Table of Contents
ISRN Zoology
Volume 2011, Article ID 341640, 12 pages
http://dx.doi.org/10.5402/2011/341640
Review Article

Some Rare and Insufficiently Studied Snailfish (Liparidae, Scorpaeniformes, Pisces) in the Pacific Waters off the Northern Kuril Islands and Southeastern Kamchatka, Russia

1Laboratory of Atlantic Basin, Department of International Fisheries Cooperation, Russian Federal Research Institute of Fisheries and Oceanography (VNIRO), 17 V. Krasnoselskaya, Moscow 107140, Russia
2Kamchatka Branch of Pacific Institute of Geography, Far East Branch of Russian Academy of Sciences, 6 Partizanskaya, Petropavlovsk-Kamchatsky 683000, Russia

Received 19 January 2011; Accepted 13 March 2011

Academic Editors: D. Park and M. Mooring

Copyright © 2011 A. M. Orlov and A. M. Tokranov. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Spatial and vertical distributions, size-weight compositions, age, and diets of 10 rare or poorly known snailfish (Liparidae) from the Pacific off the southeastern Kamchatka and the northern Kuril Islands are described. The species include blacktip snailfish Careproctus zachirus, Alaska snailfish C. colletti, blacktail snailfish C. melanurus, proboscis snailfish C. simus, falcate snailfish C. cypselurus, big-disc snailfish Squaloliparis dentatus, longtip snailfish Elassodiscus obscurus, slender snailfish Paraliparis grandis, gloved snailfish Palmoliparis beckeri, and stout snailfish Allocareproctus jordani. These species inhabit a wide range of depths. Careproctus melanurus, C. cypselurus, E. obscurus, P. grandis, and C. colletti are the deepest; C. simus and S. dentatus occur mostly between 300 and 600 m; the three other species seldom occur at depths of 150–200 m. The life span of these species is 10–13 years, and specimens of age classes 2–5 constitute the bulk of catches. All except A. jordani are benthophages that eat small crustaceans, shrimps, hermit crabs, and amphipods. A. jordani consumes crustaceans and also polychaete worms, sea snails, octopi, brittle stars, juvenile fish, and fishery offal.

1. Introduction

The family Liparidae is one of the most diverse and abundant fish families in polar and deep-sea habitats [1] and includes species that occur from littoral to ultra-abyssal depths [2]. There are about 50 species in this family in Pacific waters off Kamchatka and the northern Kuril Islands, constituting almost 10% of the total number of fish species inhabiting this area [37]. These fish are relatively abundant in number and biomass on the lower part of the continental shelf as well as on the upper continental slope (100–800 m) in most areas of the Far Eastern Seas [3, 4, 811]. They are food for and potential food competitors of commercial fish species in groundfish communities. However, until now, snailfish have been poorly studied even in terms of their taxonomy [1]. Published information regarding occurrence, spatial-bathymetric distribution, and biology of most snailfish in the North Pacific as a whole and in waters adjacent to the Kuril Islands and Kamchatka in particular is extremely limited. The majority of papers containing information on the North Pacific liparids [1220] are dealing mostly with their taxonomy, geographic and bathymetric ranges, new records, and eventually contain limited information on general biology.

In 1993–2002, in a program to study poorly known and underexploited fish of the continental slope of the Far Eastern Seas in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka (the area from 47° 50′ to 52° 00′ N, depths of 83–850 m), the Russian Federal (VNIRO), Kamchatka (KamchatNIRO), and Sakhalin (SakhNIRO) Research Institutes of Fisheries and Oceanography jointly carried out more than 60 fishery research cruises onboard Japanese trawlers specially equipped for bottom trawling in areas of the continental slope with rugged topography, in the course of which new data on snailfish distribution and biology were collected.

We provide information in this paper regarding occurrence, spatial-bathymetrical distribution, size-age composition and diets of 10 rare or insufficiently studied snailfishes in Pacific waters off the northern Kuril Islands and southeastern Kamchatka, including Alaska snailfish Careproctus colletti Gilbert, 1896, blacktip snailfish C. zachirus Kido, 1985, blacktail snailfish C. melanurus, Gilbert, 1892, proboscis snailfish C. simus, Gilbert, 1896, falcate snailfish C. cypselurus (Jordan and Gilbert, 1898), big-disc snailfish Squaloliparis dentatus (Kido, 1988), longtip snailfish Elassodiscus obscurus Pitruk et Fedorov, 1993 (new common English name proposed), slender snailfish Paraliparis grandis Schmidt, 1950, gloved snailfish Palmoliparis beckeri Balushkin, 1996 and stout [7] or cherry [21] snailfish Allocareproctus jordani (Burke, 1930).

2. Material and Methods

Data for this paper are based on analysis of catches of approximately 11,000 bottom-trawl hauls at depths of 83–850 m (near-bottom temperatures were measured for most hauls) carried out in April–December 1993–2002 aboard the Japanese trawlers “Tomi-Maru-53,” “Tomi-Maru-82,” and “Tora-Maru-58” under the VNIRO-SakhNIRO-KamchatNIRO joint program (hereafter referred to as the 1993–2002 survey). Hauls were made 24 hours a day using bottom trawls with vertical opening of 5–7 m and horizontal opening of 25 m (the parameters of the trawl openings were checked by equipment) at an average speed of 3.6 knots. Because trawl duration varied from 0.5 to 10 hours, all the catches were later normalized to a standard one-hour haul. Distributions of individual species by depth and bottom temperature were analyzed by frequency of occurrence (in percent), calculated based on average catch per hour.

