THE WASMANN JOURNAL OF BIOLOGY 38{ 1-2). 1980. pp. 1-9 HABITATS AND HABITAT PREFERENCES OF TH E CALCAREOUS SPONGES CLATHRJNA CORIACEA (MONTAGU) AND CLATHRINA BLANCA (MIKLUCHO-MACLA Y) FROM SANTA CATALINA ISLAND, CALIFORNIA

Marion Fischel Johnson

Abstract.-Habitats of two closely related calcareous sponges, Clathrina c:oriac:ea (Montagu) and Clathrina blanca (Miklucho-Maclay), from Santa Catalina Island. California are described. ln submarine caves, C. coriacea grows in areas exposed to greater illu mination and wave action than C. hlanc:a. T he two sponges also occur adjacent to one another at some loca­ tions.

Introduction Species determination in calcareous sponges requires the study of mor­ phology, histology, spicule characteristics, reproduction and habitat pref­ erences (Jones. 1964). A detailed study of Clathrina coriac:ea (Montagu) and Clathrina blanca (Miklucho-Maclay), two closely related calcareous sponges from Santa Catalina Island. California. was under1aken to deter­ mine whether sufficient differences existed to justify separate species names (Johnson, 1976). This paper describes the habitats and habitat preferences of C. c01·icea and C. blanca. Other aspects of their li fe history are sum­ marized elsewhere (Johnson, 1978a, b, c).

Materials and Methods Clathrina c:oriacea and C. blanca were observed at various locations around Santa Catalina Island (Fig. l). SCUBA equi pment was used for all fie ldwork. Weekly or monthly observations were made at Cave D. one of the habitats of the two species. from April 1973 to October 1975. Temper­ ature, relative surge (wave action), and relative turbidity were recorded at the entrance, middle (10.7 m), and back (21 .3 m) of Cave D. Water samples were collected at the three locations for salinity determinations. T he Santa Catalina Marine Biological Laboratory (SCMBL) pier. another study site of the two sponges. was observed from November 1974 to October 1975.

Results ClMhrina coriacea and C. blanca occur in sha llow water on a variety of substrates (Table 1). The habitat preferences of the two species at Cave D and the SCMBL pier are reported in detail. THE WASMA N JOUR AL OF BIOLOGY

West

See Insert Below

0 2 4 6

Sco tt K tlomtttrs

SANTA CATALINA ISLAND

oBtrd Roc~

N t 0 100 200 300 Meters Blue Scale Cavern Point ·:·.·. .· . .. ..

o tsthmus Reef ..

819

Figure I . Map of Santa Catalina Island howing the location of collections of Clnthrina ,·orlacea and C. !J /nn m. VOLUME 38. UMBER 1-2 3

Table I. Habitat of Clathrina coriacea and C. blanca at Santa Catalina Island.

Location Species Substrate Depth (m)

Big Fishermans Cove C. coriacea , Top and under~ide of 3-5 C. blanca roc k ~

Big Fi ~hcrman s Cove C. curiacea Macroc \'Stis ~p. 3 Bird Rock C. curiacea Vertical cliff: on 3-10 Norrisia norrisi Blue Cavern Point Cave C. coriacea . Boulders. noor und 1-8 C. blanca walls Cave D C. coriacea , Boulder . noor and 1-3 C. blanca walls

l s thmu~ Reef C. cnriacea. Boulders: underside 3-8 C. blanca of rocks

Lillie Fi~hermans Cove C. blanca Boulders Rippers Cove C. blanca Boulders 2 SCMBL Pier C. coriacea, On Mytillls ed111is: 0. 1 C. blanca styrofoam Seawater Intake C. curiacea , Bo ulder : pipeline 2-8 C. blanca Ship Rock C. coriacea. Boulders 8 C. blanca South lleadlnnd ave C. coriacea. Walls and ceiling 0.6 C. blanca West End C. coriacea . Boulders 6-10 C. blanca

