Frogspawn Coral

Identity and scope

Common Name: Frogspawn Coral

Scientific Name: Fimbriaphyllia divisa and Fimbriaphyllia paradivisa (formerly Euphyllia divisa and Euphyllia paradivisa)

Other Names: Octopus Coral; Grape Coral; Honey Coral; Wall Frogspawn; Branching Frogspawn

Family: Euphylliidae

Coral Type: Large-polyp stony coral (LPS); available in wall and branching growth forms

Native Range: Tropical Indo-Pacific, including the central and western Pacific, Southeast Asia, northern Australia, and portions of the Indian Ocean

Overview

General Description: Frogspawn Coral is a fleshy LPS coral named for tentacle tips that resemble clusters of frog eggs. The aquarium trade name includes both wall-form Fimbriaphyllia divisa and branching Fimbriaphyllia paradivisa. Both rely heavily on photosynthesis, benefit from stable reef chemistry, and need enough room to expand without touching neighbors.

Appearance: Large polyps extend from a hard calcium-carbonate skeleton. Each tentacle divides near its tip into several rounded, oval, or anchor-like lobes, creating the characteristic frogspawn appearance.

Color Variations: Common colors include green, cream, tan, brown, yellow, purple, pink, and multicolored combinations with contrasting tips. Colorful trade names do not necessarily represent distinct species or stable genetic lines.

Growth Form: F. divisa forms a continuous or meandering wall skeleton, while F. paradivisa develops separate branching heads.

Notable Characteristics: Frogspawn resembles Hammer Coral, but its tentacle tips usually divide into multiple rounded lobes rather than forming a single hammer- or anchor-shaped end. Identification matters because wall and branching forms differ in fragging risk.

Natural Habitat

Native Distribution: Widely distributed across tropical Indo-Pacific reefs, with exact ranges differing between the wall and branching species

Natural Reef Habitat: Typically associated with protected reef slopes, lagoons, and other sheltered habitats where sediment may be present and water movement is not extreme

Depth: Generally shallow to moderate reef depths; recorded depth varies by species and locality

Natural Lighting: Exposure varies with identified species, locality, depth and water clarity. Natural-habitat descriptions are context, not a measured aquarium PAR prescription.

Natural Flow: Exposure varies by species, locality and reef position. A natural-flow description does not determine a universal aquarium pump setting.

Other Habitat Notes: The name Frogspawn Coral covers more than one species, so published habitat and depth records should be matched to the confirmed scientific identity when possible.

Aquarium Placement

Recommended Placement: Start on the sandbed or lower reef during acclimation, then place on lower to middle rockwork if the coral remains expanded and its measured PAR is appropriate.

Space Requirements: Allow room for full polyp inflation, nighttime extension, and future skeletal growth.

Rock/Sand Placement: Mount securely on rockwork or a stable coral holder above the sand. Keep fleshy tissue from rubbing against rock or being buried by shifting substrate.

Attachment Method: Secure the exposed skeletal base with reef-safe cyanoacrylate gel, epoxy putty, or a stable coral mount; never apply adhesive to living tissue.

Orientation: Orient the colony so every polyp can inflate freely. Give wall colonies extra protection because damage to one area can spread along their continuous tissue.

Distance From Other Corals: Leave clearance beyond the fully expanded colony and any observed defensive reach, including after dark and down-current. Add room for growth and neighboring aggression; no fixed separation guarantees compatibility.

Other Placement Notes: Avoid narrow crevices that pinch tissue. Check expansion after lights-out before deciding that the original spacing is sufficient.

Lighting

Lighting Requirement: Establish the identified form's previous lighting. Neither a generic low/medium light graphic nor trade color establishes a universal requirement.

PAR Range: Tidal Gardens discusses varied light responses but its generic PAR illustration is not a verified range for every wall or branching Frogspawn. Match initial measured lighting to the seller's history, then change gradually with tissue, color and expansion observations.

Spectrum Considerations: Ask about the seller's previous spectrum, measured intensity and photoperiod. Use appropriate reef lighting and make gradual changes; blue appearance, fluorescence or a color setting alone does not verify sufficient or safe exposure.

Acclimation Requirements: Ask about previous measured PAR, spectrum and photoperiod. Change exposure gradually with an adjustable fixture, shading or position, observing tissue and colony response; no fixed acclimation deadline guarantees success.

Signs of Too Much Light: Paling, bleaching, contraction or tissue deterioration after increased exposure warrant a lighting review, but are not light-specific diagnoses. Check water conditions, flow, physical injury, pests and contact damage before making repeated changes.