Snailfish were identified to species using keys and descriptions by Gilbert and Burke [22], Burke [23], Hart [24], Stein [25], Kido [2628], Masuda et al. [29] Pitruk and Fedorov [3032], Amaoka et al. [33] and Balushkin [34].

To study size-age composition, length measurements and biological analyses of the 10 snailfish species studied were used (datasets for each of the species are given in Table 1). Age was determined by otoliths using the “break and burn” technique. We assumed annuli were annual. Diet was determined from the results of field analyses made in August–December 1996–2002.

tab1
Table 1: Number of specimens examined in this study.

3. Results and Discussion

3.1. Occurrence and Bathymetry

Blacktip Snailfish Careproctus zachirus
First described in 1985 from the Bering Sea [27]. It is a high-boreal Asiatic species, from the northern part of the Sea of Okhotsk, off the northern Kuril Islands, eastern Kamchatka, and in the western part of the Bering Sea off the western Aleutian Islands [57, 11, 35, 36]. The 1993–2002 survey observed it between 47° 50′ to 51° 30′ N, with maximum catches (>25 specimens/h) from the southern part of the surveyed area, preliminarily from the continental slope of the northern Kuril Islands (Figure 1).
C. zachirus is a mesobenthic species inhabiting depths of 214–850 m [6, 7]. This species was caught at depths of 150–800 m with near-bottom temperatures of 3.0–3.6°C and concentrated mainly in 400–500 m where more than 56% of the specimens were observed (Table 2).

tab2
Table 2: Bathymetric distribution (percentage of relative abundance within certain depth range) of different snailfish species off the northern Kuril Islands and southeastern Kamchatka.
341640.fig.001
Figure 1: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Careproctus zachirus in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, AprilDecember 19932002 (numbers are maximum catches; thin lines are isobaths at 100, 200, 500, and 1000 m).

Alaska Snailfish Careproctus colletti
This is a boreal Asiatic species widely distributed in the northern part of the Sea of Japan, Sea of Okhotsk, and Bering Sea [7, 37], and in Pacific waters off Hokkaido [33], northern Kuril Islands, southeastern Kamchatka [5, 6, 11, 35], and the Gulf of Alaska [36]. We found C. colletti throughout the survey area with maximum catches (>5 specimens/h) recorded in its northernmost and southernmost parts (Figure 2).
C. colletti is a part of the mesobenthic community and is known from depths of 64–1,350 m [6, 7]. We found it at 360–700 m at near-bottom temperatures of 3.0–3.6°C. The majority of specimens (about 83%) were caught between 400 and 600 m (Table 2).

341640.fig.002
Figure 2: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Careproctus colletti in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, April–December 1993–2002.

Blacktail Snailfish Careproctus melanurus
This is a boreal Pacific species widely distributed in the north Pacific from the Bering Sea to the Sea of Japan, and along the Pacific coast of Japan in the west to California in the east [7, 36]. Until recently, C. melanurus was known primarily from the American coast from British Columbia to California [23, 24, 3841]. In Asian waters, it is known from the Bering Sea [42, 43], the Pacific off southeastern Kamchatka, the northern Kuril Islands [5, 6, 43], and off Japan [44]. Previous information regarding its distribution off the Pacific coast of Kamchatka and the northern Kuril Islands was limited [35, 43]. We found it in the Pacific coast from 48° 00′ to 52° 00′ N (Figure 3). Most catches were recorded in the central and northern parts of the survey area, although one catch of maximum size (>10 specimens/h) was from the south on the eastern slope of underwater plateau.
Unlike C. zachirus and C. colletti, C. melanurus is a bathybenthic species known from depths of 89–2,286 m, but primarily between 500 and 1,600 m [6, 7, 45]. Our data showed this species occurred at depths from 285 to 800 m, with near-bottom temperatures of 3.0–3.6°C, but most specimens (over 66%) were caught in 500–700 m (Table 2).

341640.fig.003
Figure 3: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Careproctus melanurus in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, April–December 1993–2002.

Proboscis Snailfish Careproctus simus
This species is boreal Asiatic, widely distributed in the northern part of the Pacific Ocean between 45° N and 60° N including the Sea of Japan, the Sea of Okhotsk off Hokkaido and southeastern Sakhalin, the Bering Sea, the Aleutian Islands, and the northern Kuril Islands [7, 27, 36, 46]. However, data on its spatial-bathymetric distribution is limited by capture depths. In our studies, only 1-2 specimens/h were registered in catches in August–December 1998–2002 in the southernmost part of the surveyed area, along the eastern slope of the northern part of the outer Kuril chain (Figure 4).
Data from Chernova et al. [36] suggest that C. simus is a rare mesobenthic species known from depths of 380–800 m. Our data from catches in the Pacific off the northern Kuril Islands in August–December showed it occurs at depths from 370 to 630 m at near-bottom temperatures of 3.4–3.6°C, with most (>83%) caught at 400–600 m (Table 2).

