New species and new records of camallanid nematodes (Nematoda, Camallanidae) from marine fishes and sea snakes in New Caledonia

Recent examinations of camallanid nematodes (Camallanidae) from marine fishes off New Caledonia, collected in the years 2003–2011, revealed the presence of the following five new species of Procamallanus Baylis, 1923, all belonging to the subgenus Spirocamallanus Olsen, 1952: Procamallanus (Spirocamallanus) dispar n. sp. from the common ponyfish Leiognathus equulus (type host) and the striped ponyfish Aurigequula fasciata (both Leiognathidae, Perciformes); Procamallanus (Spirocamallanus) bothi n. sp. from the leopard flounder Bothus pantherinus (Bothidae, Pleuronectiformes); Procamallanus (Spirocamallanus) hexophtalmatis n. sp. from the speckled sandperch Parapercis hexophtalma (Pinguipedidae, Perciformes); Procamallanus (Spirocamallanus) synodi n. sp. from the sand lizardfish Synodus dermatogenys (Synodontidae, Aulopiformes); and Procamallanus (Spirocamallanus) thalassomatis n. sp. from the yellow-brown wrasse Thalassoma lutescens (Labridae, Perciformes). These are described based on light and scanning electron microscopical (SEM) studies. An additional three congeneric nematodes unidentifiable to species are reported from perciform fishes and a shark: Procamallanus (Spirocamallanus) sp. 3 of Moravec et al., 2006, Procamallanus (Spirocamallanus) sp. 1, and Procamallanus (Spirocamallanus) sp. 2. Ten fish species are recorded as new hosts for Camallanus carangis Olsen, 1954. Two camallanids, Procamallanus (Spirocamallanus) sp. 3 (subgravid female) and Camallanus carangis (fourth-stage larva) were also found in the digestive tract of the New Caledonian sea krait Laticauda saintgironsi, serving apparently as postcyclic and paratenic hosts, respectively, for these fish nematodes.


Introduction
Nematodes of the family Camallanidae Railliet et Henry, 1915, characterized by a well-developed, usually orangecoloured buccal capsule and a life cycle involving a copepod intermediate host, are mostly gastrointestinal, blood-sucking parasites of marine, brackish-water and freshwater fishes and, less often, of amphibians and aquatic reptiles (turtles, snakes) [1,10,41]. Although camallanids are frequent parasites of Indo-Pacific fishes, where many species have been reported, data on these nematodes in New Caledonian waters are scarce. To date, only the following nominal species of camallanids have been recorded from New Caledonia: Camallanus cotti

Materials and methods
Fish were caught off New Caledonia by various means; those obtained from the fishmarket in Nouméa were very fresh and thus were probably fished in the near vicinity. For fish, we generally used the "wash" method [15]. For sea snakes, as these hosts are emblematic protected species, an indirect sampling method without any effect on the individual survival was used; a gentle massage of the sea krait abdomen provided the stomach content by regurgitation [4]. The regurgitated contents might include recently swallowed fish, which are thus recognizable [43], or, if digestion has already occurred, no recognizable item, as was the case for the samples described in this study. The nematodes for morphological studies were fixed in hot 4% formalin or 70% ethanol. For light microscopical examination, they were cleared with glycerine. Drawings were made with the aid of a Zeiss microscope drawing attachment. Specimens used for scanning electron microscopical (SEM) examination were postfixed in 1% osmium tetroxide (in phosphate buffer), dehydrated through a graded acetone series, criticalpoint-dried and sputter-coated with gold; they were examined using a JEOL JSM-7401F scanning electron microscope at an accelerating voltage of 4 kV (GB low mode). All measurements are in micrometres unless otherwise indicated. The fish nomenclature adopted follows FishBase [7].