Signs of Too Little Light: Reduced growth or altered color can prompt a review of measured exposure and shading, but also has other causes. Compare with the colony's previous conditions and check chemistry, nutrition, flow and tissue condition rather than increasing light from appearance alone.

Water Flow

Flow Requirement: Tidal Gardens describes moderate-to-strong flow, differing from the former low-to-moderate label. Resolve this with the specimen's previous conditions and broad adjustable movement: clear debris without pinning tentacles, collapsing expansion or abrading flesh. Do not impose one category on both forms.

Preferred Flow Pattern: Provide adjustable broad indirect movement that clears debris and reaches the whole colony without pinning, abrading or tearing tissue. Reassess as the colony grows; qualitative flow categories are not universal pump settings.

Signs of Excessive Flow: Direct mechanical bending, tissue abrasion or continuous pinning warrants less direct exposure. Retraction or tissue loss alone is nonspecific; assess measured conditions and other possible irritants.

Signs of Insufficient Flow: Persistent debris or retained mucus warrants a circulation review. Poor expansion, color change or tissue decline has other possible causes and does not by itself prove inadequate flow.

Water Parameters

Temperature: OATA's large-polyp stony coral aquarium guide gives 24-26 degrees C as broad aquarium context, not a verified temperature optimum or tolerance limit for the identified Frogspawn specimen. Maintain stable measured conditions, ask about the specimen's history and adjust gradually.

Salinity: OATA's marine-and-invertebrate aquarium example is 1.024-1.026 specific gravity: reef-system planning context, not a verified salinity optimum for the identified Frogspawn specimen. Match established conditions with a calibrated instrument and check its temperature basis; no fixed SG-to-ppt conversion is assumed.

pH: OATA's large-polyp stony coral aquarium guide lists pH 8.1-8.3 as broad aquarium context, not a verified specimen limit for the identified Frogspawn specimen. Its general marine setup sheet uses a different pH interval. Monitor pH with gas exchange and carbonate alkalinity; avoid abrupt corrections to force a number.

Alkalinity: OATA's large-polyp stony coral aquarium guide lists 8-12 dKH as broad aquarium context, not a required endpoint or dosing target for the identified Frogspawn specimen. Measure carbonate alkalinity, keep changes gradual and consider nutrient conditions and observed response. dKH is not pH or freshwater GH.

Calcium: OATA's large-polyp stony coral aquarium guide lists 380-450 ppm calcium as broad aquarium context, not proof of a specimen-specific optimum or dosing requirement for the identified Frogspawn specimen. Check actual system demand and measured trends before adjusting supplements.

Magnesium: OATA's large-polyp stony coral aquarium guide lists 1250-1350 ppm magnesium as broad aquarium context, not a verified specimen-specific optimum or automatic dosing instruction for the identified Frogspawn specimen. Measure system conditions and verify any need before gradual adjustment.

Nitrate: Track nitrate with a reliable test alongside feeding, filtration and coral response. Avoid uncontrolled accumulation or abrupt nutrient stripping; no common optimal interval or diagnosis from one reading is established for every specimen in this guide.

Phosphate: Track phosphate, food input, algae and specimen response together. Avoid uncontrolled accumulation and abrupt stripping; a single low or high reading does not establish the cause of tissue loss, and no universal specimen-wide interval is prescribed.

Other Relevant Parameters: Use appropriate marine source water and routine system monitoring. Investigate ammonia or other abnormal readings rather than assuming a trace-element deficiency. Supplement only for a verified system need with suitable testing and product instructions; freshwater GH targets are inapplicable.

Parameter Sensitivity: Abrupt changes and tissue injury warrant attention. Tidal Gardens reports greater difficulty with wall forms, but that observation is not a guaranteed prognosis for every colony.

Stability Requirements: Favor consistent measured marine conditions over repeated corrections. Verify surprising results, consider recent feeding, dosing and equipment changes, and adjust deliberately rather than changing chemistry, light and flow together.

Feeding & Nutrition

Photosynthetic: Yes; it hosts photosynthetic zooxanthellae

Natural Feeding: Receives energy from light and captures zooplankton, suspended organic matter, and small food particles with its tentacles

Target Feeding: Tidal Gardens describes optional direct feeding with variable acceptance in its stock. Offer only small suitable food when the specimen responds, monitor uneaten food and nutrients, and do not force-feed a stressed colony.