Cave D, located on the northeast ide of Big Fi hermans Cove, i 24.4 m in length a nd 0.4- 1.8 m in width (Fig. 2). It range from 3.7 m in height at the entrance lo 1.8 m at the back. with the ceiling of the fir t 18.3 m and the Ia. t 3m lying above the ea surface a t low tide (Hur t, 1969). The temperature in the front. middle a nd back of the cave ranged from 12.SOC in January 1974 to 2 l.OPC in Augu t 1974 (Fig. 3A). During mos t of the year the temperature was essentially equal thro ugho ut the cave. The surge (Fig. 38) wa greatest in late a utumn and earl y winter. and again in late spring. It wa greater at the entrance to the cave than in the middle and back. The period of maximum turbidity in Cave D occurred from March to June 1974 (Fig. JC) as a result of increased wave action and plankton blooms. The salin ity (Fig. 30) was relatively constant in 1974, ranging from 33.5 to 33 .7 ppt. It was lowest between February and April 1974 during the period of maximum rainfall at Santa Catalina Island . The salinity was slight- 4 THE WASMAN JOURNAL O F BIOLOGY

CAVE 0 FLOOR DI MENSIONS

Widlh a nd Oiatonce f rom Entranc e •n Meters

t N

-~ . 86-- 18 29

--104 --- 16 76

,\ A._, , ,

Figure 2. Floor dimensions of Cave D. Big Fishennans Cove, showing cave width and distance from the entrance in meters (modified from Hurst. 1969). VOLUME 38. NUMBERS 1-2 5

Table 2. Lllumination (lux) in CaveD, Big Fishermans Cove in August 1%9 (modified from Hurst. 1969).

Distance wuhan cave (m)

0 3. 1 6. 1 9. 1 12.2 15.2 18.3 22.9

Northea~t wall 732-473 164 12 7 4 0 0 0 Southwest wall ')9().603 121 25 6 2 0 0 0

ly higher at the cave entrance than at the back indicating possible fresh­ water seepage. The distribution of C. coriac:ea inside Cave D differs from that of C. blanca. Most C. coriacea are located inside the cave near the entrance on the vertical walls. The zone of maximum density of this specie occurs at 1-3 m on the nonhea t wall. where the illumination mea ured in August 1969 was 164 lux, or approximately 20-70% of the light recorded at the mouth of the cave (Table 2). In late morning and early afternoon the cave wall near the entrance receive direct sunlight. No sponge occur on the outhwe t wall at the entrance as it is completely covered by red and brown algae. Clathrina c:oriacea is rare in the darker pa rt of the cave where the illumination i le than 22 lux. Individual ecn near the back of Cave D are generally ma ll . In CaveD C. blanca is noticeably more abundant than C. coriacea. C/ath­ rina blanca generall y occurs from 5-23 m inside the cave, and is most common between 7 and 14 m where the illumination is less than 7 lu x or approximately 1% of the light at the cave entrance (Table 2). Specimens of C. blanca near the back of Cave D are maller than tho e from the middle of the cave. Thi pecie grows on the vertical wall , on rock , in crevices and beneath mall overhangs in the cave. During the peak growth period of C. blanca. between January and May, it range extend to the cave entrance where it coexi t with C. coriacea. This range extension may be the result of the growth of the brown alga Sargassum muticum and it epiphyte Ach­ enotospora nicholsonii. which obliterate the cave entrance in winter and pring. thereby preventing the penetration of most light into the cave. The SCMBL pier i approximately 100 m southeast of Cave D in Big Fisherman Cove (Fig. 1). The ocean floor i from 3-5 m below the pier. depending on the tide . The water temperature and illumination are similar to that in ide Cave D near the entrance. Most of the float i covered with the mussel Mytilus edulis. The sponges grow on the mussels or directly on the styrofoam blocks attached to the underside of the float. Specimens of C. C'oria cea are much larger and more abundant under the pier than in Cave D. Clathrina blanca. on the other hand, is small er and rarer under the pier than in Cave D. 6 THE WASMANN JOUR ' AL OF BIOLOGY

