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First record of the sabertooth blenny, Plagiotremus azaleus, in California with notes on its distribution along the Pacific coast of Baja California.

On 8 January 1998, while performing monthly ichthyological transects in King Harbor, Redondo Beach, California (latitude 33[degrees]50.5' N, Longitude 118[degrees]24.0' W), the senior author observed two individual sabertooth blennies, Plagiotremus azaleus, along the inside of the outer breakwater and along the Portofino reef at a depth of 1.5 m (Pondella and Stephens 1994). The water temperatures were 19.8[degrees] and 18.8[degrees]C, respectively. Since the initial sighting, sabertooth blennies were not observed again for another eight months in spite of continual monitoring. After 17 August 1998 they were observed while performing routine transects until 3 February 1999 along the Portofino reef in variable numbers ranging from one to six (Table 1). These fishes were observed in a temperature range from 13[degrees] to 24.5[degrees] C (Table 1). On 18 August 1998, we observed three sabertooth blennies along the Portofino reef and one was captured using a hand net and deposited at the Scripps Institute of Oce anography fish collection (SIO98-263) (Fig. 1). The specimen measured 59.8 mm SL and 68.3 mm TL (Table 2).

The previously reported range of the sabertooth blenny was the lower Gulf of California to Peru and did not include the Pacific coast of Baja California (Thomson, et al. 1979; Allen and Robertson 1994; Grove and Lavenberg 1997). The occurrence of the sabertooth blenny in Santa Monica Bay, represents a substantial range extension of approximately 1450 km. It is not, however, the only siting of this blenny outside of its historic range. It was also reported in a serpulid tube at the center island of Islas Benitos, Baja California, Sur on 5 August 1998 (R. N. Lea pers. comm.). On 4 November 1998 while diving on a cooperative (between CICESE, University of Baja California and University of California, Santa Barbara) research trip, Jennifer Casselle observed and subsequently captured a sabertooth blenny at Chester Rock, Punta Eugenia, Baja California, Sur, (Latitude: 27[degrees] 52.19" N, Longitude: 115[degrees] 2.72" W). On the same expedition another was observed at Point Augustine, Cedros Island (latitude 28[de grees] 4.46" N, longitude 115[degrees] 20.50 W) (D. Schroeder pers. comm.). The specimen at Punta Eugenia measured 59.3mm SL and 70.6 mm TL (SIO00-4) (Table 2). All characters, counts and measures for these two fishes are consistent with those values reported for the sabertooth blenny, considering that this is the only eastern Pacific representative of this group (Smith-Vaniz 1976), identification was straightforward.

The sabertooth blennies of the tribe Nemophini (Perciformes: Blenniidae) represent the most specialized group of the combtooth blennies. The tribe is an intriguing group of marine reef fishes found almost exclusively at tropical and subtropical latitudes to a depth of 25 m. Unlike most blenniids, the sabertooth blennies devote much time to hovering above the substrate or actively swimming in the water column, they have a well-developed swim bladder, which aids in their semipelagic behavior (Smith-Vaniz 1976). Uncommonly large dentary canines used primarily in defense and intraspecific competition characterize Plagiotremus, one of five Nemophini genera. These thin and wedge shaped canines are capable of some movement and are apomorphic along with the lack of both premaxillary canine teeth and a lateral line. With the exception of a single eastern Pacific species, the sabertooth blenny, the tribe is restricted to the Indo-Pacific region.

Originally placed in the genus Runula by Jordan and Bollman (1889), the holotype (USNM 44299) was collected at Indefatigable Island, Galapagos. Much confusion has been noted in the nomenclature of this species, primarily due to the conspicuous color phase shift from a banded juvenile phase to a striped adult phase. Runula azaleus was placed in Plagiotremus by Smith-Vaniz (1976) based upon a single apomorphic character described as "snout of adults fleshy, conical." Smith-Vaniz (1976) included a key to the genera and species of Nemophini and he did recognize Runula as a subgenus of Plagiotremus as five of the 11 species of Plagiotremus, including the sabertooth blenny, share the derived snout shape described above.

SCUBA divers can easily identify the sabertooth blenny and it is especially striking within the temperate reef community. Distinguished by its elongate body, cone-shaped snout, and bright yellow and blue stripes, the sabertooth blenny is easily differentiated from other members of eastern Pacific reef fish communities with the exception of the initial phase of the Cortez rainbow wrasse, Thallasoma lucasanum (Perciformes: Labridae). The sabertooth blenny only superficially resembles the Cortez rainbow wrasse, but differs in lacking the characteristic red underside of the wrasse, being clearly less deep bodied, and having an inferior mouth (rather than terminal).