341640.fig.004
Figure 4: Capture sites (*) of Careproctus simus off the northern Kuril Islands, August–December 1998–2002.

Falcate Snailfish Careproctus cypselurus
This is a boreal Pacific species pervasive in the northern Pacific Ocean from the Bering Sea to the Sea of Japan and the Pacific coast of Japan in the west to British Columbia and the states of Washington and Oregon in the east [36, 37], and off the northern Kuril Islands and southeastern Kamchatka [5, 6, 11]. Our studies confirm its occurrence throughout the area (Figure 5). However, it was observed most frequently to the southeast (47° 50′ N to 48° 50′ N), where maximum number of C. cypselurus (854 specimens) was caught, although usually catches were fewer than 30–50 specimens/h.
C. cypselurus is a bathybenthic species known from depths of 35–1,993 m, but inhabiting mainly depths of 450–1,500 m [6, 7, 36]. We found this snailfish at depths of 330–800 m, but most were at 400–600 m (Table 2), where 72% were caught.

341640.fig.005
Figure 5: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Careproctus cypselurus in the Pacific waters off northern Kuril Islands and southeastern Kamchatka, AprilDecember 1993–2002.

Longtip Snailfish Elassodiscus obscurus
This species was described from the southern Sea of Okhotsk [30] and is as a wide-boreal Asiatic species distributed in the Sea of Okhotsk off southwestern Kamchatka, in the Pacific off Kamchatka and the Kuril Islands [6, 7, 36], and in the eastern [47] and western Bering Sea (60° 48.9′ N, 179° 03.7′ E, 660–665 m, 1 specimen; 61° 32.6′ N, 177° 52.1′ E, 460–450 m, 9 spec.; 61° 33.5′ N, 178° 04.8′ E, 320 m, 1 spec.; 60° 21.3′ N, 171° 46.0′ E, 670–675 m, 1 spec. Our data). We found that E. obscurus is a common and rather abundant species on the Pacific side of the northern Kuril Islands and the southeastern coast of Kamchatka [5, 11].
E. obscurus occurred on the continental slope of the entire Pacific coast survey area (Figure 6). However, maximum catches (up to 1,400–1,500 specimens/h) came from southeastern Kamchatka (from 50° 50′ N to 51° 30′ N).
E. obscurus is a mesobenthic species inhabiting depths of 161–1,773 m, but predominantly occurring in 550–1,200 m [6, 7]. This snailfish occurred at depths of 260–800 m (Table 2) with near-bottom temperatures of 0.4–3.7°C, with about 50% caught in 500–600 m.

341640.fig.006
Figure 6: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Elassodiscus obscurus in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, AprilDecember 1993–2002.

Slender Snailfish Paraliparis grandis
First described in 1950 based on a single specimen caught in the northern Sea of Okhotsk at a depth of 592 m [48]. It is known to be widely distributed in the Sea of Okhotsk and the western Bering Sea [7, 26, 28, 49, 50]. In Pacific waters off the northern Kuril Islands and southeastern Kamchatka, P. grandis is common and even rather abundant [5, 6, 11].
Similar to E. obscurus, P. grandis is pervasive throughout the area (Figure 7). However, its maximum catches (>1,000 specimens/h) were abeam the Fourth Kuril Strait, southeast of Paramushir Island.
It is a mesobenthic species known from 105–1,995 m, but inhabiting mainly depths of 450–900 m [6, 7]. We caught it at depths of 260–800 m with near-bottom temperatures of 2.6–3.7°C, although approximately 82% were caught between 500 and 700 m (Table 2).

341640.fig.007
Figure 7: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Paraliparis grandis in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, AprilDecember 1993–2002.

Big-Disc Snailfish Squaloliparis dentatus
First described from the Sea of Okhotsk waters off the Hokkaido as Careproctus dentatus, [28], it is now placed in the genus Squaloliparis, [31]. It is fairly common and widely distributed in the bathyal of the Sea of Okhotsk as well as in the Pacific off the northern Kuril Islands and southeastern Kamchatka [6, 7, 11, 31, 36]. We captured it only to the south from 47° 50′ N to the Fourth Kuril Strait (Figure 8), with the maximum catches (the largest with 187 specimens/h) registered on the slopes of the underwater elevation.
S. dentatus is a mesobenthic species known from depths of 120–900 m [6, 7, 31]. In the Sea of Okhotsk, most specimens were caught in 400–500 m [31]. Catches from Pacific waters off the Kuril Islands were at depths from 260 to 570 m, with near-bottom temperatures of 1.6–3.4°C. About 61% were from 300–400 m (Table 2).

341640.fig.008
Figure 8: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Squaloliparis dentatus in the Pacific waters off the northern Kuril Islands, JulyNovember, 1995–2002.

Gloved Snailfish Palmoliparis beckeri
Described from the Pacific off the northern Kuril Islands [34] and subsequently characterized as a rare, widely distributed boreal Asiatic species from off the Kuril Islands and southeastern Kamchatka [6, 7, 36]. All known specimens (about 30) were caught in Pacific waters off the northern Kuril Islands in the area to the south of the Fourth Kuril Strait [11, 34, 35, 51]. Our data show P. beckeri occurring only along the continental slope from 47° 50′ N to the Fourth Kuril Strait, with maximum catches >2 specimens/h (Figure 9).
P. beckeri is a mesobenthic species inhabiting depths of 200–800 m [7]. Our specimens were collected from that depth range, with near-bottom temperatures of 2.0–3.8°C. Most specimens (>65%) were from depths of 300–500 m (Table 2).

