Image #1. Collecting guns and transport gear. Legend below.
These mini-guns and associated transport gear were made several years ago after finding the collection of the nudibranch-attached gobies were more difficult to collect than I had originally anticipated.
Information on the images:
1-A: The Mares Snub-nose pneumatic spear gun w/ stainless steel prongs on the shaft end. The use of this gun is probably "overkill", as this small, but relatively powerful gun tends to damage or kill the gobies, and frequently knocks the nudi off the goby's body. Its primary advantage is that its use allows some of the more "skittish" gobies to be collected from a greater distance than that required with the mini-guns. This gun is of course independent of the others, which are carried together as a single unit.
1-B: Plastic tube to carry the mini-spear guns underwater. The tube (30mm dia.) is a shortened golf bag liner, used by golfers to separate the individual golf clubs within a golf bag. Soft plastic medicine bottle lids serve to keep the mini-guns & spear shafts w/I the tube until needed. There is a lead fishing weight (RH end of the tube) beneath the white plastic tape, used to prevent the empty tube from floating away once the mini-guns have been removed. Incidentally, the tube is used to concentrate the two guns and spear shafts into a single easily carried unit underwater, as well as to keep the collector from stabbing himself with the sharp tips or entangling the mini-guns on miscellaneous dive paraphernalia.
1-C: The primary mini-gun. The tube is made of 9mm OD titanium tubing (the titanium isn't necessary, but it's what I had on hand at the time) with small plastic center-drilled vial caps on both ends, used as guides for the 2mm X 45mm spear shaft. A short length of thin diameter rubber tubing is held in place via the black plastic electrical tie. A 4cm length of 1cm dia. "shrink-wrap" electrical material is used as the contact point for the spear shaft and tubing (a 3cm length of "shrink-wrap" for the secondary mini-gun below).The device is used much the same as a Hawaiian Sling, as favored by some U/W spear fishermen.
1-D: The secondary mini-gun. Also w/ a titanium tube, but smaller diameter (6mm OD) than that of the above primary mini-gun. The smaller diameter makes the use of the plastic vial caps as guides, unnecessary.
1-C & 1-D: The two mini-guns and their stainless steel rod spears. The spear tips are of two types: 1). With 11 fishhooks, held in place w/ stainless steel wire and then a liberal amount of epoxy used to permanently hold the hooks to the end of the shaft. This tip of course damages the specimens, and 2). This tip is made up of a series of stainless steel wires, sharpened to a point, and bound with stainless steel wire and epoxy. This spear tip works the best; when hit with this spear tip, the gobies are frequently loosely wedged between the tines of the spear tip and can be removed to a collecting bag w/o undue damage to either the goby or nudibranch.
Image #2. A view of the two mini-guns and the inclosed spear shafts.
Image #3. Detail of the attached surgical tubing to the primary mini-gun.
Image #4. Detail of a spear tip made with stainless steel wire.
Image #5. Detail of a spear tip made with stainless steel fishhooks.