FRONT A MIDDLE u 0 20 BACK ...a: ::> ...... 18 ...a: a.. 16 ::E ...... a: 14 ...... ~ 12

FRONT 8 5

... 4 1:1a: ::> "'... 3 ...::: .. 2 ..J ...a:

c

)- .... 4 0 Cll a: 3 ....::l ... 2 ...... 2: ...... J a:

FRONT D 33 85 MIDDL E BAC K 3380 ;:: a.. 33 75 a.. 33 70 )- 3365 =?: ....J 3360 "' 33 55 33.50

A s 0 N D J F M A M J J A '73 '74 MONTH VOLUME 38. NUMBERS 1-2 7

Discussion Clcahrina coriacea and C. blanca from Santa Catalina Island are most common in rocky habitats. but also are found attached to mollusc shells, styrofoam, metal and algae. Borojevic ( 1967a), in addition, reported speci­ mens of the two species from sandy habitats. Most representati ves of C. coriacea and C. blanca from Santa Catalina Island occur at depths ranging from a few centimeters below the sea sUJface to 10 m. The two sponges have bee n reported in earlier studies from the intertidal zone to as deep as 40 m (Sar ~t , 1953 ; Boury-Esnault, 1971 ). At Santa Catalina Island C. coria cea is most common in lighter regions of caves near the entrance, and is rare in the darker parts. Labate ( 1964, 1965) also reported this species near the mouth of a cave where there was considerable illumination. The zone of maximum density of C. coriacea is 1-3 m inside Cave D. where the ill umina tion, recorded in August 1969, is 20- 70% of the light at the entrance. Sara ( 196 1a, b , 1964) noted that C. coriacea inhabited parts of caves with a relative light imensity rangi ng from 5- 70% of the light recorded at the surface. Clathrina coriacea is larger and more abundant under the SCMBL pier than in Cave D. Sara ( 1958) also reported that this species grew to a larger size outside a cave in the Bay of Naples. Clathrina blanca, on the other hand, is usuall y seen in darker regions of Cave D and other caves. where the illumination i less than 1% of the light at the cave entrance. rt i rare under the SCMBL pier where there is con­ siderable li ght. Boury-Esnault (1971) and Pouliquen ( 1972) also observed this species in the darker areas of caves. Differences in light preferences also have been recognized between other ·pecies of the genus Clathrina. Sara ( 1961a) observed that in the part of a cave where 2% of the incident light reached the walls 25% of the surface was covered by C. contorta and only 5% by C.falcata . In the darker region of the cave. where only 0.5% of the light reached the cave wall, C. falcata covered 25% of the surface whereas C. contorta covered only 5%. Clathrina coriacea is abundant near the mouth of Cave D where there often is considerable turbulence . Sara (1958, 1959. 1962. 1964) and Labate ( 1964) a lso reported that this species grew best in exposed habitats with

Figure 3. Abiotic data from the front. middle and bac k of Cave D from August 1973 to August 1974. A. Monthly seawater temperature. B. Monthly relative surge ( I =calm ; 5 = o.:xtremely turbulent). C. Monthl y relative turbidity ( I = clear; 4 = very turbid). D. Monthly salinity (salin ity datil for August to January were es tim:~ted by a computer program). When data from the front. middle. and back of Cave Dare identical only n solid line is s hown in the graph. 8 T HE WASMANN JOURNAL OF BIOLOGY strong currents. Clathrina blanca is most common in the middle of Cave D where there is somewhat less turbulence. Sara ( 1958), Borojevic ( 1967b) and Clausade ( 1969) observed this species in sheltered habitats protected from excessive surge. Differe nces in exposure to wave action a lso have been reported between other species of Clathrina. Sara ( 1959) saw C. contort a in areas with li ttle wave action, whereas C. rubra grew in exposed habitats. This study, which reveals differences in habitat preferences between C. coriacea and C. blanca, ill ustrates the importance of investigating various aspects of the life hi stories of c losely related sponges for species determi­ nation.