Recommended Foods: Finely chopped mysis shrimp, enriched brine shrimp, copepods, small marine plankton preparations, or quality coral foods sized for the polyp

Feeding Frequency: No fixed schedule is established across the stated scope. If supplemental feeding is used, adjust small amounts to actual acceptance, uneaten food and measured nutrient trends; do not force-feed a stressed colony.

Benefits of Feeding: Grower observations can support optional feeding in their own stock, not a guaranteed improvement in growth, color or recovery for every specimen. Feeding does not substitute for appropriate lighting, measured water quality or health assessment.

Special Nutritional Requirements: Do not overfeed. Stable nutrients and balanced reef chemistry are more important than heavy supplemental feeding.

Growth

Growth Rate: No uniform rate is established across wall and branching forms. Monitor the actual colony rather than predicting head addition or expansion on a schedule.

Growth Pattern: Branching Frogspawn adds and divides individual heads; wall Frogspawn expands along a continuous meandering skeleton.

Maximum Colony Size: No common aquarium maximum is established for both forms. Reserve room for skeletal growth, full expansion and the colony's observed defensive reach.

Space Requirements: Plan for skeletal growth, broad polyp inflation, and a defensive buffer around the colony.

Overgrowth Concerns: It is not normally invasive, but expanding polyps can shade or sting neighbors, and mature colonies may outgrow their original placement.

Aggression

Aggression Level: Moderate to high

Sweeper Tentacles: Yes. Extended feeding or defensive tentacles can reach several inches beyond the skeleton, particularly at night.

Chemical Warfare: A dissolved-compound interaction is possible in a mixed reef, but this review does not establish a predictable chemical effect for every specimen or a guaranteed filtration remedy. Examine physical contact, shading and water conditions before attributing decline to chemical warfare.

Stinging Ability: Prevent contact with neighbors and assess the actual defensive reach. No fixed sting-strength grade establishes safe proximity or guarantees tolerance between colonies.

Required Spacing: Use the actual expanded footprint, observed nighttime reach, current direction and future growth to set clearance. No fixed inch-based starting distance is verified as universally protective.

Corals to Avoid Nearby: Avoid close placement beside peaceful LPS corals, SPS colonies, zoanthids, soft corals, or any specimen within reach of its tentacles.

Compatibility

Fish Compatibility: Check the proposed fish's species-specific diet and behavior and observe the individual around this colony. A reef-safe sales label is not a guarantee; prevent persistent nipping, abrasion or physical displacement.

Invertebrate Compatibility: Assess the actual invertebrate's diet and behavior and secure the colony. Monitor food theft, irritation and displacement; a clean-up-crew or reef-safe label does not guarantee harmless contact.

Coral Compatibility: Mixed-reef suitability depends on the identified colonies' individual lighting, flow and growth needs plus separation from contact and defensive reach. Shared family or trade names do not establish safe touching or universal compatibility.

Potential Predators: Butterflyfish, some angelfish, filefish, and other known coral feeders; individual behavior varies

Potential Irritants: Clownfish hosting, fish perching, vermetid snail mucus webs, sediment, algae along exposed skeleton, stinging neighbors, and food-stealing invertebrates

Fragging & Propagation

Difficulty: Form- and specimen-dependent. Routine propagation of a healthy established colony is separate from treatment of unexplained tissue loss.

Propagation Method: Growers report captive fragmentation, but the appropriate method depends on species, form and healthy tissue layout. Obtain experienced form-specific advice; this guide does not prescribe cutting ahead of tissue loss as a universal rescue.

Tools/Method: Plan routine propagation with an experienced coral propagator, suitable tools, personal protection and containment of mucus, dust and spray. No cutting, antiseptic or dip is automatically indicated for a damaged or declining colony.

Healing: Keep any legitimately propagated fragment under stable, appropriately acclimated conditions and monitor attachment and tissue margins. Healing time and success vary; deterioration needs assessment rather than automatic repeated dips or cuts.

Special Risks: Handling, heat, crushing and torn tissue can damage a colony. Shared equipment or moving fragments can transfer unwanted organisms. Do not move apparently healthy pieces from a declining colony into another system as an assumed cure.

Safety Considerations: Use gloves and eye protection, protect skin cuts, contain mucus and skeletal dust or spray, and clean tools between colonies. Avoid improvised cutting of a deteriorating specimen; obtain experienced propagation or coral-health guidance.