Remarks
The present specimens from L. equulus and A. fasciata are considered to be conspecific because of their morphological and biometrical similarity and the fact that both of their host species belong to the same fish family. These nematodes belong to the subgenus Spirocamallanus of the genus Procamallanus in the conception of Moravec and Thatcher [32], namely to the group of Spirocamallanus species characterized by the presence of wide caudal alae, three pairs of pedunculate preanal papillae and two unequal spicules, that are mostly parasites of marine fishes [37]. Most species of this group are characterized by the presence of two caudal spikes, one dorsal and one ventral, on a digital projection in the female [9,46], whereas these are lacking only in a few species. According to Petter et al. [38], Rigby and Adamson [39] and Moravec et al. [27], the shape and structure of the female tail appears to be constant within a species of Procamallanus (Spirocamallanus).
By the shape of the female tail and the absence of any terminal spikes, P.  [11] and P. (S.) sinespinis from the marine fish Pomadasys argenteus (Forsskål) (Haemulidae) off New Caledonia [26]. Vicente and Santos [45] did not report the presence of two terminal caudal spines in females of the inadequately described P. (S.) macaensis Vicente et Santos, 1972, a parasite of several species of marine fishes in Brazil [16], but these are present according to the later redescription of this species [42].
However, in contrast to the new species, the right spicule of P. murrayensis is distinctly shorter (290 lm vs 408-449 lm). The right spicules of P. mexicanus and P. sinespinis are only slightly longer (456-480 lm and 465-525 lm, respectively vs 408-449 lm) than those of P. dispar, but the number of spiral ridges in their buccal capsules is 10-12 (vs [12][13][14]; in addition, the male tail tip of these two species bears either a single conical cuticular spike (P. mexicanus) or a knob-like structure (P. sinespinis) (vs two, dorsal and ventral, terminal spikes are present); the female tail of P. mexicanus has a different shape, its anterior portion being narrow and conical (vs broad and posteriorly rounded). Moreover, P. mexicanus and P. murrayensis are parasites of freshwater fishes, whereas the hosts of P. dispar are marine fishes.
Moravec et al. [27] reported a nematode subgravid female, designated as Procamallanus (Spirocamallanus) sp. 3, from the marine fish Scolopsis bilineata (Bloch) (Nemipteridae) from off New Caledonia. The shape of its tail is similar to that of P. dispar and also the number (13) of spiral ridges in the buccal capsule corresponds to this species. However, the location of deirids is different (at the level of the nerve ring vs at the mid-way between the buccal capsule and the nerve ring), so that this specimen probably represents another species. Prevalence, intensity and details about fish: 1 fish infected/ 1 fish examined; 12 nematodes. The infected fish (Fish number: JNC3310) was 234 mm in fork length and 128 g in weight.
Etymology: The specific name of this nematode relates to the genitive form of the generic name of the host.

