Ballona Institute Marine Biology Publication


SELECTED EXCERPTS
From
ASCIDIANS OF THE LITTORAL ZONE OF
SOUTHERN CALIFORNIA
By
William Emerson Ritter and Ruth Agnes Forsyth
(Contribution from the Scripps Institution for Biological Research)
August 17, 1917

California State Bear Flag

Compiled - Edited - Written
By
Robert Jan 'Roy' van de Hoek
Ecologist, Conservation Biologist, Marine Biologist, Environmental Biologist, Wetland Scientist, Environmental Historian, Biographer, Geographer
Ballona Institute
322 Culver Boulevard
Los Angeles, CA 90293

www.ballonainstitute.org

October 17, 2008

The aim of this paper is mainly to contribute to the knowledge of the ascidian fauna of the California coast south of Point Conception. ... More exhaustive collecting, particularly on the Santa Barbara Islands and the opposite mainland, will undoubtedly bring to light many species which we now know only from northern localities, where much more collecting has been done than anywhere south of the Point excepting the San Pedro and San Diego regions.

The two lists here given of species, with the families to which they belong, include all the ascidians of the southern California littoral zone known to science, and also those not yet known from the littoral, but occurring off shore in depths of water so shallow that they may be expected to be found on shore.

LIST OF SPECIES
1. Molgula verrucifera, n. sp.
2. Halocynthia johnsoni Ritt.
3. Styela montereyensis (Dall)
4. Styela montereyensis (Dall)
5. Styela gibbsii (Stimpson)
6. Styela barnharti, n. sp.
7. Ascidia californica, n. sp.
8. Cheylosoma productum (Stimpson)
9. Ciona intestinalis (Linnaeus)
10. Metandrocarpa dura (Ritter)
11. Metandrocarpa michaelseni, n. sp.
12. Polyzoa translucida, n. sp.
13. Botryllus tuberatus, n. sp.
25.
26. Amaroucium californicum, n. sp.
27. Amaroucium solidum, n. sp.
28. Amaroucium aequali-siphonis
29. Euherdmania claviformis Ritt.

To be added to these without much doubt, because known from depths of 50 fathoms and less are:
1. Halocynthia okai Ritt. (Known in depth of 10-80 fathoms. Ritter, 1907.)
2. Microcosmus transversus Ritt. (Known in 33 fathoms. Ritter, 1907.)
3. Boltenia echinata Ritt. (Known in 21 fathoms. Ritter, 1907.)
4. Styela hemicaespitosa Ritt. (Known in 29 fathoms. Ritter, 1913.)
5. Ascidia (Phallusia) vermiformis Ritt. (Known in 30 fathoms. Ritter, 1913.)
6. Psammaplidium spauldingi Ritt. (Known in 33 fathoms. Ritter 1913.)
7. Trididemnum (Didemnum) opacum Ritt. (Known in 33 fathoms. Ritter, 1913.)

Search for these seven species in the littoral zone will be among the interesting motives of future ascidian collecting.


DESCRIPTION OF SPECIES

Molgula verrucifera, n.sp.
Plate 38, figure 5; plate 40, figures 15-20
Habitat and distribution. - On the exposed surfaces of rocks usually, but sometimes on the under surfaces, in the littoral zone, La Jolla, California. M. verrucifera undoubtedly occurs at other places than La Jolla but has not yet collected elsewhere.

The specific name has reference to the wart-like appearance of the siphons even in preserved specimens.

Halocynthia johnsoni Ritter, 1909
A striking thing about this species is its great abundance in San Diego Bay, and the large size reached there by the individuals, as compared with what one finds on the open shores. Its favorite habitat appears to be the piles of wharfs where, at times, it makes almost a solid coating. Although it must be counted as a native of the whole littoral zone, we have found only occasional small specimens at outside points.

Mention may be made of the fact that before San Pedro Bay was completely dredged to make it a harbor, H. johnsoni occurred there in the shoaler waters in enormous numbers on the bottom, associated with several species of lamellibranch molluscs.

Styela montereyensis (Dall)
Plate 38, figure 1; plate 41, figures 28-34
Cynthia (?) montereyensis, Dall, 1871, page 157.
Although Styela montereyensis was, so far as we know, the first ascidian ever described from the California coast, and though it has been studied more, probably, than any other, because of the meagreness of the original description we describe it fully as though it were a new species.

Habitat and distribution. - The littoral zone from British Columbia at the north to the southern limit of the United States at the south, according to present knowledge.

That this, one of the earliet known and most familiar ascidian species of Pacific North America, should have remained to this time without a detailed description is one of the vicissitudes in the progress of knowledge of our local marine fauna.

It is noteworthy that this species, like several other ascidians, seems to flourish much better on the piles and other similar objects introduced into the water than on the natural shore rocks. The senior author has collected S. montereyensis from many points on the coast from San Diego to Mendocino, but has never seen a specimen of anything like maximum size growing on native rocks. The largest individuals seen were on the piles of the wharf at Santa Barbara; and at no other point has it been found in such abundance as there. However, it occurs in abundance and large size on the wharf's and breakwaters in the vicinity of Los Angeles.

