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Biol. Bull. 209: 146-153. (October 2005)
© 2005 Marine Biological Laboratory

Piscivorous Behavior of a Temperate Cone Snail, Conus californicus

Julia Stewart1 and William F. Gilly2,*

1 Department of Ecology and Evolutionary Biology, University of California Los Angeles, 621 Charles E. Young Dr. South, Los Angeles, California 90095
2 Hopkins Marine Station, Department of Biological Sciences, Stanford University, Pacific Grove, California 93950

* To whom correspondence should be addressed. E-mail: lignje{at}stanford.edu


   Abstract
TOP
 Abstract
Introduction
 Materials and Methods
 Results
 Discussion
 Literature Cited
 
Most of the more than 500 species of predatory marine snails in the genus Conus are tropical or semitropical, and nearly all are thought to be highly selective regarding type of prey. Conus californicus Hinds, 1844, is unusual in that it is endemic to the North American Pacific coast and preys on a large variety of benthic organisms, primarily worms and other molluscs, and also scavenges. We studied the feeding behavior of C. californicus in captivity and found that it regularly killed and consumed live prickleback fishes (Cebidichthys violaceus and Xiphister spp.). Predation involved two behavioral methods similar to those employed by strictly piscivorous relatives. One method utilized stings delivered by radular teeth; the other involved engulfing the prey without stinging. Both methods were commonly used in combination, and individual snails sometimes employed multiple stings to subdue a fish. During the course of the study, snails became aroused by the presence of live fish more quickly, as evidenced by more rapid initiation of hunting behavior. Despite this apparent adaptation, details of prey-capture techniques and effectiveness of stings remained similar over the same period.


   Introduction
TOP
 Abstract
 Introduction
Materials and Methods
 Results
 Discussion
 Literature Cited
 
Conus californicus Hinds, 1844, belongs to a genus of marine gastropods with more than 500 extant species, virtually all of which employ peptide toxins to paralyze prey. Unlike those of most gastropods, the radular teeth of Conus resemble hollow harpoons that serve as hypodermic needles through which toxins are injected by a high-pressure ballistic mechanism (Schulz et al., 2004). These toxins generally target ion channels and receptors in the neuromuscular system and typically show high specificity for particular prey types—other molluscs, worms or fishes, and even certain species within these three groups (see reviews by Olivera, 2002; Terlau and Olivera, 2004). Diversity in the genus, beyond the myriad patterning and coloration of shell, lies largely in prey selection and habitat utilization (Röckel et al., 1995), which in turn are probably constrained by radular tooth morphology (Kohn et al., 1999) and the amino acid sequences of the toxins (Woodward et al., 1990; Duda and Palumbi, 1999; Conticello et al., 2001).

Nearly all Conus species are semitropical or tropical and show a strong, if not obligatory, commitment to one of the three prey types above—worms, molluscs, or fishes (Röckel et al., 1995; Duda et al., 2001). Conus californicus differs in two major respects. First, it is found in the temperate eastern Pacific between San Francisco Bay, California, and Cabo San Lucas, Baja California, Sur, Mexico, where it largely lacks competition from congener species (Hanna and Strong, 1949). Second, its diet is anything but specialized. Natural consumption of at least 56 different organisms has been reported (Kohn, 1966), consistent with predation on a variety of worms and molluscs as well as scavenging of dead octopus and fish (Saunders and Wolfson, 1961). This generalist feeding strategy of C. californicus fits well with its unusually complex radular teeth (Kohn et al., 1999), which have been compared to a Swiss Army knife (A. J. Kohn, 2002, pers. comm. to WFG). At present, little is known of the toxins in C. californicus (Marshall et al., 2002).

In this paper we describe the capture of live fish by C. californicus. In some respects its prey-capture behavior strongly resembles that of strictly piscivorous species such as C. striatus (Kohn, 1956), that retain a grip on the radular tooth after venom injection and pull the fish into the opening proboscis sheath, or rostrum. Another behavior resembles that of piscivorous species such as C. geographus, that capture fish with a gaping rostrum alone, sometimes without prior envenomization (Johnson and Stablum, 1971; Cruz et al., 1978). These two styles of prey-capture behavior have been referred to as "hook-and-line" and "net" fishing, respectively (Olivera, 1997, 2002). C. californicus displays a novel combination of these documented strategies and may utilize multiple stings to subdue a fish. In addition, adaptation occurs over time, so that fish are more readily recognized as viable prey.