341640.fig.009
Figure 9: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Palmoliparis beckeri in the Pacific waters off northern Kuril Islands, AprilDecember 1995–2002.

Stout or Cherry Snailfish Allocareproctus jordani
Originally described as Careproctus gilberti based on the holotype and only specimen caught in the Pacific off Honshu [52], Burke [23] later described it as Careproctus jordani. It was subsequently allocated to the genus Allocareproctus [32]. Sheiko and Fedorov [7] consider the species to be a junior synonym of Allocareproctus pycnosoma, [22], although Orr and Busby [21] consider A. jordani as valid. A. jordani is a widely distributed boreal Asiatic species occurring in the Pacific off Japan (Sagami Bay), eastern Sea of Okhotsk, the Kuril Islands and eastern Kamchtka, eastern Bering Sea, and central and eastern Aleutian Islands [57, 11, 21, 32, 35, 36]. We collected it from 47° 50′ to 51° 00′ N (Figure 10), but maximum catches (>10 specimens/h) were obtained from the slopes of underwater plateau and off the Fourth Kuril Strait. To the north, only a few specimens were caught.
This species is a mesobenthic species known from depths of 75–700 m [7]. We caught it between 130–750 m, with near-bottom temperatures of 1.3–3.6°C (Table 2), although most specimens (>87%) were caught in 300–500 m.

341640.fig.0010
Figure 10: Distribution and relative abundance categorized by CPUE (specimens per hour trawling) of Allocareproctus jordani in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, April–December 1993–2002.
3.2. Length and Weight

Of the five species of Careproctus considered here, C. melanurus and C. colletti reach maximum size in Pacific waters off southeastern Kamchatka and the northern Kuril Islands.

Careproctus melanurus were 18–51 cm (35.4 cm average) in length and 100–1,700 g (728 g average) in weight; C. colletti were 14–44 cm (30.1 cm average) and 70–1,200 g (381 g average; Figure 11, Table 3), although specimens of C. melanurus of 30–40 cm (77%) and 450–900 g (68%) and C. colletti 23–32 cm (54%) and 200–400 g (58%) were more abundant. Maximum length of C. melanurus in American waters is estimated to be 26 cm [53], although on the Oregon slope specimens of up to 31.2 cm have been caught [54]. Our data suggested that C. melanurus is significantly larger off the Asian coast; in the western Bering Sea it reaches 54 cm length [43].

tab3
Table 3: Weight composition (number of fish within certain weight range) of different snailfish species off the northern Kuril Islands and southeastern Kamchatka.
fig11
Figure 11: Size compositions of Careproctus simus (1), C. zachirus (2), C. cypselurus (3), C. colletti (4), and C. melanurus (5) in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, 1993–2002.

Both C. zachirus and C. cypselurus are smaller than C. melanurus and C. colletti, with maximum lengths of only 32 and 36 cm, respectively [35, 55]. In our data, C. zachirus ranged from 19 to 32 cm (24.7 cm average) and 80 to 500 g (194 g average); C. cypselurus ranged from 26 to 36 cm (30.6 cm average) and 100 to 800 g (291 g average). Smaller C. zachirus of 24–28 cm (56%) and 100–300 g (>82%) and C. cypselurus of 28–34 cm (84%) and 100–400 g (83%) were more common (Figure 11, Table 3).

The maximum known length of C. simus is 18.6 cm [46]. Off the northern Kuril Islands, individuals of 12–19 cm (15.6 cm average) (Figure 11) weighing 30–100 g (75 g average) occurred in trawl catches, but fish of 15–18 cm in length (69%) dominated.

Tokranov [55] recorded the maximum sizes of Elassodiscus obscurus and Paraliparis grandis in the Pacific off the southeastern Kamchatka and northern Kuril Islands at 35–40 cm and 0.6 kg. Our E. obscurus were represented by fish of 17–35 cm (26.2 cm average) and 100–600 g (250 g average); P. grandis were 19–40 cm (31.3 cm average) and 120–600 g (250 g average). However, E. obscurus of 22–30 cm (84%) and 100–400 g (85%) and P. grandis 28–36 cm (>89%) and 100–400 g (about 96%; Figure 12, Table 3) formed most of the catches.

341640.fig.0012
Figure 12: Size compositions of Elassodiscus obscurus (1) and Paraliparis grandis (2) in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, 1993–2002.

In the literature, S. dentatus reaches 34.6 cm [31] and P. beckeri and A. jordani 38 cm and 1 kg [34, 35]. We collected S. dentatus of 20–39 cm (29.6 cm average) and 100–1,300 g (680 g average); P. beckeri of 15–38 cm (28.9 cm average) and 60–1,000 g (414 g average), and A. jordani of 10–38 cm (21.6 cm average) and 50–1,000 g (210 g average; Figure 13, Table 3). However, S. dentatus of 26–34 cm (54%) weighing 500–900 g (over 65%), P. beckeri of 26–36 cm (78%) and 100–500 g (about 67%), and A. jordani of 16–24 cm (54%) weighing less than 200 g (65%) occurred most frequently.