Remarks
Nematodes of the present material belong to the morphological group of Procamallanus (Spirocamallanus) species characterized by the presence of wide caudal alae, three pairs of pedunculate preanal papillae, two unequal spicules and two caudal spikes on a digital projection in the female. According to Yooyen et al. [46], in the Indo-Pacific region this group contains 23 nominal species reported mostly from marine fishes. However, the great majority of them are poorly described and should be considered species inquirendae [see also 31,40].
The following nine species of this morphological group from the Indo-Pacific region can be considered valid:  [27].
Of these, as compared with the new species, the right spicule is distinctly longer in P. gobiomori (318-348 lm vs 267-270 lm), P. pereirai (430 lm), P. rigbyi (315-360 lm), P. similis (435-492 lm) and P. variolae (327-357 lm); moreover, the spiral ridges in the buccal capsule are less numerous in P. gobiomori (8-10 vs 13-19), P. similis (10-12) and P. variolae (11)(12) and all these five species also differ in the family and order of their fish hosts (Perciformes: Eleotridae, Serranidae, Sciaenidae and Sillaginidae or Atheriniformes: Atherinidae vs Pleuronectiformes: Bothidae). The right spicule of P. anguillae is somewhat longer (289-384 lm vs 267-270 lm) than that of P. bothi n. sp., the spiral ridges are usually less numerous (10-15 vs 13-19) and both species differ in the type of the host (freshwater eel vs marine flatfish). The length of the right spicule in P. istiblenni and P. monotaxis is rather similar to that in the new species (263-302 lm and 279-315 lm, respectively vs 267-270 lm), but the spiral ridges are mostly less numerous (12-15 and 10-17, respectively vs 13-19); deirids of P. istiblenni are located in 2/3 of the distance between the base of the buccal capsule and the nerve ring (vs in the mid-length of this distance) and the excretory pore at the level of the posterior end of the muscular oesophagus (vs somewhat posterior to this level), and the female tail of P. istiblenni is more conical as compared with that of P. bothi n. sp.; the excretory pore of P. monotaxis is located short distance anterior to the posterior margin of the muscular oesophagus (vs somewhat posterior to the anterior end of the glandular oesophagus). Moreover, the hosts of P. istiblenni and P. monotaxis belong to different fish families and orders (Perciformes: Blenniidae and Lethrinidae, respectively vs Pleuronectiformes: Bothidae). Prevalence, intensity and details about fish: 1 fish infected/ 2 fish examined; 4 nematodes (Fish number: JNC2736). The infected fish was 185 mm in fork length and 68 g in weight.
Deposition of type specimens: Helminthological Collection, Institute of Parasitology, Biology Centre of the Czech Academy  four small inner papillae present near margin of oral aperture accompanied by distinct proximal pore; pair of small lateral amphids present (Figs. 5D, 6A and 6B). Buccal capsule orange, thick-walled, longer than wide, with simple, well-developed basal ring. Maximum width/length ratio of buccal capsule 1:1.25-1.27. Inner surface of capsule provided with 11-12 spiral ridges in lateral view, of which three incomplete (Figs. 5B, 5C and 5E). Muscular oesophagus shorter than glandular oesophagus; both parts of oesophagus somewhat expanded near their posterior ends (Fig. 5A). Intestine brown, narrow. Deirids small, simple, with rounded end situated just anterior to level of nerve ring (Figs. 5A, 5B, 5E, 5K and 6G). Excretory pore located at level of junction of both parts of oesophagus (Fig. 5A).
However, all these species, except for P. variolae, have deirids situated near the mid-point between the base of the buccal capsule and the nerve ring (vs deirids situated just anterior to the nerve ring). Based on this feature, the new species resembles only P. variolae, in which, however, the deirids are located slightly posterior (vs anterior) to the level of the nerve ring. Although P. variolae and P. hexophtalmatis n. sp. have the same numbers (11)(12) of spiral ridges in the buccal capsule and the body lengths of their gravid (larvigerous) females are identical (approximately 24 mm), the new species differs from P. variolae in the length ratio of the muscular and glandular portions of the oesophagus (1:1.5-1.6 in males and 1:1.7 in the gravid female vs 1:1.1-1.3 in males and 1:1.3 in the gravid female), location of the excretory pore at the level of the muscular and glandular oesophageal junction (vs somewhat posterior to this junction) and in that the vagina of the gravid female is directed anteriorly (vs posteriorly) from the vulva. Whereas the tail of both gravid and subgravid females in the new species is widely rounded (Figs. 5H and 5I), that of the gravid female of P. variolae is somewhat more conical. Moreover, both these species differ in the family of their fish hosts (Pinguipedidae vs Serranidae).
Moravec et al. [27] reported Procamallanus (Spirocamallanus) sp. 1 from P. hexophtalma in New Caledonia. However, although the general morphology of the only available specimen (subgravid female) was similar to that of P. hexophtalmatis n. sp., the spiral ridges in its buccal capsule were more numerous (16), deirids were located approximately at 2/3 of a distance between the base of the buccal capsule and the nerve ring and its tail was more conical as compared with that of the subgravid female of P. hexophtalmatis, resembling thus P. monotaxis [27]. Therefore, allocation of this specimen to P. hexophtalmatis is uncertain. Rigby and Adamson [39] reported P. monotaxis, originally described from a lethrinid fish from Hawaii [35], from Parapercis millepunctata (Günther) and members of several other fish families in French Polynesia, but this identification needs to be confirmed. In New Caledonia, P. monotaxis was recorded only from Lethrinus spp. [25].
The SEM examination of the first-stage larva of P. hexophtalmatis shows that the tail tip bears six digitiform processes (Figs. 6E and 6F). Similar caudal processes were previously observed in first-stage larvae of Camallanus cotti and C. lacustris [24] and those of two Procamallanus species from African freshwater fishes [18]. Apparently, these caudal processes serve the larva to better attach by its tail to the bottom, after the larvae are released into the water [24].
Procamallanus (Spirocamallanus) synodi n. sp.  Prevalence, intensity and details about fish: 1 fish infected/4 fish examined; 5 nematodes. The infected fish (Fish number JNC2756) was 120 mm in fork length and 20 g in weight.
Deposition of type specimens: Helminthological Collection, Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, České Budějovice, Czech Republic (male holotype and female allotype, both mounted on SEM stub, N-1203); Female (two ovigerous specimens; allotype; measurements of paratype in parentheses. Measurements of one nongravid specimen in brackets): Length of body 12. 10

