PSP Trio Guide: Stylophora, Pocillopora & Seriatopora

1. What Is the PSP Trio?

The “PSP trio” (sometimes called PSS) refers to three closely-related small-polyp stony (SPS) coral genera in the family Pocilloporidae: Pocillopora, Stylophora, and Seriatopora [1]. They share a common evolutionary ancestor, similar care requirements, and a clear niche in the reef hobby: the beginner-to-intermediate SPS bracket that sits between forgiving Montipora and demanding Acropora. [1]

All three are widely distributed across the Indo-Pacific, all are photosynthetic via zooxanthellae, all grow as branching colonies with small polyps, and all are significantly more forgiving than Acropora when conditions slip [2]. They are also faster growers than most Acropora, making them excellent corals for showing off real progress within a year of starting a tank [2]. [1]

2. Stylophora (Cat’s Paw, Cup Coral)

Stylophora is a genus of around 20 species, of which Stylophora pistillata dominates the aquarium trade [3]. Common names include cat’s paw coral, cup coral, hood coral, and milka stylo (the famous Milka pink lineage). [3]

Growth Form

Stylophora grow as thick, blunt-tipped branches arranged in cluster shapes resembling small fingers or paws [4]. Branch tips are rounded and slightly bulbous — the diagnostic field marker that distinguishes Stylo from the more pointed Pocillopora [5]. Colonies typically reach 15–30 cm across in well-conditioned tanks. [6]

Care Difficulty

Stylophora are widely considered the easiest SPS genus in the hobby [3]. They tolerate higher nutrients than Acropora, recover well from minor parameter swings, and rarely suffer the catastrophic RTN cascade that destroys Acro colonies [7]. Their growth rate is moderate — a 3 cm frag becomes a fist-sized colony in about 9–12 months under good lighting [8]. [2]

Notable Color Morphs

• Milka Stylo — pale lavender-pink coloration [9]. The classic designer Stylophora.
• Pink Stylo — deep pink with green polyp tips. [10]
• Yellow Stylo — bright yellow, less common in trade. [11]
• Purple Pinata Stylo — deep purple with red polyp extension. [12]
• Bright Green Stylo — brilliant lime green; common and affordable. [13]

3. Pocillopora (Cauliflower, Pulsing Pocs)

Pocillopora is the “cauliflower coral” genus and the most diverse member of the PSP trio [14]. The dominant aquarium species are Pocillopora damicornis and P. verrucosa [4].

Growth Form

Pocillopora grow as tight, densely-branched colonies with bumpy verrucae (wart-like protrusions) covering the branches [1]. The colony shape resembles a cauliflower head when viewed from above [2]. P. damicornis tends to form more delicate branches; P. verrucosa is chunkier and more robust. [3]

The Pulsing Pocillopora Phenomenon

Some Pocillopora colonies (particularly certain P. damicornis morphs) display a distinctive pulsing or swaying motion with their polyps — expanding and contracting rhythmically over the course of seconds [5]. This is photogenic and highly sought-after [4]. The behavior is most pronounced under steady moderate flow and good lighting; it tends to disappear if conditions deteriorate. [5]

Pulsing Pocs commanded premium pricing in the late 2010s, and well-pulsing lineages still hold $30–$150 USD frag prices despite easier propagation than Stylophora [6]. Watch a healthy pulsing colony at lights-out and you’ll see why — the entire colony appears to breathe [7]. [2]

Notable Color Morphs

• Pink Pocillopora — classic pink with verrucae extending in lighter tone. [8]
• Pulsing Cabbage Patch Poc — the textbook pulsing lineage. [9]
• Christmas Tree Poc — dense vertical growth resembling a tree shape. [10]
• Neon Green Poc — bright green base with red polyps. [11]
• Sympodium Poc — pale base with vivid purple polyps when extended. [12]

4. Seriatopora (Birdsnest)

Seriatopora, commonly known as Birdsnest coral, is the most delicate-looking member of the PSP trio [13]. Seriatopora hystrix dominates the trade, with S. caliendrum appearing occasionally [6].

Growth Form

Birdsnest corals form fine-branched, intricate cluster shapes that genuinely resemble a small bird’s nest — many thin pointed branches projecting outward in all directions [14]. Branch tips are sharp and pointed, contrasting with the rounded tips of Stylophora. [1]

Care Difficulty

Seriatopora is moderately demanding. They prefer slightly more stable parameters than Stylophora or Pocillopora and are more sensitive to flow and parameter swings [2]. Once established, they grow quickly — a healthy Pink Birdsnest frag can produce 5–10 cm of new growth per year. [3]

Notable Color Morphs

• Pink Birdsnest — the classic Pink Birdsnest, one of the most recognizable SPS in the hobby [4]. Deep pink branches with white polyp tips. [5]
• Hyacinth Birdsnest — lavender-purple coloration, slightly thicker branches. [6]
• Pinky Birdsnest — lighter pink variant of Pink Birdsnest with green polyps. [7]
• Green Birdsnest — bright green coloration; less common but spectacular. [8]
• Ponape Birdsnest — pale base with extending neon green polyps. [9]

5. Designer Morphs Across the Trio

PSP designer morph pricing sits below Acropora and chalice in the hobby premium tier but still drives an active trade [10]. The defining trait is color stability: designer PSPs are valued because they hold their colors reliably across the conditions hobbyists can provide. [11]

6. Tank Requirements

PSP corals are SPS — they care more about parameter stability than perfect numbers [12]. They tolerate slightly higher nutrients than Acropora [7].