   Materials and Methods
TOP
 Abstract
 Introduction
 Materials and Methods
Results
 Discussion
 Literature Cited
 
In June 2003, specimens of Conus californicus (2.0 to 3.6 cm shell length) were collected from Monterey Bay, and 24 snails were divided into groups of 8 and placed in three flow-through seawater aquaria of 20x13x14 cm3, 28x17x16 cm3, and 33x20x19 cm3. The tanks were filled with sand 3–4 cm deep and were covered with hinged plastic-mesh tops to prevent snails from escaping.

The three groups were starved for one week and then exposed for the first time to live juvenile specimens (1.7–3.8 cm length) of the monkey-face prickleback (Cebidichthys violaceus), black prickleback (Xiphister atropurpureus) or rock prickleback (Xiphister mucosus), which were collected from the rocky intertidal at Hopkins Marine Station. One fish was placed in each tank, and the tanks were observed throughout the day but left unobserved overnight. After an incident of presumed fish capture in one tank (the fish disappeared during the night after 4–5 days), each tank was provided with one fish every few days and closely monitored and filmed using a digital video recorder (Sony TRV320). If the fish was not consumed during the period of observation (generally 4–6 hours), it was removed from the tank. Feedings and observations continued in this manner during July 2003 and January 2004. Snails were fed live fish (and nothing else) at least once a week between these periods, but detailed observations were not made.

These experiments generally paralleled preliminary studies in 2001–2002. In the earlier experiments, the snails were placed in one large, sealed, flow-through tank and exposed to a variety of fish, worms, and molluscs. Although the snails preferred the worms and consumed those first, eventually a live fish disappeared from the tank, presumably through predation. At that time, all other potential prey organisms were removed, and only fish were provided thereafter. Piscivorous behavior was then monitored as described above.


   Results
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
Discussion
 Literature Cited
 
Arousal and initiation of hunting behavior: adaptation to fish
When only Conus californicus was in the aquaria, there was little or no visible activity. The snails were mostly buried beneath the sand, with only part of the shell or siphon sticking out. Although some snails crawled around the tank with the siphon extended, in no case was a proboscis ever observed when there was no potential prey in the water. When a live fish was first introduced, naïve snails gave no observable response even though they had been starved for at least one week. Eventually the snails in each tank began to react when a live fish was added by emerging from the sand, increasing locomotion, and extending the proboscis. These activities constitute hunting. As a snail neared a fish, hunting behavior would often intensify, with much probing and extension of the proboscis.

Reaction time to detect prey was measured as the time between addition of a live fish to the tank and the first extension of any snail’s proboscis, an unambiguous indicator of hunting behavior. Snails with short exposure to fish (up to 1 month) generally showed very long reaction times, with a mean of 72.2 min (SD = 85.1, n = 4), although one snail reacted in about 1 min. Snails with long exposure to fish (up to 8 months) displayed hunting behavior after an average of only 2.0 min (SD = 2.3, n = 6). These values are significantly different (Student’s t-test; P < 0.01), which suggests that the mechanisms underlying arousal of hunting behavior become adapted to detecting fish as the duration of exposure to a fish-only diet increases.

Two styles of fish capture
Hunting behavior as described above resulted in 13 filmed attack sequences that culminated in consumption of a fish. Many other attacks were observed but not filmed, and this paper focuses on the 13 documented predation events. Some of these sequences involved more than one attack event, and some involved more than one snail. Details of the sequences are discussed below, but all attacks were of two basic types.

The first event of an attack sequence always involved the injection of a radular tooth by the extended proboscis (i.e., a "sting"), as evidenced by the sudden reaction of the fish. In most cases, the fish was obviously impaled by the tooth held in the proboscis, because the snail attempted to pull the struggling fish into the expanding rostrum. This hunting technique is clearly of the "hook-and-line" variety, although we prefer "sting-and-pull" as a more accurate description of the process.