Remarks
The present nematodes belong to the same morphological group of Procamallanus (Spirocamallanus) as the previous two species, P. bothi n. sp. and P. hexophtalmatis n. sp. By the length of the right spicule, they resemble nine very similar species occurring in the Indo-Pacific region, viz. P. anguillae, P. bothi n. sp., P. gobiomori, P. hexophtalmatis n. sp., P. guttatusi, P. istiblenni, P. monotaxis, P. rigbyi and P. variolae (see above). However, in having deirids located at or near the level of the nerve ring, they resemble only P. hexophtalmae and P. variolae, whereas deirids in other species are situated approximately in the mid-point between the buccal capsule and the nerve ring (in P. istiblenni in 2/3 of this distance).
In contrast to the new species, the female tail of P. hexophtalmatis n. sp. is widely rounded (vs conical), deirids are located slightly anterior to the level of the nerve ring (vs deirids at or just posterior to this level), the excretory pore is at the level of the junction of both parts of the oesophagus (vs at a short distance posterior to the anterior end of the glandular oesophagus), the vulva is slightly pre-equatorial (vs equatorial or somewhat postequatorial), the vagina is directed anteriorly (vs posteriorly) from the vulva and the males and females are distinctly longer (male 15.5 mm, gravid female 24.0 mm vs males 9.1-9.4 mm, subgravid females 11.7-12.1 mm).
Procamallanus (S.) variolae differs from the new species in the shape of the female tail (rounded vs conical), in having a distinctly pre-equatorial vulva (vs vulva equatorial or postequatorial), a largely different length ratio of the muscular and glandular parts of the oesophagus (1: 1.1-1.3 vs 1:1.3-1.9) and in that the males and females of this species are longer (males 10.5-12.7 mm, gravid female 24.5 mm vs males 9.1-9.4 mm and subgravid females 11.7-12.10 mm); the buccal capsule of P. variolae is larger (84-87 Â 60-66 lm in males and 99 Â 78 lm in female vs 66-81 lm in males and 66-72 Â 66-72 lm in subgravid females). Moreover, the hosts of both P. hexophtalmatis and P. variolae belong to other fish families than that of the new species (Pinguipedidae and Serranidae, respectively vs Synodontidae).
Procamallanus (S.) synodi n. sp. is the first species of this genus reported from a fish of the family Synodontidae.   Etymology: The specific name of this nematode relates to the genitive form of the generic name of the host.

