PANDALUS GURNEYI STIMPSON SYNONYMIZED with PANDALUS DANAE STIMPSON (DECAPODA: PANDALIDAE) Mary K
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18 December 1991 PROC. BIOL. SOC. WASH. 104(4), 1991, pp. 812-815 PANDALUS GURNEYI STIMPSON SYNONYMIZED WITH PANDALUS DANAE STIMPSON (DECAPODA: PANDALIDAE) Mary K. Wicksten Abstract. —Pandalus gurneyi Stimpson, 1871 is found to be a junior synonym of P. danae Stimpson, 1857. In all features that are supposed to distinguish between the two (number of rostral spines and teeth, length of rostrum/length of carapace, number of carpal articles of the second pereopods, length of scapho- cerite/length of rostrum, and length/width of the sixth abdominal segment), there is considerable variability between individuals throughout the range. Specimens from southern California and Baja California tend to have fewer dorsal rostral spines, more ventral rostral teeth and fewer carpal articles than specimens from north of Point Conception, California. Small animals and functional males tend to have proportionally longer rostra than large females. Pandalus gurneyi may have been described from a male of P. danae. The coonstripe shrimp, Pandalus danae 1.5-1.66 times longer than the carapace, Stimpson, 1857 is one of the most strikingly with 8-9 median dorsal movable spines and colored shrimp of low intertidal and shallow 9-10 immovable ventral spines. The right subtidal regions in Washington and British second pereopod had 17 carpal segments Columbia, on the northwestern coast of and the left, the longer of the two, 45 carpal North America. The animal is marked with segments. The sixth abdominal segment was brown spots and stripes on a translucent 1.5 times as long as wide. (Schmitt used the background, with exceptionally vivid band- terms "spines" and "segments" as quoted ing on the antennae and pereopods. Butler here, although later authors have called im- (1980) provided a more detailed descrip- movable spines "teeth" and carpal seg- tion, color notes and illustration of the spe- ments "carpal articles"). Stimpson's origi- cies. Ricketts et al. (1985) provided natural nal description noted that the shrimp was history notes on the shrimp, as did Kozloff "large" and that the "feet of the third pair (1973), who also included a black-and-white . terminate in well-formed, subcheliform photograph. The popular books by Cribb hands." (1983) and Rotman & Allen (1983) included According to Schmitt, P. gurneyi ranged color close-up photographs of the species. from Monterey to San Pedro and Santa Cat- Stimpson (1871) also described a second alina Island, California, at 17-101 m, while species, Pandalus gurneyi. The description P. danae ranged from Sitka, Alaska to San consisted of a brief paragraph which stated Francisco, California, at 18-186 m. How- that the species had a rostrum "more than ever, Butler (1980) gave the range of P. da- one-half longer than the carapace" and nae south to Point Loma, California, from armed above with 8-9 "teeth" and 9 ventral the intertidal zone to 185 m. There has been "teeth." Schmitt (1921) noted that the spe- little mention of P. gurneyi in recent years cies was "very near P. danae,'''' and that it except for inclusion in species lists or re- differed from P. danae in having a rostrum gional guides (Word & Charwat 1976, VOLUME 104, NUMBER 4 813 Wicksten 1980), but Pandalus danae has rostrum to carapace length, length versus been trawled off northern California (Wick- width of the sixth abdominal segment, the sten 1984). number of rostral spines and their place- Recently, members of the Underwater ment, the length of the antennal scale and Photographic Society (Los Angeles and the lengths and number of carpal articles of Northern California Chapters) photo- the second pereopod were reported and graphed pandalid shrimp in shallow inter- compared to determine whether there were tidal areas from Monterey Bay south to the any consistent differences between species. coast of Los Angeles and the nearby islands Published photographs were examined to of southern Caifornia. I photographed and determine if there were any consistent dif- collected some of these pandalid shrimp in ferences in color between shrimp from Monterey Bay, near Pacific Grove, and ob- Washington and British Columbia versus served them off the Palos Verdes Peninsula, those from California. Color slides were California. These animals differed in their taken by photographers Philip Turner of El color pattern slightly from that previously off Pacific Grove and at the Monterey Bay described for P. danae in that their stripes Aquarium and Seattle Aquarium. Slides were not chocolate brown, but brick red. taken by photographers Philip Turner of El Their pereopods had bright yellow bands as Cajon and Ken Howard of San Anselmo, well as brown and white ones, and the body California were examined. bore bright