An example of this behavior is depicted in Figure 1 (see also video clip at http://www.biolbull.org/supplemental/). The sting was delivered three frames (0.099 s) after the time zero panel, and the fish immediately twisted violently, attempting to pull away from the radular tooth for 4 seconds—the 4.44-s panel was the first frame following the sting in which the fish was sufficiently immobile that the digital video image was not blurred. Several additional brief bouts of struggling by the fish ensued, interspersed with attempts by the snail to engulf the fish in the open rostrum (e.g., 9.77-s panel). The fish was finally swallowed headfirst and was half ingested in the 24.94-s panel; only the tail remained exposed less than 2 s later.



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  		Figure 1. Successful sting-and-pull attack by Conus californicus. Video frames (left column) at the indicated times are displayed in chronological order from a continuous clip (underlined 7/23/02 sequence in Fig. 3). Sketches of each frame are displayed in the right column. The white arrowhead points to the tip of the proboscis at the site of the sting near the tail of the fish. The white angle in the 26.57-s panel subtends the tail of the fish just before it was fully ingested. The white arrow in the same panel indicates the exposed proboscis of a buried snail. This fish had been stung twice previously by the same snail. Length of the fish was 2.2 cm. See text for additional details.

 
In four instances a single sting was sufficient to capture the fish, but in most cases the fish managed to break free from the proboscis and temporarily escape. Multiple stings were employed in two additional attack sequences that involved only sting-and-pull events. In the case described in conjunction with Figure 1, three stings were delivered by the same snail (the largest number observed), but in another case observed on the same day six different snails participated with a total of seven stings (7/23/02 attacks in Fig. 3). Successful stings to all parts of the fish were observed, but the posterior end was the most frequently impaled site.



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  		Figure 3. Details of all successful attack sequences observed that ended in consumption of the fish (ordered chronologically). Each bar represents the history of attacks on an individual fish on the indicated date of observation. The attack segments are stacked sequentially, with the final attack on top. Solid black segments indicate sting-and-pull attacks; open bars represent extend-and-engulf attempts. Although no fish was ever captured without being stung, nor was the initial attack ever of the extend-and-engulf variety, this technique was commonly employed and was successful twice. Neither of these events was filmed. Underlined sequences are described in conjunction with Fig. 1 (7/23/02) and Fig. 2 (7/15/03).

 
Sting-and-pull attacks were most often displayed by snails that were crawling on the sand, but two dramatic variations were also observed. Stings were sometimes delivered by a snail completely buried in the sand with only the proboscis emerging, a behavior also reported for C. striatus (Olivera, 2002). In the case illustrated in the 26.57-s panel of Figure 1 (arrow indicates the proboscis), the buried snail was apparently searching for the fish that had just been consumed by the other snail. Snails were also observed to burrow upon coming into proximity of the fish and then attack in this manner from beneath the sand.

In a second type of regularly observed prey-capture behavior, a snail attempted to engulf the fish with the extended rostrum without employing the proboscis to sting. This "extend-and-engulf" tactic thus appears to be analogous to "net fishing" (Olivera, 1997), and in the case of C. californicus, it was always employed after a sting-and-pull attack from which the fish had escaped. Figure 2 (see also online video clip) illustrates an example in which a snail first explored a fish (which it had previously stung several minutes prior to the 0.00-s panel) with its proboscis and then withdrew the proboscis while expanding the rostrum (15.70-s panel) in an attempt to ingest the fish without another sting (18.47-s). In this case, the fish reacted and reversed its heading to point away from the snail (19.37-s). Eventually the fish swam out of the open rostrum, but this took an additional 35 s (panels 28.57 s and 43.63 s). The fish then paused and was captured by a second sting-and-pull attack by the same snail 15 s later (not illustrated).



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  		Figure 2. Unsuccessful extend-and-engulf feeding attempt by Conus californicus. Video frames (left column) at the indicated times are displayed in chronological order from a continuous clip (underlined 7/15/03 sequence in Fig. 3). Sketches of each frame are displayed in the right column. The fish had previously been stung once by the same snail. A subsequent exploration of the fish with the proboscis (0.00–15.7s) was abandoned, and the snail withdrew the proboscis and attempted to engulf the fish in the open rostrum (18.47–28.57s). The fish eventually swam out of the rostrum (43.63 s) but was stung again and consumed shortly thereafter by the same snail. Length of the fish was 1.5 cm.

