes in this way. 



Another large-headed fish, but a very un- 

 interesting one, is locally called the " Bull- 

 head," or oftener the " Polymog." I do not 

 know its scientific name, but is nearly all 



