Accessory Sacs Research Articles

Functional Morphology of the Olfactory Organ inSpinachia spinachia(L.) (Teleostei, Gasterosteidae)

The functional morphology of the olfactory organ in Spinachia spinachia (L.), which has only a single nare, was studied by light microscopy, scanning electron microscopy, and experimental investigations. It was shown that only the incoming water passes over the olfactory epithelium. The device for ventilating this olfactory organ is an accessory ventilation sac activated by respiratory pressure changes in the buccal cavity. This one-way water current over the olfactory epithelium in a monotrematous olfactory organ was found to be possible because of the morphology of the olfactory organ combined with movements of the lateral wall of the olfactory organ and the nasal tube during respiration. The olfactory epithelium is divided into irregular islets. Both ciliated receptor cells and microvillous receptor cells are present.

Structure and function of the olfactory apparatus in the fresh-water carp, Labeo rohita ham. buch.

The oval olfactory rosette of the carp Labeo rohita belongs to Burne's ('09) rosette column one or to Bateson's (1889) rosette type three. The total olfactory area of the fish is greater than its total retinal area; however, it has been classified with Teichmann's ('54) group of eye-nose fishes. Each olfactory chamber communicates with an anterior, ventral accessory sac; in spite of Burne's ('09) observation that accessory sacs are absent in carps. Movements of the jaw bones dilate and compress the accessory sac. Water is drawn in through the posterior opening (and not through the anterior as suggested by Liermann, '33, and Johnson and Brown, '62) and also expelled through it when the mouth opens and closes for normal respiratory function. Hence, the accessory sac does not draw water across the olfactory rosette through the anterior opening. At intervals, the fish opens its mouth full and wide and draws water into the chamber through the anterior opening as well.

A study of the anatomy ofPupaandMaxacteon(Acteonidae, Opisthobranchia), with an account of the breeding cycle ofPupa kirki

Summary The external features, mantle cavity, reproductive system and nervous system of Pupa kirki (Hutton, 1873) and three species of Maxacteon Rudman, 1971 are described and compared with Acteon tornatilis (L). It is suggested that the reproductive system of Pupa and Maxacteon, with two accessory sacs, the gametolytic sac and an exogenous sperm sac, is more primitive than that of Acteon tornatilis. The breeding cycle of Pupa kirki shows that the species has a basic annual cycle, a few specimens surviving for two years.

Das Geruchsorgan des TiefseefischesAphanopus carbo (Percomorphi, Trichiuridae)

The paper deals with the structure of the olfactory organ, its accessory parts and the forebrain in the deep-sea fishAphanopus carbo. On each side of the head only one opening leads to the olfactory chamber. The olfactory folds are arranged in a rosette-like pattern, resembling the 360°-type. Secondary folds on the main folds may serve as an enlargement of the surface of the olfactory epithelium. Most of the surface area of the olfactory folds is covered by the olfactory epithelium, indicating that the receptive area is of optimal extension. The histological structure of the olfactory epithelium is similar to that in other teleost species. The number of olfactory receptors amounts to about 5×106 to 107 for the single organ. Numerous secretory cells of unknown function are located within the olfactory epithelium. The olfactory chamber is enlarged by three accessory sacs: Two ethmoidal sacs and one lacrymal sac (consisting of two parts). These sacs serve as ventilation aparatus which causes a permanent water current within the olfactory chamber and between the olfactory folds. The action of the accessory sacs is induced by the splanchnokinetic. The forebrain ofAphanopus carbo is well developed; its size ranges between that of forebrains in microsmatic and macrosmatic teleost species. A detailed investigation of the forebrain is in preparation. The diagnosis of the different parts of the olfactory apparatus ofAphanopus carbo demonstrates clearly that — in addition to the eye — this sense organ is well developed (relative to that in other teleosts). This fact suggests thatAphanopus carbo is related to a group of teleost species characterized by optical and olfactory orientation mechanisms of high performance.

Hymenolepis (Hym.) deblocki sp. n., and records of other helminths from charadriiform birds.

Records are presented of 18 species of cestodes and trematodes collected from shorebirds near Bristol Bay, Alaska, in 1960. Hymenolepis (Hym.) deblocki sp. n. is described from Limnodromus griseus (Gmelin). It differs from all other species in the genus in possessing an unarmed accessory sac, unarmed suckers, vagina swollen and armed, and cirrus with stylet.