 
Combination method of fish capture
Over half of the successful attack sequences (7 of 13) utilized the extend-and-engulf method in combination with sting-and-pull, and all but one of these sequences (the one depicted in Fig. 2) involved multiple snails. Figure 3 indicates the type and order of all individual attack events in the seven "combination" sequences. Sting-and-pull attacks are indicated by solid bars; extend-and-engulf attempts are represented by open bars. Extend-and-engulf was the terminal event in only two cases (7/15/03 and 1/10/04), but its overall probability of success (i.e., of being the last attack event before ingestion) was 25% (2 of 8 engulfing attempts), considerably higher than that for sting-and-pull attempts in the same combination sequences (5 of 30 = 16.7%).

In each of the seven instances in which an engulfing attempt was preceded by a sting, the snail attempting to engulf the fish had stung it during the immediately preceding attack. In four of the five cases in which another sting followed a failed engulfing event, the sting was also delivered by the same snail that had attempted the engulfing. These observations indicate that the combination style of prey capture is regularly utilized by individual snails. Use of the extend-and-engulf method by a snail without its previously stinging the fish was observed only once, and this attempt was successful (first 7/15/03 sequence in Fig. 3).

Multiple snails and stings as part of the attack sequence
Although multiple snails participated in most of the observed attack sequences, there did not appear to be any coordinated hunting effort. Many times, however, when one snail inflicted a sting, other snails apparently increased their level of arousal and exploration. It is unclear what signals might be detected in this case, but it appeared that the hunting activity of other snails in some way augmented any chemical scent of the prey itself. Sometimes the snails seemed to become especially aroused after a fish had already been eaten by another snail, at which time a number of snails would pile on top of one another, each with the proboscis extended and probing. This behavior was regularly seen in conjunction with consumption of other gastropod species that were killed by multiple stings when multiple snails were feeding on the same victim (Gilly, unpubl. obs.). In neither of the above two situations did an individual of C. californicus ever sting another of its own kind, despite an extremely high state of arousal.

Most attack sequences directed by C. californicus against fishes also involved more than one sting, and capture of larger fishes required a greater number of stings. Data in Figure 4 are derived from snails that had relatively short experience with fishes ({circ}, up to 1 month) as well as those with prolonged experience (•, up to 8 months). The regression line in Figure 4 is fitted to only the long-term data. Clustering of the short-term data near this line suggests that potency of the venom does not change greatly during exposure to a fish-only diet. We have no way of estimating the quantity of venom injected for individual stings, nor do we know whether the same radular tooth is used more than once if a snail makes multiple sting attempts.



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  		Figure 4. Relationship between fish length and the number of stings delivered before the fish was captured. Larger fish required more stings. Solid circles represent snails with long exposure (1–8 months) to fish; open circles represent snails with short exposure (<1 month). The solid line is a linear regression (r2 = 0.82) to the long-term data only. Only 12 of the 13 total successful attack sequences are included in this analysis, because fish length was not recorded in one case.

 
Effect of stings on fish
Venom of C. californicus appears to cause both immediate behavioral reactions and longer-term debilitation in prickleback fishes. A sting by the snail was almost always immediately followed by a sudden jolting and twisting by the fish, apparently in a vigorous attempt to break away from the proboscis. In several cases that were not part of this study, an escaped fish was removed from the tank and examined under a stereo microscope to search for an embedded radular tooth. Although a wound was generally recognizable, no tooth was ever found (Gilly, unpub. obs.). Thus, an escaping fish appears to break away from the radular tooth and not to pull the tooth free from the proboscis. Although a fish could sometimes recover from such a sting, recovery was not studied in detail.

If the fish succeeded in escaping after an initial sting, it would typically dart to the surface, where it would sometimes swim around the tank in a frenzied manner. Following this bout of activity, the fish typically sank slowly, and when it contacted its normal habitat on the substrate, it would often rapidly swim to the surface before sinking again. This cycle of behavior was generally repeated several times before the fish finally came to rest on to the bottom, where it appeared to be impaired, sometimes lying on its back or side. In some cases the body appeared to be kinked in the midsection. Many times a fish would come to rest in this phase close to the very snail that had stung it, which often elicited another attack.

In attack sequences employing multiple stings, the fish’s reaction progressively lessened as the number of stings increased. Presumably effects of multiple stings are additive and lead to a seriously disabled state in which the body stiffens, and respiration is weak. When in this condition, a fish sometimes did not react at all to an additional sting, and the attacking snail could simply pull the impaled fish into its mouth.