Description
General: Medium-sized nematode with finely transversely striated cuticle. Mouth aperture oval, surrounded by 12 submedian cephalic papillae arranged in three circles, each formed by four papillae; papillae of outer circle larger; each of four small inner papillae present near margin of oral aperture accompanied by distinct proximal pore; pair of small lateral amphids present (Figs. 9D, 10A, 10B and 10C). Buccal capsule orange, thickwalled, longer than wide, with simple, well-developed basal ring. Maximum width/length ratio of buccal capsule 1:1.07-1.21. Inner surface of capsule provided with 11-12 spiral ridges in lateral view, 4-5 of them being incomplete (Figs. 9B, 9C and 10C). Muscular oesophagus shorter than glandular oesophagus; both parts of oesophagus slightly expanded near their posterior ends (Fig. 9A). Intestine brown, narrow. Deirids small, simple, with rounded end situated slightly anterior to level of nerve ring (Figs. 9B, 9G and 10D). Excretory pore located somewhat posterior to anterior end of glandular oesophagus (Fig. 9A).
Male (one specimen, holotype): Length of body 12.53 mm, maximum width 313. Buccal capsule including basal ring 87 long, its width 72; basal ring 12 long and 57 wide. Maximum width/length ratio of buccal capsule 1:1.21. Spiral ridges 12, 5 of which incomplete. Length of muscular oesophagus 435, maximum width 93; length of glandular oesophagus 748, maximum width 126; length ratio of muscular and glandular oesophagus 1:1.72. Length of entire oesophagus and buccal capsule representing 10% of body length. Deirids, nerve ring and excretory pore 279, 299 and 558, respectively, from anterior extremity. Posterior end of body ventrally bent, provided with wide, vesiculated caudal alae supported by pedunculate papillae; anteriorly alae interconnected by mound, forming a kind of pseudosucker, and posteriorly reaching to caudal terminal spines (Figs. 9E, 9F, 11A, 11B, 11C and 11D). Preanal papillae: three pairs of subventral pedunculate papillae, of which second and third pairs closer to each other than first

Remarks
The nematodes from T. lutescens belong to the same morphological group of Procamallanus (Spirocamallanus) as the species P. bothi n. sp., P. hexophtalmatis n. sp. and P. synodi n. sp. (see above). From the Indo-Pacific species of this group, P. pereirai and P. similis can be differentiated from P. thalassomatis n. sp. by possessing a distinctly longer right spicule (430 lm and 435-492 lm, respectively vs 330 lm) and P. bothi in having a shorter right spicule (267-270 lm), whereas the length of this spicule in the remaining species (P. anguillae, P. gobiomori, P. guttatusi, P. istioblenni, P. monotaxis, P. rigbyi and P. variolae) is rather similar. However, in having deirids located near the level of the nerve ring, they resemble only P. hexophtalmatis, P. synodi and P. variolae, whereas deirids in other species are situated approximately in the mid-way between the buccal capsule and the nerve ring (in P. istiblenni in 2/3 of this distance).
On the basis of the location of deirids somewhat anterior to the level of the nerve ring, P. thalassomatis n. sp. resembles P. hexophtalmatis n. sp., whereas deirids in P. variolae and P. synodi n. sp. are located at the level of the nerve ring or just posterior to this level. However, P. thalassomatis differs from P. hexophtalmatis in the vagina directed anteriorly (vs posteriorly) from the vulva; although the male body of the former species is shorter than that of the latter species (12.5 mm vs 15.5 mm), its buccal capsule is distinctly larger (87 Â 72 lm vs 75-84 Â 60 lm). The new species can be differentiated from P. variolae mainly by the length ratio of the muscular and glandular parts of the oesophagus (1:1.7-1.8 vs 1: 1.1-1.3) and by the percentage of the length of the oesophagus and buccal capsule of the entire body length of gravid females (7-8% vs 5%), whereas from P. synodi mainly by the shape of the female tail (broadly rounded vs conical) and the larger buccal capsule (87 Â 72 lm in male and 96-99 Â 90 lm in gravid female vs 66-81 Â 60-66 lm in male and 66-75 Â 66-72 lm in subgravid female). Moreover, the hosts of P. hexophtalmatis, P. synodi and P. variolae belong to other fish families than that of the new species (Pinguipedidae, Synodontidae and Serranidae, respectively vs Labridae).
Procamallanus (S.) thalassomatis n. sp. is the first species of this genus reported from a fish of the family Labridae. Deposition of voucher specimen: Muséum National d'Histoire Naturelle, Paris, France (1 specimen, MNHN JNC619A).