341640.fig.0013
Figure 13: Size compositions of Allocareproctus jordani (1), Squaloliparis dentatus (2), and Palmoliparis beckeri (3) in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka, 1995–2002.

Length-weight relationships were obtained for all snailfish species considered here (Table 4). The values of parameter 𝑏 for the majority of the species examined (with the exception of C. simus and P. grandis) were generally within the normal range (2.5–3.5) for fish [56], indicating isometric growth during their life span [57]. Species with similar values of parameters 𝑎 and 𝑏 are C. cypselurus, C. melanurus, E. obscurus, and S. dentatus, indicating similar growth in these species.

tab4
Table 4: Parameters and coefficient of determination (R2) of equation of total length- (TL-) weight (W) relationship W = aTLb in different snailfish species off the northern Kuril Islands and southeastern Kamchatka.
3.3. Age and Age Composition

Based on our age determinations from otoliths and on the sizes of the specimens we collected, we conclude that the maximum age of the species considered here and of species of this family is less than 10–13 years [35, 55], and that specimens of 2–5 age classes (Table 5) constitute the main part (73–97%) of the catch of each species (Figure 14).

tab5
Table 5: Lengths (cm) and weights (g) of seven snailfish species related to age off the northern Kuril Islands and southeastern Kamchatka (numerators: mean total lengths ± standard error, range is given in parentheses, sample size is marked by asterisk; denominators: mean body weights ± standard error).
341640.fig.0014
Figure 14: Age compositions of Careproctus cypselurus (1), Elassodiscus obscurus (2), and Paraliparis grandis (3) in the Pacific off northern Kuril Islands and southeastern Kamchatka, 1993–2002.
3.4. Diet

We found that all the species we studied are benthophages feeding mainly on bottom and near-bottom organisms, primarily crustaceans [20, 35, 58]. The four species of genus Careproctus (C. zachirus, C. colletti, C. melanurus, C. cypselurus) and also E. obscurus, P. grandis, and P. becker eat a rather limited food spectrum consisting of 2–5 groups of invertebrates and fish (Table 6). However, small shrimps (mainly of family Hippolytidae), hermit crabs Pagurus spp., and amphipods (total occurrence greater than 80–90%) are their main diet. A. jordani has a significantly broader diet of crustaceans (40%), polychaete worms, sea snails (Gastropoda), octopi (Octopoda), brittle stars (Ophiuroidea), as well as juvenile fish and fishery offal.

tab6
Table 6: Frequency of occurrence of food items in stomachs of eight snailfish species off the northern Kuril Islands and southeastern Kamchatka.

4. Conclusion

The results of research conducted in 1993–2000 allowed us to conclude that proboscis snailfish, big-disc snailfish, and gloved snailfish occur only in a limited part of the Pacific continental slope off the northern Kuril Islands south of the Fourth Kuril Strait; the maximum catches of all these three species have been recorded exclusively in the area of the underwater elevation in the northern link of the outer ridge of the Kuril chain. The range of stout snailfish and blacktip snailfish is somewhat wider: the former was found up to 51° 00′ N; the latter at up to 51° 30′ N, though their greatest catches tended to be taken near the underwater elevation and Fourth Kuril Strait too. Unlike them, the falcate snailfish, blacktail snailfish, longtip snailfish, slender snailfish, and Alaska snailfish were observed throughout the entire area surveyed during the period of study. However, while the largest catches of the former species occurred mostly in the southern part of that area, the biggest catches of the blacktail, longtip, and slender snailfish were, in contrast to that, recorded in the northern and central parts. The Alaska snailfish used to be caught in about equal numbers both in the north and in the south of the area examined on the Pacific side of the northern Kuril Islands and southeastern Kamchatka.

All the snailfish surveyed inhabit a broad bathymetric range between April and December, though the deepest species of them are the blacktail, falcate, longtip, slender, and Alaska snailfish whose upper range limit does not rise over 260–300 m; those fish stay mostly at bottom temperatures over 3°C. The proboscis snailfish and big-disc snailfish are found mostly within 300–600 m. Unlike these fish, the other three species, especially stout and blacktip snailfish, occur sporadically at 150–200; the gloved and stout snailfish can fairly often be found at much lower bottom temperatures.

The life span of all the snailfish examined, as in most of the other representatives of this family, does not exceed 10–13 years while the catches of each of them taken in the Pacific off the northern Kuril Islands and southeastern Kamchatka basically (73–97%) comprise individuals aged 2–5 years.

The body length-weight relationship analysis of the snailfish studied shows that despite the differences in body shape most of them have isometric pattern of growth.

All the snailfish examined except stout snailfish are benthophagous with rather narrow food ranges. Their major dietary components are various small bottom or near-bottom crustaceans (shrimp, hermit crabs Pagurus spp., and amphipods). Unlike them, the diet of stout snailfish is much wider; in addition to crustaceans, it includes polychaet worms, sea snails Gastropoda, bivalves Bivalvia, brittle stars Ophiuroidea, as well as young fish and fishey offal.