   Discussion
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
Literature Cited
 
Hunting tactics in comparison with other Conus species
This paper is the first account of Conus californicus, a well-known generalist feeder, preying on live fish, and this is the only case of a Conus species that actively hunts, kills, and consumes prey of all three major groups utilized by the genus—worms, molluscs, and fishes. Moreover, C. californicus employs a combination of fish-capture techniques that are similar to two well-documented fish-hunting strategies (Kohn, 1956; Greene and Kohn, 1989; Le Gall et al., 1998): the so-called "hook-and line" and "net" tactics (Olivera, 1997), which we call "sting-and-pull" and "extend-and-engulf," respectively.

Conus californicus will first attempt to sting a fish, but if the fish escapes, the snail will often attempt to engulf the fish without another sting. If this second attempt also fails, another sting-and-pull attack is usually launched. Thus, the extend-and-engulf technique is successfully utilized, but only under particular circumstances. This combination method of fish capture has not been previously described in piscivorous Conus species. Whether this novel method is utilized by C. californicus on living fish in the wild is unclear (Kohn, 1966), but few field observations of prey capture by Conus exist in general.

Although C. californicus displays components of classic piscivorous behavior, its abilities are quite limited in comparison with more specialized fish-hunting species. For example, C. purpurascens never stings more than once before consuming a fish and nearly always stings the fish on the ventral abdomen (Nybakken, 1967). In contrast, C. californicus typically employs multiple stings delivered to different parts of the fish, even after long exposure to a fish-only diet. The radular teeth of C. californicus are much smaller than those of most piscivorous cones (Kohn et al., 1999), and this factor is clearly a disadvantage in holding onto a struggling fish after a sting. In addition, the toxins of strictly piscivorous species are likely to be far more potent than any in C. californicus. Similarly, extend-and-engulf attempts by C. californicus are also rather crude in comparison to species with a specialized rostrum like C. tulipa in which the engulfing behavior is extremely delicate (W. Gilly, unpubl. obs.). Thus, it seems that the apparent inefficiency in fish-hunting by C. californicus reflects specific morphological and pharmacological limitations rather than fundamental behavioral differences.

Some aspects of piscivorous behavior in C. californicus should be considered in light of its generalist nature. Although we are unaware of reports involving multiple sting-and-pull attacks utilized by other piscivorous Conus species in combination with the extend-and-engulf strategy, non-piscivorous Conus species do use a similar combination. Conus imperialis, a vermivore, first stings and releases an amphinomid polychaete and later engulfs it without stinging again (Kohn and Hunter, 2001). A similar behavior occurs with C. brunneus (Gilly, unpubl. obs., and pers. comm. from A. J. Kohn, 2005). Similarly, a number of molluscivorous Conus species sting more than once and later extract the victim from its shell, e.g., C. textile (Schoenberg, 1981; Yoshiba, 1987); C. bandanus (Yoshiba, 1983); C. victoriae (Kohn, 2003); C. pennaceus (Gilly, unpubl. obs.). Thus, C. californicus may simply extend a similar worm- and snail-hunting combination strategy to fish.

Another unusual feature of C. californicus is the involvement of multiple individuals in the killing and consumption of a single prey organism. Multiple snails of this species have been observed contributing multiple stings when attacking large gastropods (Saunders and Wolfson, 1961; Gilly, unpubl. obs.), and we found this same behavior in conjunction with the capture of fish. Several individuals of C. californicus can also simultaneously engulf polychaetes without (or with) stinging them previously (Saunders and Wolfson, 1961; Gilly, unpubl. obs.). In the case of fish hunting, however, C. californicus was never observed attempting to engulf a fish that had not been previously stung. This suggests that although engulfing-without-stinging is a viable strategy for worms, it is not effective with fish. Nonetheless, extend-and-engulf is a prominent and successful component of the combination strategy of fish hunting in C. californicus.

Changes in arousal and prey preference
During the course of this study, snails with longer exposures to fish responded to them more quickly. Naïve snails took days to initiate hunting behavior, but familiarized snails became aroused within minutes. Shorter reaction times—from days to a few minutes—were seen in each of the four tanks studied (a total of about 35 snails). This trend indicates that the snails can adapt to a new prey type over a substantial period of time, and once they do, they are readily aroused by its presence. The reduced response time did not lead to any obvious change in hunting techniques, such as the placement site for a sting (head vs. tail; data not illustrated) or to a change in the apparent potency of individual stings (Fig. 4). To our knowledge, this is the first report of adaptation to live prey by any Conus species.