While sabertooth blennies are known to aggregate with adult Cortez rainbow wrasses, they are not an aggressive mimic of the parasite-cleaning behavior of the juveniles (Hobson 1969). The three types of classical mimicry (Batesian, Mullerian and aggressive), may be found in Plagiotremus as well as in the allied blenniid genera Aspidontus, Ecsenius, and Petroscirtes. The classical example of aggressive mimicry comes from Aspidontus taeniatus, which has both juvenile and adult color phases similar to the labrid Labroides dimidiatus that establishes parasite cleaning stations for larger fishes. This allows A. taeniatus protection so it can approach larger fishes and bite the fins (Randall and Randall 1960). Plagiotremus rhynorhynchos also aggressively mimics this symbiotic cleaner wrasse and will ambush larger fishes on its own biting off pieces of fins, scales and mucous while they are feeding (Randall et al. 1996). This aggressive behavior is what has been observed for P. azaleus which is known to strike larger fishes from below and behind removing dermal material from the startled animal (Hobson 1969). Batesian mimicry may be due to a noxious taste, which has partially been demonstrated for P. townsendi, making them unpalatable to predators (Springer and Smith-Vaniz 1972). There is strong resemblance between the P. laudandus species group and the sympatric species of Meiacanthus, the fangblennies, and this may be an example of Mullerian mimicry (Smith-Vaniz 1976). Thus, this genus is of considerable intrigue in the study of the behavioral evolution of mimicry.

These fishes are diurnal reef species, which shelter within burrows of worm or mollusk tubes on the reef (Hobson 1965). The individuals captured and observed at all locations were adults, as the maximum reported length is 102 mm TL (Hobson 1969; Thomson et al. 1979). Similar to most blennies, the sabertooth blenny is oviparous and deposits its eggs in a parental guarded nest followed by a pelagic larval stage (Watson 1996). There is limited larval data available from the CalCOFI ichthyoplankton surveys, which describe sabertooth blenny larvae only from the Gulf of California and to the south (Watson 1996; H. Geoffrey Moser, pers. comm.). The larvae do have similar preflexion (2.1--5.6 mm), post-flexion (7.2--13.6 mm) and juvenile (26.8--33.0 mm) lengths with respect to the other California blennies and may have a fairly extended larval period. For the southern California blennies the larval period for the mussel blenny, Hypsoblennius jenkinsi, was 34--56 days (mean = 44) and 46--79 days (mean = 66) for the ro ckpool blenny, H. gilberti (Stephens et al. 1970; Ninos 1984). The mussel blenny matures in the laboratory in 141 days after hatching (Stevens and Moser 1982). Considering the life history characters of this and confamilial species (an extended larval period, small size, habitat specificity and early maturity), the northern movement of this species was undoubtedly facilitated by larval drift during the very large 1997--98 El Nino Southern Oscillation event (Chavez et al. 1999). The observance of these fishes over such a wide geographic area and relatively long temporal period suggests that their presence in the warm temperate fauna of the San Diegan Province is not anomalous. However the continued success of the sabertooth blenny in Southern California is unknown.

Acknowledgements

The following research would not have been possible without the assistance of the following persons: John S. Stephens, Jr. of the Vantuna Research Group; Robert N. Lea of the Department of Fish and Game; Donna Schroeder, Jennifer Casselle and Milton Love of the Marine Science Institute, University of California, Santa Barbara; Jorge A. Rosales Casian and Oscar Sosa Nishizaki of CICESE; H. Geoffrey Moser of the National Marine Fisheries Service; the support of Wayne Ishimoto and Chevron Products Company; and the curatorial assistance of Richard H. Rosenblatt, H. J. Walker, and Cindy Klepadlo at the Scripps Institute of Oceanography.

Literature Cited

Allen, G. R. and D. R. Robertson. 1994. Fishes of the tropical eastern Pacific. University of Hawaii Press, Honolulu. xix + 332 p.

Chavez, F. P., P. G. Strutton, G. E. Friederich, R. A. Feely, G. C. Feldman, D. G. Foley, and M. J. McPhaden. 1999. Biological and chemical response of the equatiorial Pacific ocean to the 1997--98 El Nino. Science. 286:2126-2131.

Grove, J. S. and R. J. Lavenberg. 1997. The fishes of the Galapagos Islands. Stanford University Press, Stanford, California. xliv + 863 p.

Hobson, E. G. 1965. Diurnal-nocturnal activity of some inshore fishes in the Gulf of California. Copeia 1965(3):291-302.

-----. 1969. Possible advantages to the blenny Runula azalea aggregating with the wrasse Thalassoma lucasanum in the tropical eastern Pacific. Copeia 1969(1): 19 1-93.

Jordan, D. S. and C. H. Bollman. 1890. Scientific results of explorations by the U. S. Fish Commission steamer Albatross. No. IV. Descriptions of new species of fishes collected at the Galapagos Islands and along the coast of the United States of Colombia, 1887-88. Proc. U. S. Natl. Mus. 12(770):149-83.

