'&110t:-r e4-44Wre FISHERIES AND MARINE SERVICE -eLY

Translation Series No. 3604

The role of the squamattis (L.) in the biology of anisakids

by E.D. Valter and T.I. Popova

Original title: 0 roli polikhety Lepidonotus squamatus (L.) v biologii anisakid

From: Tr. Belomorsk. Biol. Stn. Mosk. Gos. Univ. 4: 177-182 1974

Translated by L. Margolis Department of the Environment Fisheries and Marine Service Pacific Biological Station Nanaimo, B.C.

1975 6 pages typescript it 277 3L,,oLé

Polychaetes are important components of the food of many of fishes (Vinogradov, 1948; Pertsov, 1952; Timakova, 1957; and others) and therefore can serve as connecting links in the life cycles of helminths. The significant role of as intermediate hosts of helminths of vertebrates was shown in the work of Margolis (1971) who reviewed all available published information on this question.

While studying the life cycle of Contracaecum aduncum (Rudolphi, 1802) we determined the existence of significant infections of this nematode in many White Sea polychaetes (Popova and Valter, 1967; Valter, 1970a).

Of the aphroditids in the region of the White Sea Station of MGU [Moscow State University], where our studies were carried out, the most abundant species is Lepidonotus squamatus (L.).

During the period from 1962 to 1967 we examined 1192 specimens of Lepidonotus which were found to be highly infected (11.3%) with larvae of C. aduncum. Besides these larvae, larvae of two other Ascaridata (Terranova decipiens (Krabbe, 1878) and Anisakis sp.) were found, however with a lower • prevalence of infection (0.087e). During identification of the larvae we studied the structure of their digestive tract, i.e. the presence or absence of appendices, and also the structure of the head and tail ends and the position of the excretory pore.

The parasites were localized most frequently in the body cavity of the polychaetes. Sometimes larvae of C. aduncum penetrated into the musculature of the parapodia, the head end becoming embedded, with the rest of the body freely protruding into the body cavity of the . The phenomenon of crawling into narrow openings is very characteristic for nematodes (Skrjabin and Shults, 1931; Andreev, 1967).

A special paper (Valter, 1970b) has been devoted to the morphological characteristics of C. aduncum larvae extracted from polychaetes.

In the present report we turn our attention to the larvae of Anisakis sp. and T. decipiens.

Before assessing the role of L. squamatus in the life cycle of the above anisakids, it is necessary, even if only conjecturally, to ascertain to which life stage they belong. Since this is not possible without morphological 'descriptions, we give descriptions of these larvae below.

Anisakis sp. (fig. 1). Length of body 4.543 mm. Maximal width of body 0.224 mm. Width of body in region of the head end 0.067 mm, width at level of ventriculus 0.196 mm, width of body in region of anus 0.140 mm. On the cuticle fine transverse striations are visible. Head end of larvae bears a rather large larval boring tooth, as is characteristic for Many Ascaridata. Nerve ring located at a distance of 0.196 mm from anterior end of body. Length of esophagus 0.588 mm with width 0.063 mm. Characteristic of the larva is a large ventriculus having the shape of an elongated rectangle: Length of the ventriculus 0.266 mm, width 0.133 mm. Immediately following the ventriculus, the digestive tract narrows, reaching a maximum width in the middle part of the body. Then it narrows again, ending near the posterior epd of the body in the - 2 -- anal opening located at a distance of 0.126 mm from the tip of the tail. Anal glands characteristic of the genus Anisakis are present. Tail end of the larva pointed and somewhat curved on the ventral side.

The location of the excretory pore at the anterior end is characteristic of representatives of the genus Anisakis (Mozgovoy, 1953). This feature is clearly expressed in the larva we found. The excretory pore lies a little below the boring tooth at a distance of 0.018 mm from the anterior-most margin of the head.

Terranova decipiens (fig. 2). Length of larva 3.724 mm. Body tapers at both ends. Anterior end of body bluntly rounded, posterior end pointed'. Maximal width of body 0.182 mm. Width of body in region of head end 0.070 mm, width of body at level of ventriculus 0.175 mm, width . of body in region of anus 0.112 Mm. Cuticle bears fine transverse striations. As in the larva of Anisakis sp., this larva bears a boring tooth on the head end. During examination under high magnification of the microscope it can be seen that the surface of the tooth is uneven. Under the cuticle of the head end are conspicuous papillae, characteristic of subsequent stages in the life of the nematode. Excretory pore highly visible and leading into a narrow canal. It is located at a distance of 0.027 mm from the anterior margin of the head, a little below the tooth. Nerve ring located at a distance of 0.189 mm from anterior end of body. The digestive system of the larva is distinguished by a unique form. Above all this concerns the presence of an intestinal caecum. It is clearly expressed and has a length of 0.114 mm and a width of 0.030 mm. Esophagus 0.532 mm in length and 0.056 mm in width. Ventriculus 0.245 mm in length with width 0.112 mm. Anal opening is found at'a distance of 0.087 mm from the tip of the tail. Anal glands present.