Health & Common Problems

Tissue Recession: Record where tissue is missing, how quickly it changes and whether skeleton is exposed. Environmental instability, mechanical injury, contact damage, pests and infectious processes are possible, not diagnoses from appearance. Check measured conditions and recent changes; continued loss warrants qualified assessment.

Bleaching: Paling or whitening with tissue still present differs from bare skeleton after tissue loss. Heat and light stress are possible contributors, but appearance alone does not identify the cause. Verify conditions and recent exposure changes, correct confirmed problems cautiously and seek advice if deterioration persists.

Polyp Retraction: Retraction or deflation alone does not establish a cause. Compare with the colony's usual behavior, handling and light cycle; check measured conditions, flow, sediment, pests, injury and neighbor contact. Persistent closure with tissue deterioration warrants qualified assessment rather than automatic treatment.

Pests: Inspect actual tissue, margins, base and sheltered surfaces for organisms and damage, and identify suspected pests before treatment. Quarantine or separation can assist observation where safe. A dip is product-, coral- and pest-specific, not a universal cure; follow the exact current label and do not assume eggs or hidden pests are eliminated.

Diseases: Rapid or slow tissue loss, melting, or brown jelly-like material are observations, not proof of bacterial disease. Multiple environmental, physical, pest-related or infectious causes are possible. Document progression, verify measured conditions and obtain prompt coral-health or aquatic-veterinary guidance. Use safe matched-condition separation when practical; antibiotics, cutting, tissue removal and dipping are not universal or appearance-triggered treatments.

Signs of Stress: Prolonged retraction, a gaping mouth, unusual mucus, fading or bleaching, deflated tissue, exposed white skeleton, tissue peeling, or recession between heads

Common Keeper Mistakes: Strong direct flow, sudden lighting increases, unstable alkalinity or salinity, inadequate spacing, rough handling, allowing tissue to rub rock, and attempting to frag a wall colony like a branching colony

Recovery Considerations: Verify measured water conditions and recent changes, assess lighting, flow, injury, pests and neighbor contact, and correct confirmed problems cautiously. Avoid repeated moves or simultaneous large changes. Continuing or rapid tissue loss warrants prompt qualified advice; no automatic fragging, cutting, dipping or antibiotic protocol is prescribed.

Beginner Suitability

Beginner Friendly: Conditional on suitable measured marine conditions, gradual acclimation, growth space, observation and the ability to obtain qualified help; no uniform beginner-success guarantee is made.

Why: Prepare suitable measured conditions, acclimation, growth space and ongoing observation. Grower success in particular stock does not guarantee uniform hardiness or beginner success across the guide's stated scope.

Major Challenges: Providing observed stinging clearance, preventing tissue damage, identifying the growth form and obtaining prompt qualified advice for tissue loss.

Before You Buy

Important Considerations: Confirm whether the specimen is a wall or branching Frogspawn. Choose a colony with inflated tissue, no exposed skeleton at the tissue edge, no brown jelly-like material, and no active recession. Ask about the seller's lighting, salinity, and recent health history.

Space: Reserve a secure mounting point and a wide buffer around the fully expanded colony.

Lighting: Obtain the seller's measured lighting for the identified wall or branching specimen and ensure gradual adjustment is possible.

Flow: Use adjustable broad indirect movement and observe the expanded colony; pump power and low/moderate/strong labels alone do not define suitable exposure.

Aggression: Its sting can seriously damage nearby corals, even when the skeletons appear far apart.

Parameter Stability: Prepare an established, stable marine system with reliable monitoring appropriate to the actual colony and its neighbors. No trade-name-wide chemistry or detectable-nutrient threshold is established by this guide.

Long-Term Growth: Branching forms add new heads, while wall forms expand their continuous skeleton. Either can eventually require relocation or a larger defensive zone.

Species-Specific Information

Anything important that does not fit above: Frogspawn Coral is a common name rather than a single growth form. Fimbriaphyllia divisa is the wall form and Fimbriaphyllia paradivisa is the branching form; both were historically placed in Euphyllia. Correct identification is particularly important before fragging or treating tissue recession.

Related topics and compatibility

Similar Corals: Hammer Coral, Torch Coral, Cristata Coral, and other fleshy corals in Euphylliidae

Compatible Corals: Compatibility must be assessed for the actual colonies, with individual conditions, growth space and separation from observed contact or defensive reach; this is not a blanket safe-neighbor list.

Related Guides: Hammer Coral Care; Torch Coral Care; LPS Coral Placement; Reef Aquarium Lighting; Coral Acclimation; Stable Reef Water Parameters