Styela gibbsii (Stimpson)
Cynthia gibbsii, Stimpson, 1864, page 159.
This is one of the most widely distributed ascidians of the west coast of North America, it being now recorded from British Columbia to San Diego, and from the littoral zone to a depth of forty fathoms. On the coast of southern California it appears to be rare along shore, but fairly common down to a depth of forty to fifty fathoms.

Styela barnharti n. sp.
Plate 38, figure 2; plate 42, figure 39 and 40
One large specimen of this species was taken in July, 1915, from piles in San Diego Bay. Two small specimens were found in February on the carapace of a crab, Rhodea parvafrons, taken at the end of the wharf of the Scripps Institution.

Styela barnharti belongs to the comparatively small section of the genus which have more than five gonads on one side. Its nearest of kin seems to be S. elsa Hartmeyer of the Japanese waters.

We take great pleasure in naming this interesting Sty[el]a for Mr. P. H. Barnhart, curator of the Scripps Institution, to who we are indebted for all the specimens so far seen.

Ciona intestinalis (Linnaeus)
Ascidia intestinalis, Linn., 1767, page 1087, no. 3.
We have subjected specimens from San Diego Bay to a thorough-going comparison with the descriptions and figures of Mediterranean specimens given by M. Roule in his well-known monograph of 1884, and find nothing to suggest even a race distinction for the west American animals. Indeed, the perfect identity and the fact that the species appears to be distributionally restricted in this region almost entirely to localities frequented by ships, leads one to wonder if it is not an immigrant to these parts. This surmise is the more warranted by the habits of the animal, it being especially given to clinging to the under sides of floats, buoys, and the like. In these situations it flourishes most luxuriantly and occurs in enormous numbers. We would not however, make too much of this suggestion as to distribution, since the species has been reported (Huntsman, 1911, and Ritter, 1913) from a rather wide range in Pacific waters than is altogether consistent with this theory. Ciona is sexually ripe in San Diego Bay through the later summer, the entire autumn, and to mid-winter at least; probably ripe animals may be found throughout the year.

Metandrocarpa dura (Ritter)
Goodsiria dura, Ritter, 1896, page 150.
Metandrocarpa dura, Michaelson, 1904, page 70.
Although this species is not very often taken in its original habitat, it is still one of the most conspicuous of our ascidians - this from its favorite habit of forming incrusting masses on various of the larger seaweeds, which, though usually growing below tide, are often washed up decorated with the bright red colonies.

Polyzoa translucida n. sp.
Plate 38, figure 7; plate 42, figures 36 to 38
Habitat and distribution. - So far as known, only from wharf piles in San Diego Bay where it occurs interwoven with hydroids and other animals which inhabit the piles. The only specimens were taken in June.

Amaroucium californicum n. sp.
Plate 46, figure 72
This species has been referred to several times in papers by the senior author as a MS. species by Ritter; but in the absence of a diagnosis or a figure hitherto published, from now on it should be assigned to Ritter and Forsyth.

Habitat and distribution. - A. californicum is probably the most common ascidian on the California coast. It occurs on rocks, usually on the under sides, at all points where collecting has been done, and is found everywhere on piles, floats, breakwaters, etc., except in the upper portions of bays where the density and temperature of the water are distinctly different from normal sea water. Dredgings do not indicate that it flourishes in depths beyond a very few fathoms. It also occurs at Puget Sound (Ritter, 1900), and, with some doubt, on the Alaskan coast as far to the north and west as the Shumagin Islands (Ritter, 1901).

Type locality. - San Diego.

Its closest relative appears to be A. glabrum Verrill of the north Atlantic coast of North America.

Amaroucium solidum, n. sp.
Plate 46, figures 69 and 70
Habitat and distribution. - The only localities from which specimens have been certainly identified as belonging to A. solidum are San Diego Bay and Santa Monica, where they were taken from piles in both localities.

Amaroucium aequali-siphonis, n. sp.
Plate 38, figure 4; plate 45, figure 61
Habitat and distribution. - So far the species has been taken only at Rincon Point, Santa Barbara, California. It belongs to the littoral zone alone, as far as we know.

Euherdmania claviformis (Ritter)
Herdmania claviformis, Ritter, 1903, page 237.
Euherdmania claviformis, Ritter, 1904, page 650.
Euherdmania claviformis, Hartmeyer, 1909, page 1470.
This is one of the abundant ascidians on the southern as well as on the central and northern California coast. In the vicinity of La Jolla, for example, it is found in great abundance on the under side of rocks at low tide. Apparently it is confined to the littoral zone.

CONCLUSION
by
Robert Roy van de Hoek
Marine Biologist
Ballona Institute
The research that I conducted into the "life and times" of Ruth Agnes Forsyth has brought to light from the dim past of history via the biographical notes of Miss Forsyth a unique observation that is invaluable for ecological restoration and conseration biology of marine life at San Pedro with implications for Ballona as well. In essence, she and Dr. Ritter showed us that the ascidian (sea squirt or tunicate) then known as H. johnsoni, occurred together with many species of clams (Lamellibranch) in a healthy and unique assemblage of biodiversity only 90 years ago. This community as Miss Forsyth described it at San Pedro gives us a baseline as well as goal for genuine and truthful and honest restoration at San Pedro and Ballona.

Notes Toward a Biography Ruth Agnes Forsyth


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