Ninos, M. 1984. Settlement and metamorphosis in Hypsoblennius (Pisces, Blenniidae). Ph.D. dissertation, University of Southern California, Los Angeles, 181 p.

Pondella, D. J., II, and J. S. Stephens, Jr. 1994. Factors affecting the abundance of juvenile fish species on a temperate artificial reef. Bull. Mar. Sci. 55(2-3):1216-1223.

Randall, J. E., G. R. Allen, and R. C. Steene. 1996. Fishes of the Great Barrier Reef and Coral Sea. University of Hawaii Press, Honolulu, HI. xx + 557 p.

Randall, J. D. and H. A. Randall. 1960. Examples of mimicry and protective resemblance in tropical marine fishes. Bull. Mar. Sci. Gulf and Carib. l0(4):444-480.

Smith-Vaniz, W. F. 1976. The saber-toothed blennies, tribe Nemophini (Pisces: Blenniidae). Acad. Nat. Sci. Phila. Monog. 19. 196 p.

Springer, V. G. and W. F. Smith-Vaniz. 1972. Mimetic relationships involving fishes of the family Blenniidae. Smithsonian Contributions to Zoology 112. 36 p., 4 figs., 7 pls.

Stephens, Jr., J. S., R. K. Johnson, G. S. Key, and J. E. McCosker. 1970. The comparative ecology of three sympatric species of California blennies of the genus Hypsoblennius Gill (Teleostomi, Blenniidae). Ecological Monographs 40(2):213-233.

Stevens, E. G. and H. G. Moser. 1982. Observations on the early life history of the mussel blenny, Hypsoblennius jenkensi, and the bay blenny, Hypsoblennius gentilis, from specimens reared in the laboratory. Calif. Coop. Ocean. Fish. Inv. Rep. 23:269-275.

Thomson, D. A., L. T. Findley, and A. N. Kerstitch. 1979. Reef fishes of the Sea of Cortez. John Wiley and Sons, New York, New York. xvii + 302 p. + 32 pls.

Watson, W 1996. Blenniidae: combtooth blennies. Pp. 1182-1199 in H. Geoffrey Moser ed., The Early Stages of Fishes in the California Current Region. California Cooperative Oceanic Fisheries Investigations Atlas No. 33., Allen Press, Inc., Lawrence, Kansas. xii + 1505 p.

Accepted for publication 19 June 2000.
Table 1.

Characters, counts and measurement for two specimens of sabertooth
blenny. Plagiotremus azaleus, from southern and Baja California. Lengths
are given in millimeters.

 Specimens
Characters, counts and measurements SIO98-263 SIO00-4

Dorsal Fin VIII, 32 VIII, 33
Anal fin II, 27 II, 26
Pectoral fin 12 12
Procurrent caudal fin rays 6-8 + 6-8 5-6 + 5-7
Pelvic fins present present
Incisors on upper jaw 30 32
Incisors on lower jaw 54 55
Incisor ratio 1.8 1.7
Shape of dentary incisors blunt blunt
Shape of snout conical conical
Snout pigmentation uniform uniform
Interorbital pores 2 2
Supraorbital pores 2 2
Mandibular pores 2 2
Bony spur on innermost anal absent absent
 fin rays
Length of outer lobes of caudal fin elongate elongate
Dorsal fin stripe present present
Standard length 59.8 60.6
Total length 68.3 71.6
Preanal length 25.0 23.7
Caudal fin length 12.7 13.3
Table 2.

Date, number of individuals, temperature, and location of observation
for the sabertoot blenny, Plagiotremus azaleus, outside of the Gulf of
California. OB = outer breakwater, PR = Portofino reefs in King Harbor,
Redondo Beach, CA, as described by Pondella and Stephens (1994).

Date No. individuals Location

January 8, 1998 2 (1) OB, (1) PR
August 5, 1998 1 Islas Benitos, Baja Cal.
August 17, 1998 2 PR
October 29, 1998 3 PR
November 4, 1998 3 Punta Eugenia, Baja Cal.
November, 1998 1 Cedros Island, Baja Cal.
November 19, 1998 3 PR
December 15, 1998 3 PR
January 7, 1999 6 PR
February 3, 1999 3 PR

Date Temperature ([degress]C)

January 8, 1998 19.8, 18.8
August 5, 1998 20.9
August 17, 1998 24.5
October 29, 1998 16.8
November 4, 1998 20.0
November, 1998 19.0
November 19, 1998 16.2
December 15, 1998 13.8
January 7, 1999 14.0
February 3, 1999 13.0
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Author:Pondella, Daniel J. II; Craig, Matthew T.
Publication:Bulletin (Southern California Academy of Sciences)
Article Type:Statistical Data Included
Geographic Code:1U9CA
Date:Dec 1, 2001
Words:2199
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