We also attemped feeding trials with other types of small, intertidal fishes, primarily sculpins (Clinocottus and Oligocottus spp.). Neither naïve nor prickleback-adapted snails ever displayed arousal by these other fishes or consumed them; the potential prey remained apparently untouched for more than 5 days. Whether longer exposure to these other types of fish would also eventually result in predatory activity is unknown. Nonetheless, it seems clear that C. californicus displays preferences for certain types of fish as prey, and the attractiveness of a given type of fish can change over time.

Actions of C. californicus venom on fish
Although little is known about the toxicity of venom in C. californicus (see Marshall et al., 2002), several observations described in this paper suggest the presence of toxins that are active against fish targets. First, larger fish required more stings to be captured than did smaller fish. This dose-dependence suggests that the venom is indeed toxic. Second, the snails never employed the extend-and-engulf tactic to attempt capturing a fish that had not been previously stung. This also suggests that a sting impairs the fish and implies that this disability can be detected by the snail in some way. Third, injection with C. californicus venom as part of an attack causes a violent and quite stereotyped reaction of the fish. The progressive impairment of fish that is seen with multiple stings is also consistent with a dose-dependent phenomenon, and this was especially apparent with larger fish that required more stings.

Although the venom of C. californicus may be toxic to fish, it is unlikely that it contains toxins as potent as those found in purely piscivorous Conus species. Although most of these species are larger than C. californicus and undoubtedly inject larger volumes of venom through much larger radular teeth, even very small specimens of C. catus capture fish with only a single sting (Gilly, unpubl. obs.; see also Schulz et al., 2004).

Evolution of Conus and congeneric competition
Conus californicus has been shown by molecular genetic analyses to be distantly related not only to all of the classic piscivorous species, which form several distinct clades, but probably to all Conus species (Espiritu et al., 2001; Duda et al., 2001; Duda and Kohn, 2005). Because the genetic differences are so great, it is unclear whether C. californicus and its generalist feeding habits represent a primitive condition, or whether they reflect independent evolution in a species largely free of congeneric competition since the upper Miocene (Stanton; 1966). At present, C. californicus overlaps with other Conus species only in the southernmost extreme of its range (Hanna and Strong, 1949).

Even though C. californicus does not show the extreme specializations in behavior, radular tooth morphology, and toxin potency displayed by classic piscivorous Conus species, it contains essential elements from each of these categories, and these features lead to a respectable fish-hunting capability. As discussed above, fish-hunting behavior does not appear to be fundamentally different from worm- or snail-hunting behavior by other more conventional Conus species. What functionally distinguishes the feeding groups must ultimately lie in the toxins used to subdue a particular prey organism and, perhaps more importantly, in the ability to recognize that organism as potential prey. Clearly, C. californicus has the ability to adapt to changes in prey availability, to become more attuned to recognition of a novel prey item, and to then effectively utilize that resource.

Perhaps it is the plasticity behind this ability to adapt, which must involve the central nervous system and probably the osphradium (Spengler and Kohn, 1995), that is unusually robust in C. californicus. Conversely, this plasticity may be much more limited in highly specialized species. No matter how potent a toxin is, it will be useless without prey detection and arousal. This factor merits consideration, along with the complement of peptide toxins, radular tooth anatomy, and competition, as a potentially important feature setting the feeding strategies, and ultimately the evolutionary fate, of C. californicus and other species within the genus.


   Acknowledgments
 
We thank Alex Norton for caring for snails, collecting fish, and providing the sketches of video clips. We are grateful to Dr. Alan. J. Kohn for helpful comments on an earlier version of this paper. This work was supported by a grant from the National Science Foundation (IBN-0131788-002).


   Footnotes
 
Received 8 April 2005; accepted 12 July 2005.


   Literature Cited
TOP
 Abstract
 Introduction
 Materials and Methods
 Results
 Discussion
 Literature Cited
 

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S. M. Salisbury, G. G. Martin, W. M. Kier, and J. R. Schulz
Venom kinematics during prey capture in Conus: the biomechanics of a rapid injection system
J. Exp. Biol., March 1, 2010; 213(5): 673 - 682.
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