Acknowledgments I wish to thank Drs. Gerald Bakus and Robert Given for guidance. I also thank Dr. Teresa Audesirk and the many others who helped me wi th the fieldwork.

Literature Cited

Borojevic, R. 1967a. Spongiaires d'Afrique du Sud. II. Calcarea. Transactions of the Royal Society of South Africa, 37: 183- 226. --. 1967b. Importance de !'etude. de Ia repartition ecologique pour Ia taxonomie des eponges calcaires. Helgoliinde.r Wissenschaftliche Meeresuntersuchungen, 15: 11 6-11 9. Boury-Esnault . N. 197 1. Spongiaires de Ia zone rocheuse de Banyuls-sur-Mer. II. Systema­ tique. Vie et Milieu (Serie B), 22:287-349. Clausade. M. 1969. Peuplement animal sessile des petits substrats solids recoltes dans trois biocenoses des fonds detritiques des parages de Marsei lle. Tethys, 1:719- 750. Hurst, W. C. 1969. An ecological survey of Cave D, Big F ishermans Cove, Santa Catalina Island. Unpublished paper. University of Southern California. 55 pp. Johnson. M. F. 1976. Conspecificity in calcareous sponges: Clathrina coriacea (Montagu, 1818 and Clathrina blanca (Mik lucho-Maclay. 1868). Ph.D. dissertation, University of Southern California. 442 pp. - - . 1978a. Significance of life history studies of calcareous sponges for species determi­ nation. Bulletin of Marine Science, 28:570-574. --. 1978b. A comparative study of the external form and skeleton of the calcareous sponges Clathrina coriacea and Clathrina blanca from Santa Catalina Island, California. Canadian Journal of Zoology. 56: 1669- 1677. --. 1978c. Studies on the reproducti ve cycles of the calcareous sponges Clathrina cori­ acea and C. blanca. Marine Biology . 50:73-79. Jones. W . C. 1964. Review of. A Revision of the Classification of the Calcareous Sponges, by M . Burton. Nature (London). 204:416. Labate. M. 1964. Poriferi di grotta superficiale del litoralc adriatico pugliese. Annali dell" lstituto Superiore di Scienze e Leuere di Santa Chiara. 14:319- 342. --. 1965 . Ecologia dei Poriferi della grotta della Regina. Bollettino di Zoologia. 32(1):541- 553. Pouliquen. L. 1972. Les spongiai res des grottes sous-marines de Ia region de Marseille: ecol­ ogic et systematique. Tethys, 3(4):717-758. Sara, M. 1953. Variabiliti1 delle Leucosolcnic del Golfo di Napoli e nuove vedute sulla sis- VOLUME 38, NUMBERS 1-2 9

tematica del gruppo. Annuario dell' lstituto e Mu seo di Zoologia della Universita di Napoli, 5(7): 1-110. ---. 1958. Studio sui Poriferi di una grotta di marea del Golfo di Napoli. Archivio Zoologico Italia no. 43:203-280. ---. 1959. Sulla coesistenza di specie strettamente affini di Poriferi in biotopi litorali. Bollettino di Zoologia, 26 :89-96. - --. 1961 a. Zonazione dei Poriferi nella grotta della ''Gaiola." Annuario dell ' lstituto e Museo di Zoologia della Universita di Napoli . 13: 1-32. ---. 196 lb. La fauna dei Porife ri delle grotte delle isole T remiti. Studio ecologico e sis­ tematico. Archivio Zoologico Italiano, 46: 1-59. --- . 1962. Distribuzione ed ecologia dei Porife ri in acque superficiali del Golfo di Policastro (Mar TiJTeno). Annali dell' lstituto Superiore di Scienze e Lettere di Santa Chiara, 12:191-215. - - - . 1964. Distribuzione ed ecologia dei Poriferi in acque superficiali della Riviera ligure di Levante. Archivio Zoologico Italiano , 49:1 81-248.

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