Remarks
Based on a single specimen (subgravid female) from S. bilineata off New Caledonia, Moravec et al. [27] described Procamallanus (S.) sp. 3, characterized by 13 spiral ridges in the buccal capsule and a broad tail with a short smooth projection. Two available specimens (also subgravid females) of the present material from the same host species, 14.12 and 18.84 mm long, are morphologically identical with that reported by Moravec et al. [27] and there is no doubt that both these forms belong to the same species. By the shape of the female tail and the absence of terminal spikes, this species is similar to P. (S.) dispar n. sp. and a few other congeners (see above). However, since conspecific males remain unknown, the species identification of these nematodes is impossible.

Remarks
Only a single male specimen of this nematode was available to study. Because some taxonomically important morphological features are found in females in this group of nematodes (e.g., the shape of the female tail), species identification was not possible. No species of Procamallanus has so far been reported from a carangid fish.    (Fig. 13B). Length of muscular oesophagus 490, maximum width 105; length of glandular oesophagus 843, maximum width 138 (Fig. 13A); length ratio of muscular and glandular oesophagus 1:1.18. Length of entire oesophagus and buccal capsule representing 12% of body length. Nerve ring 313 from anterior extremity. Deirids not located. Excretory pore at short distance posterior to posterior end of muscular oesophagus, at 734 from anterior end of body (Fig. 13A). Vulva postequatorial, 8.34 mm from anterior extremity, at 52% of body length. Vulval lips not elevated. Vagina directed posteriorly from vulva. Uterus filled with small amount of eggs. Tail broad, rounded, its posterior end abruptly narrowed to form digital protrusion provided with 1 small terminal cuticular knob; length of entire tail 163; digital protrusion 39 long, 15 wide (Figs. 13C and 13D).

Remarks
Due to availability of a single subgravid female, the species identification based on morphology is impossible. This species is characterized by the broadly rounded tail with a short projection without terminal cuticular spines. In this case, the shark apparently served as a postcyclic host, which had acquired the infection by feeding on the true definitive hosts (fish) of this nematode.
Site of infection: Collected from regurgitated digestive content of snake.
Deposition of voucher specimen: Muséum National d'Histoire Naturelle, Paris, MNHN JNB011.   (Fig. 14C). Length of muscular oesophagus 598, maximum width 105; length of glandular oesophagus 1020, maximum width 192 (Fig. 14A); length ratio of muscular and glandular oesophagus 1:1.71. Length of entire oesophagus and buccal capsule representing 7% of body length. Nerve ring 367 from anterior extremity. Deirids small, situated 243 from anterior extremity, approximately at mid-way between base of buccal capsule and nerve ring (Fig. 14B). Excretory pore located short distance posterior to posterior end of muscular oesophagus, at 816 from anterior end of body (Fig. 14A). Vulva postequatorial, 11.90 mm from anterior extremity, at 52% of body length. Vulval lips not elevated. Vagina directed posteriorly from vulva. Uterus filled with many eggs. Tail broad, somewhat conical, its posterior end abruptly narrowed to form digit-like protrusion provided with one small terminal cuticular knob; length of entire tail 122; digit-like protrusion 27 long, 15 wide (Figs. 14D and 14E).