blue spots as well as stripes of brown or white. However, Butler (1980) Results noted variation in the color pattern of P. In all features that are supposed to dif- danae, including these color marks. ferentiate P. gurneyi from P. danae, there Do these shrimp from California belong is considerable overlap. Numbers of dorsal to one or two species of Pandalus? I un- and ventral rostral teeth, rostrum/carapace dertook this study to determine which spe- length ratios, length/width ratios of the sixth cies were present, and whether or not there abdominal segment, and numbers of carpal were consistent differences in color, mor- articles, are presented in Table 1. In the phology, range or habitat that could be used table, north-central California is defined as to distinguish between P. danae and P. gur- between the Oregon border and Point Con- neyi. ception; southern California is the coast south of Point Conception. There is consid- Methods erable overlap in characters from area to I examined 103 specimens previously area and between the figures reported for P. identified as P. danae or P. gurneyi, from danae and P. gurneyi. As a general rule, the localities ranging from Puget Sound, Wash- northernmost specimens had more dorsal ington to Bahia San Quintin, Mexico. Spec- rostral teeth, southern ones had more ven- imens were from the collections of the Allan tral teeth; and northern ones had more car- Hancock Foundation, University of pal articles than those to the south. Only a Southern California (AHF); National Mu- few animals had unusually high numbers of seum of Natural History (Smithsonian In- rostral spines or teeth: a single large female stitution), and Scripps Institution of Ocean- had 16 dorsal spines, and three specimens ography. Stimpson's type specimens no had 10 ventral teeth. longer are in existence (presumably they Small animals from southern California were lost during the Chicago fire of 1871). had the most variable form of rostrum. The However, I was able to examine specimens shape ranged from nearly straight to strong- identified by W. L. Schmitt. The ratio of ly upcurved; the length, from less than the 814 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON Table 1 —Comparison of specimens of Pandalus danae by locality. North-Central Southern California- Washington-Oregon California Mexico Number of dorsal rostral spines 9-13 7-16 7-11 Number of ventral rostral teeth 5-7 5-8 6-10 Average rostral formula 11/6 10/6 9/8 Rostrum/carapace 0.9-1.2 1.0-1.1 0.7-1.7 Length/width of sixth abdominal segment 1.6-2.0 1.2-1.6 1.1-2.0 Number of carpal articles of left second pe- reopod 57-67 55-60 47-59 Number of carpal articles of right second pereopods 22-27 18-21 15-23 carapace to twice its length. Small animals son, 1857 should take priority over P. gur- tended to have relatively larger rostral spines neyi Stimpson, 1871. Holthuis (1980) noted spaced more widely apart than larger ani- that P. franciscorum Kingsley, 1878 also is mals. However, animals with long, up- a synonym of P. danae. In describing P. curved rostra were found in the same sam- gurneyi as a distinct species, Stimpson prob- ples as others with straight and shorter ably was not aware that pandalid shrimp rostra, indicating that this variability was are protandrous hermaphrodites. Schmitt due to individual or age-related differences (1921) also may have been unaware that rather than to genetic or habitat-induced Pandalus species are sexually dimorphic, causes. Smaller animals also tended to have because hermaphrodism in P. danae was relatively longer antennal scales (scapho- first described by Berkeley (1929). Butler cerites), as long as the carapace, but the ratio (1980) noted that in male carideans, the ros- of the length of the antennal scale to the trum generally is longer in proportion to the carapace length varied from 0.7-1.0 body than in females. In protandrous her- throughout the range of P. danae. maphrodites, males also are smaller than As a general rule, coonstriped shrimp from females. It is noteworthy that two of Puget Sound and British Columbian waters Schmitt's specimens of P. gurneyi are func- had bands of dark chocolate brown on the tional males, with characteristic prehensile body and appendages, and only white or dactyls of the third pereopods (Butler 1980, translucent bands on the appendages. fig. 4C) and flap-like endopods of the first Shrimp from Monterey Bay and farther pleopods. Stimpson's mention of "subcheli- south tended to have brick red bands and form hands of the third pair of legs" suggests bands of bright yellow on the appendages, that he also examined a male, although he as well as a few bright turquoise blue spots did not indicate the sex of the specimen. on the body. However, some larger indi- Differences in the numbers of rostral teeth viduals from Monterey Bay were translu- and proportions of the body in P.