Acknowledgments

Authors would like to express their gratitude to all the scientists of VNIRO, KamchatNIRO, SakhNIRO and other institutions who, between 1993 and 2002, collected data used in this paper. We also thank the assistance of Tomio Iwamoto (Department of Ichthyology, California Academy of Sciences, San Francisco, USA) who helped improve the English.

References

  1. S. W. Knudsen, P. R. Møller, and P. Gravlund, “Phylogeny of the snailfishes (Teleostei: Liparidae) based on molecular and morphological data,” Molecular Phylogenetics and Evolution, vol. 44, no. 2, pp. 649–666, 2007. View at Publisher · View at Google Scholar · View at Scopus
  2. G. U. Lindberg, “Family liparids, or snailfishes (Liparidae),” in Wildlife, T. S. Rass, Ed., vol. 1, part 4, pp. 579–581, Prosveshcheniye, Moscow, Russia, 1971. View at Google Scholar
  3. L. A. Borets, Bottom Ichthyocenes of the Russian Far East Seas Shelf: Composition, Structure, Functioning Elements and Commercial Importance, TINRO-Center, Vladivostok, Russia, 1997.
  4. L. A. Borets, Annotated List of Fishes of the Far East Seas, TINRO-Center, Vladivostok, Russia, 2000.
  5. A. M. Orlov, “Demersal ichthyofauna of Pacific waters around the Kuril Islands and southeastern Kamchatka,” Biologiya Morya, vol. 24, no. 3, pp. 144–160, 1998 (Russian). View at Google Scholar · View at Scopus
  6. V. V. Fedorov, “Species composition, distribution and habitation depths of the Northern Kuril Islands fish and fish-like species,” in Commercial and Biological Studies of Fishes in the Pacific Waters of the Kuril Islands and Adjacent Areas of the Okhotsk and Bering Seas in 1992–1998, B. N. Kotenev, Ed., pp. 7–41, VNIRO, Moscow, Russia, 2000. View at Google Scholar
  7. B. A. Sheiko and V. V. Fedorov, “Class cephalaspidomorphi—lampreys. Class chondrichthyes—cartilaginous fishes. Class holocephali—chimaeras. Class osteichthyes—bony fishes,” in Catalogue of Vertebrates of Kamchatka and Adjacent Waters, R. S. Moiseev and A. M. Tokranov, Eds., chapter 1, pp. 7–69, Kamchatskii Pechatnyi Dvor, Petropavlovsk-Kamchatsky, Russia, 2000. View at Google Scholar
  8. E. N. Il'insky, “Long-term changes of catch composition of dominant bottom fish on the continental slope of the Far East seas,” Izvestiya TINRO, vol. 111, pp. 67–78, 1990 (Russian). View at Google Scholar
  9. Y. I. Dudnik and V. N. Dolganov, “Distribution and fish stocks on the continental slope of the Okhotsk Sea and Kuril Islands,” Voprosy Ikhtiologii, vol. 32, no. 4, pp. 83–98, 1992 (Russian). View at Google Scholar
  10. A. M. Orlov, A. M. Tokranov, and S. N. Tarasyuk, “Composition and dynamics of the bottom fish communities on the Pacific upper continental slope off the northern Kuril Islands and southeast Kamchatka,” Voprosy Rybolovstva, vol. 1, no. 4, pp. 21–45, 2000 (Russian). View at Google Scholar
  11. A. M. Tokranov, “Species composition and spatial distribution of snailfishes (Liparidae) in the Pacific waters of southeastern Kamchatka and northern Kuril Islands,” Voprosy Ikhtiologii, vol. 40, no. 2, pp. 176–186, 2000 (Russian). View at Google Scholar
  12. V. K. Soldatov and G. U. Lindberg, “A review of the fishes of the seas of the Far East,” Izvestiya TINRO, vol. 5, pp. 1–576, 1930 (Russian). View at Google Scholar
  13. A. Y. Taranets, “Handbook for identification of fishes of Soviet Far East and adjacent waters,” Izvestiya TINRO, vol. 11, pp. 1–200, 1937 (Russian). View at Google Scholar
  14. A. P. Andriashev, An Outline of the Zoogeography and Origin of the Fish Fauna of the Bering Sea and Neighboring Waters, Izdatel'stvo Leningradskogo Gosudarstvennogo Universiteta, Leningrad, Russia, 1939.
  15. A. P. Andriashev, Fishes of the Northern Seas of the U.S.S.R., Izdatel'stvo Akademii Nauk SSSR, Moscow, Russia, 1954.
  16. T. Ueno, “List of the Marine fishes from the waters of Hokkaido and its adjacent regions,” Scientific Reports of the Hokkaido Fisheries Experimental Station, vol. 13, pp. 61–102, 1971. View at Google Scholar
  17. R. H. Parrish, “Symbiosis in the blacktail snailfish, Careproctus melanurus, and the box crab, Lopholithodes foraminatus,” California Department of Fish and Game, vol. 58, no. 3, pp. 239–240, 1972. View at Google Scholar
  18. J. C. Quast and E. L. Hall, List of Fishes of Alaska and Adjacent Waters with a Guide to some of Their Literature, NOAA Tech. Rep. NMFS SSRF-658, United States Department of Commerce, 1972.