On the basis of their morphological characters one can judge the stage of development of these larvae.

Larvae of both species have a rather large size - 4.5 mm (Anisakis sp.) and 3.7 mm (T. decipiens). In the larvae their is a well-developed boring tooth, a fully formed digestive system, and an elongated and pointed tail end. It is possible to state with confidence that these larvae are third stage. We did not once find larvae similar in size and structure in fishes (cod, navaga, shorthorn sculpins), which they enter with intermediate hosts.

Fishes infected with anisakids feed on different benthic , including polychaetes. In examining fish we frequently found in the food boli their setae • and elytra of Lepidonotus. According to data in the literature it is known that various crustaceans can fulfill the role of the first intermediate host of Anisakis sp. and T. decipiens (Scott and Black, 1960; Uspenskaya, 1963; and others). In 1964 T. I. Popova, A. A. Mozgovoy and M. A. Dmitrenko conjectured that among the intermediate hosts of T. decipiens are "some representatives of polychaete worms." Our findings indicate the definite possibility of the participation of the polychaete L. squamatus in the life cycle of the above-mentioned anisakids and confirm the supposition of Popova, Mozgovoy, and Dmitrenko.

However a small percent (0.087,) of Lepidonotus infected with larvae of these Ascaridata compels us to think that the obligatory intermediate hosts of these nematodes are some other invertebrates, possibly crustaceans. 3 MM.

The high prevalence of infection of L. squamatus with larvae of C. aduncum (11.3%) allows us to consider this polychaete as an obligatory intermediate host of C. aduncum.

' Our finding of larvae of Anisakis sp. and T. decipiens in L. squamatus increases our knowledge about the biology of these species of anisakids. Lepidonotus squamatus, thus, is recorded for the first time as an intermediate host of Anisakis sp. and T. decipiens.

Literature

Andreev H.A. [The importance of mechanical factors and feeding in the nematodes Ascaris suum and Ascaridia galli.] "Mat-ly k Nauchn. Konf. Vses. 0-Va Gelmintologov", Pt. 5. Moscow, 1967.

Valter E.D. [Infection of White Sea fish and polychaetes with Contracaecum aduncum (Rud., 1802) Baylis, 1920d In: [Biology of the White Sea, vol. 3.] Izd-vo MGU, 1970a.

Valter E.D. [Morphological studies on larvae of Contracaecum aduncuml. In: [Biology of the White Sea, vol. 3.1 Izd-vo MGU, 1970b.

Vinogradov K.A. [On the question of the use of polychaetes as food for fish.] DAN SSSR, 1948, v. 60, no. 7.

Mozgovoy A.A. [Ascaridata of and man and the diseasescaused by them.] Principles of nematodology, vol. 2, book 2. Moscow, Izd-vo AN SSSR, 1953.

Pertsov N.A. [Common invertebrates of the White Sea littoral zone as components of the food of fish and birds and methods for determining their mean size and weight.] "Tr. Vses. Gidrobiol. 0-va", 4. Moscow, Izd-vo AN SSSR, 1952.

Popova T.I. and Valter E.D. [Infection of White Sea polychaetes with larvae of Ascaridata.] "Tez. Dokl. V Konf. Parazitologov USSR". Kiev, 1967.

Popova T.I., Mozgovoy A.A., and Dmitrenko M.A. [On the study of the biology of Ascaridata of animais of the White Sea.] "Tr. GELAN", vol. 14. Moscow, "Nauka", 1964.

Skrjabin, K.I. and Shults R.S. [Helminthoses of man. Principles of medical helminthology, pt. 2.] Moscow-Leningrad, 1931.

Timakova M.N. [Feeding and food interrelationships of navaga and smelts of Navaga Bay in the White Sea.1 "Mat-ly po Kompleksh. Izucheniyu Belogo Morya", no. 1. Moscow-Leningrad, Izd-vo AN SSSR, 1957.

Uspenskaya A.V. [Parasite fauna of benthic crustaceans in the Barents Sea.] Moscow-Leningrad, Izd-vo AN SSSR, 1963. 4

Margolis L. Parasites as intermediate hosts of helminth parasites of vertebrates: A review. "J. Fish. Res. Bd. Canada", 1971, v. 28, no. 10.

Scott D.M. and Black W.F. Studies on the life-history of the ascarid Porrocaecum decipiens in the Bras d'Or Lakes, Nova Scotia, Canada. "J. Fish. Res. Bd. Canada", 1960, v. 17, no. 6. 5

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Fig. 1. Larva of Anisakis sp. a - anterior end of body; b - head end; B - posterior end • -6

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Fig. 2. Larva of Terranova decipiens a - anterior end of body; b - head end; B - tail end