Remarks
The presence of a single subgravid female but no male makes species identification of this nematode impossible. As in the previous case, it is apparent that the actual definitive host is a fish and the sea-snake acts only as a postcyclic host, which acquired the infection by feeding on fish. The nematode was collected from the regurgitated digestive content of a snake induced by manipulation, no identifiable prey fish was recovered.
Camallanus carangis Olsen, 1954 [23,27]. The present survey extends considerably the range of hosts of C. carangis in New Caledonia, now including 15 fish species of the perciform families Carangidae, Lutjanidae, Mullidae, Nemipteridae and Serranidae, and a representative of the clupeiform family Chirocentridae. Of them, however, gravid (= larvigerous) females of this nematode have  [20,21,44]. The present record of the C. carangis fourth-stage larva in the digestive tract of a sea-snake indicates that the snake acquired this infection while feeding on fish.
To date, C. carangis is the only representative of Camallanus parasitizing marine fishes in New Caledonian waters. Another congeneric species, C. cotti, a parasite of freshwater fishes, was introduced into New Caledonia [24].

Discussion
All species of Procamallanus (Spirocamallanus) reported in this study belong to the morphological group of nematodes characterized by the presence of wide caudal alae, three pairs of pedunculate preanal papillae and two unequal spicules; as mentioned above, this mostly includes parasites of marine perciform fishes [37,38]. Many species with these characteristics have been, often inadequately, described from different geographical zones, which makes a thorough comparison of them almost impossible. This situation is more complicated by the fact that some taxonomically important morphological features of these nematodes (e.g., the shape and position of deirids, excretory pore or the number and distribution of postanal papillae) are not easily observed under the light microscope and, consequently, that some insufficiently described species are reported from numerous, often unrelated hosts.
According to Petter et al. [38], Rigby and Adamson [39] and Moravec et al. [29], the shape and structure of the female tail of these nematodes appear to be constant within a species in Procamallanus (Spirocamallanus). Most species possess 2-4 terminal spines on the digital caudal projection in the female, whereas these are lacking only in a few species. Nevertheless, the morphology of all these species is rather similar. Although the division of Procamallanus (Spirocamallanus) species according to geographical zones by Andrade-Salas et al. [2] has been used by some authors [22,27,31,39,40] for the comparison of species, recent detailed morphological studies of some of these nematodes, including SEM, indicate a certain degree of their host specificity (approximately at the level of fish family), which should also be considered when evaluating these nematodes. This is supported by the present findings.
A quite different situation is regarding the species C. carangis, which, in New Caledonia, has been reported from 15 host species belonging to six fish families. This is not surprising, because a low degree of host specificity is well known for some other species of Camallanus, for example C. cotti, C. lacustris, C. oxycephalus or C. truncatus (Rudolphi, 1814). This is related with the circulation of these parasites in the environment, when different categories of hosts are employed during the development of these nematodes, i.e., different fishes may play a role of paratenic, definitive, paradefinitive or postcyclic hosts. Some aquatic snakes were found to be postcyclic hosts of the European species C. lacustris and C. truncatus [21].
Our records might be the first parasitological records for L. saintgironsi, a species recently described [6]; the species is endemic to New Caledonia [8] and sympatric with another species, L. laticaudata (Linnaeus) [5]. Its diet consists of non-spiny anguilliform fish, with the lipspot moray Gymnothorax chilospilus Bleeker representing about half of the prey [5]. The present records of Procamallanus (S.) sp. 3 subgravid female and that of C. carangis four-stage larva in the sea snakes L. saintgironsi indicate that these hosts acquired the infection with camallanids by feeding on fish hosts -probably morays -of these nematodes. Camallanids may survive in the digestive tract of fish-eating snakes for a long period (up to several months), as observed in C. truncatus overwintering in the European colubrid snake Natrix tessellata (Laurenti) [19]; in this case, it served as the postcyclic host. Regarding the above-mentioned camallanids in L. saintgironsi, these snakes served as postcyclic and paratenic hosts, respectively.