  19. M. J. Allen and G. B. Smith, Atlas and Zoogeography of Common Fishes in the Bering Sea and Northeastern Pacific, NOAA Technical Report NMFS, 66, US Department of Commerce, 1988.
  20. A. M. Tokranov, “Feeding of snailfishes (Liparidae) in the Pacific waters of southeastern Kamchatka and northern Kuril Islands,” Voprosy Ikhtiologii, vol. 40, no. 4, pp. 530–536, 2000 (Russian). View at Google Scholar
  21. J. W. Orr and M. S. Busby, “Revision of the snailfish genus Allocareproctus Pitruk et Fedorov (Teleostei: Liparidae), with descriptions of four new species from the Aleutian Islands,” Zootaxa, no. 1173, pp. 1–37, 2006. View at Google Scholar · View at Scopus
  22. C. H. Gilbert and C. V. Burke, “Fishes from Bering Sea and Kamchatka,” The Bulletin of the United States Bureau of Fisheries, vol. 30, pp. 31–96, 1912. View at Google Scholar
  23. V. Burke, “Revision of the fishes of the family Liparidae,” Bulletin of the United States National Museum, vol. 150, pp. 1–204, 1930. View at Google Scholar
  24. J. L. Hart, “Pacific fishes of Canada,” Bulletin of the Fisheries Research Board of Canada, vol. 180, pp. 1–740, 1973. View at Google Scholar
  25. D. L. Stein, “A review of the deepwater Liparidae (Pisces) from the coast of Oregon and adjacent waters,” Occasional Papers of the California Academy of Sciences, vol. 127, pp. 1–55, 1978. View at Google Scholar
  26. K. Kido, “New and rare liparidid species from the Okhotsk and Bering Seas and their adjacent waters,” Japanese Journal of Ichthyology, vol. 29, no. 4, pp. 374–384, 1983. View at Google Scholar
  27. K. Kido, “New and rare species of the genus Careproctus (Liparididae) from the Bering Sea,” Japanese Journal of Ichthyology, vol. 32, no. 1, pp. 6–17, 1985. View at Google Scholar
  28. K. Kido, “Phylogeny of the family Liparididae, with taxonomy of the species found around Japan,” Memoirs of the Faculty of Fisheries, Hokkaido University, vol. 35, no. 2, pp. 125–256, 1988. View at Google Scholar
  29. H. Masuda, K. Amaoka, C. Araga, T. Uyeno, and T. Yoshino, The Fishes of the Japanese Archipelago, Tokai University Press, Tokyo, Japan, 1984.
  30. D. L. Pitruk and V. V. Fedorov, “On validation of the genus Elassodiscus Gilbert et Burke, 1912 (Scorpaeniformes, Liparidae) with description of new species from the Sea of Okhotsk,” Voprosy Ikhtiologii, vol. 33, no. 6, pp. 165–175, 1993 (Russian). View at Google Scholar
  31. D. L. Pitruk and V. V. Fedorov, “Squaloliparis gen. novum (Scorpaeniformes, Liparidae)—new genus liparid fishes from the bathyal of the Sea of Okhotsk,” Voprosy Ikhtiologii, vol. 33, no. 5, pp. 602–608, 1993 (Russian). View at Google Scholar
  32. D. L. Pitruk and V. V. Fedorov, “Allocareproctus gen. novum (Scorpaeniformes, Liparidae)—new genus of liparid fishes from the northwestern Pacific Ocean,” Voprosy Ikhtiologii, vol. 33, no. 1, pp. 16–20, 1993 (Russian). View at Google Scholar
  33. K. Amaoka, K. Nakaya, and M. Yabe, The Fishes of Northern Japan, Kita-Nihon Kaijo Center, Sapporo, Japan, 1995.
  34. A. V. Balushkin, “New genus and species of snailfish Palmoliparis beckeri (Scorpaeniformes, Liparidae) from the northern Kuril Islands with notes on phylogeny of the family,” Voprosy Ikhtiologii, vol. 36, no. 3, pp. 293–299, 1996 (Russian). View at Google Scholar
  35. A. M. Tokranov and A. M. Orlov, “Some biological features of rare snailfish species (Liparidae) in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka,” in Conservation of Biodiversity of Kamchatka and Adjacent Seas, C. G. Korostelev, R. S. Moiseev, A. M. Tokranov, and O. A. Chernyagina, Eds., 2nd Materials Science Conference, pp. 187–190, Kamshat, Petropavlovsk-Kamchatsky, Russia, 2001. View at Google Scholar
  36. N. V. Chernova, D. L. Stein, and A. P. Andriashev, “Family Liparidae Scopoli 1777—snailfishes,” California Academy of Sciences Annotated Checklists of Fishes, vol. 31, pp. 1–72, 2004. View at Google Scholar
  37. C. W. Mecklenburg, T. A. Mecklenburg, and L. K. Thorsteinson, Fishes of Alaska, American Fisheries Society, Bethesda, Md, USA, 2002.
  38. W. E. Barraclough and M. Waldichuk, “Offshore characteristics in the deep waters of the Strait of Georgia as indicated by bathypelagic fish,” Journal of the Fisheries Research Board of Canada, vol. 5, pp. 501–506, 1954. View at Google Scholar
  39. W. A. Clemens and G. V. Wilby, “Fishes of the Pacific Coast of Canada,” Bulletin of the Fisheries Research Board of Canada, vol. 68, pp. 1–343, 1961. View at Google Scholar
  40. C. R. Forrester and R. M. Wilson, “A further record of the blacktail snailfish, Careproctus melanurus Gilbert, from British Columbia,” Journal of the Fisheries Research Board of Canada, vol. 20, pp. 1095–1097, 1963. View at Google Scholar
  41. J. E. Fitch and R. J. Lavenberg, Deep-Water Fishes of California, University of California Press, Berkeley, Calif, USA, 1968.
  42. V. V. Fedorov, “A list of Bering Sea fish,” Izvestiya TINRO, vol. 87, pp. 42–71, 1973 (Russian). View at Google Scholar
  43. A. M. Orlov, “Representatives of Oregonian ichthyofauna off the Asian coasts,” in Commercial and Biological Studies of Fishes in the Pacific Waters of the Kuril Islands and Adjacent Areas of the Okhotsk and Bering Seas in 1992–1998, B. N. Kotenev, Ed., pp. 187–214, VNIRO, Moscow, Russia, 2000. View at Google Scholar
  44. K. Kido and G. Shinohara, “First Record of a liparid fish, Careproctus melanurus (Teleostei, Scorpaeniformes), from Japan,” Bulletin of the National Science Museum, Tokyo A, vol. 23, pp. 127–130, 1997. View at Google Scholar
  45. G. M. Cailliet, A. H. Andrews, W. W. Wakefield, G. Moreno, and K. L. Rhodes, “Fish faunal and habitat analyses using trawls, camera sleds and submersibles in benthic deep-sea habitats off central California,” Oceanologica Acta, vol. 22, no. 6, pp. 579–592, 1999. View at Publisher · View at Google Scholar · View at Scopus
  46. D. Tsutsui and K. Amaoka, “First record of the snail fish, Careproctus simus (Scorpaeniformes: Liparidae), from Japan,” Ichthyological Research, vol. 44, no. 1, pp. 89–91, 1997. View at Google Scholar · View at Scopus
  47. D. A. Somerton and W. Donaldson, “Parasitism of the golden king crab, Lithodes aequispinus, by two species of snailfish, genus Careproctus,” Fishery Bulletin, vol. 96, no. 4, pp. 871–884, 1998. View at Google Scholar · View at Scopus
  48. P. Y. Schmidt, “Fishes of the Sea of Okhotsk,” Trans-Pacific Communications, vol. 6, pp. 1–370, 1950 (Russian). View at Google Scholar
  49. D. L. Pitruk, “Preliminary checklist of species and distribution of fishes of family Liparididae in the Sea of Okhotsk,” Trudy ZIN AN SSSR, vol. 213, pp. 35–45, 1990 (Russian). View at Google Scholar
  50. N. V. Chernova, “Catalogue of type specimens of fishes of the family Liparidae (Scorpaeniformes) in collections of the Zoological Institute RAS,” Voprosy Ikhtiologii, vol. 38, no. 6, pp. 760–775, 1998 (Russian). View at Google Scholar
  51. A. V. Balushkin and V. P. Prirodina, “Second record of Palmoliparis beckeri (Liparidae) off the northern Kuril Islands,” Voprosy Ikhtiologii, vol. 40, no. 1, pp. 97–99, 2000 (Russian). View at Google Scholar
  52. D. S. Jordan and W. F. Thompson, “Record of the fishes obtained in Japan in 1911,” Memoirs of the Carnegie Museum, vol. 4, pp. 205–313, 1914. View at Google Scholar
  53. W. N. Eschmeyer, E. S. Herald, and H. Hamman, A Field Guide to Pacific Coast Fishes, Houghton Mifflin, Boston, Mass, USA, 1983.
  54. D. L. Stein, “Aspects of reproduction of liparid fishes from the continental slope and abyssal plain off Oregon, with notes on growth,” Copeia, vol. 4, pp. 687–699, 1980. View at Google Scholar
  55. A. M. Tokranov, “Size-age composition of snailfishes (Liparidae) in the Pacific waters of southeastern Kamchatka and northern Kuril Islands,” Voprosy Ikhtiologii, vol. 40, no. 3, pp. 347–352, 2000 (Russian). View at Google Scholar
  56. K. D. Carlander, Handbook of Freshwater Fishery Biology, vol. 1, The Iowa State University Press, Ames, Iowa, USA, 1969.
  57. R. S. Zotina and A. I. Zotin, “Quantitative relationships between weight, length, age, egg size, and fecundity in animals,” Zhurnal Obshchei Biologii, vol. 28, no. 1, pp. 82–92, 1967 (Russian). View at Google Scholar
  58. A. M. Orlov, “Diet composition and trophic relations of some non-commercial fishes of the western Bering Sea continental slope,” in Problems of Conservation and Rational Use of Kamchatka Bioresources, A. M. Tokranov and N. A. Chebanov, Eds., Conference Registration Abstract on Science and Practice, pp. 77–78, Goskomkamchatecologiya, Petropavlovsk-Kamchatsky, Russia, 1999. View at Google Scholar