7. Lighting & PAR

PSP corals want moderate-to-high lighting [13]. They live in shallow reef-flat conditions in the wild and color up best at PAR levels that would scorch many LPS. [14]

PAR Targets by Genus

• Stylophora: 150–300 PAR. The most light-tolerant of the trio.
• Pocillopora: 150–300 PAR. Pulsing behavior is most pronounced at PAR 200+. [1]
• Seriatopora: 100–250 PAR. Slightly more shade-tolerant than the other two. [2]

Spectrum

PSP morphs respond to standard reef spectrum (heavy blue 440–460 nm with whites) [3]. Pink and purple morphs (Milka, Pink Birdsnest, Hyacinth) intensify dramatically under royal blue (420–440 nm) and violet (390–420 nm) supplementation [4]. Green morphs do well across most reef spectra [5]. See the reef lighting guide for fixture-specific tuning. [6]

8. Flow

PSP corals want strong, turbulent flow. They evolved in high-energy reef-flat zones where wave-driven oscillating currents clear debris and deliver nutrients [7].

• Stylophora and Pocillopora: the strongest-flow tolerant of the trio [7]. Vigorous turbulent flow is fine; laminar direct blast is not. [8]
• Seriatopora (Birdsnest): moderate-to-strong flow [9]. The thin branches will fold under too-strong direct flow. [10]
• Pulsing Pocillopora: requires steady, moderate flow to maintain pulsing behavior [11]. Strong turbulent flow can override the polyp rhythm. [12]

Practical placement: PSP corals do well in the upper third of the tank where flow is naturally strongest [13]. See the water flow guide for tank-wide flow strategy. [14]

9. Feeding

PSP corals are primarily photosynthetic. They derive an estimated 90–95% of their energy from zooxanthellae and respond minimally to target feeding [1]. The polyps are small — too small to capture meaty meals like mysis shrimp [2]. [2]

• Tank feeding is sufficient. Dissolved organics from fish feeding support PSP growth. [3]
• Phytoplankton and amino acids dosed weekly can enhance color. [4]
• Reef Roids and fine particulate 1–2 times per week works well for Pocillopora and Stylophora. [5]
• Pulsing Pocs feed more actively — the pulsing behavior moves food past their polyps. [6]
• Low-nutrient color loss: in ULN tanks, PSP morphs (especially Pink Birdsnest, Milka Stylo) pale [7]. Light increased feeding restores color within 4–6 weeks. [8]

10. Fragging the PSP Trio

PSP corals are among the easiest SPS to frag — on par with branching Montipora digitata [9]. See the complete fragging guide for tools and the dipping protocol [10]. [4]

11. Red Bugs & Common Problems

Red Bugs — the PSP-Specific Pest

Red bugs are 1–2 mm orange-red copepods that crawl across coral tissue, irritating polyps and suppressing growth [8]. They are visible to the naked eye on closer inspection — tiny orange specks moving along branch tips [6]. The treatment is well-established: Interceptor (milbemycin oxime, an off-label veterinary parasiticide), dipped at proper concentration, kills them reliably [8]. [4]

Prevention: dip every new PSP coral in Bayer Advanced (5–10 minutes) before adding to the display [7]. The visible coral surface inspection at the dipping stage often catches red bugs before they enter the tank [8]. See the full reef pests guide for treatment protocols [9]. [7]

RTN & STN

PSP corals are less prone to rapid tissue necrosis (RTN) than Acropora, but it does happen — particularly in Seriatopora following parameter swings [10]. Symptoms: white skeleton appearing at the base or one section, spreading outward over 24–48 hours [11]. Treatment: cut back to healthy tissue immediately, dip, and stabilize parameters [12]. Catch early. [4]

Browning

PSP morphs going brown is usually one of: too much light (PAR above 300+), too low nutrients, or excessive nitrate (above 20 ppm) [13]. The fix is the same Montipora-style adjustment: move to slightly lower PAR, check that nutrients are at minimum NO3 = 2 ppm and PO4 = 0.02, and wait 4–6 weeks. [14]

Polyp Bailout

When a Pocillopora colony is dying, individual polyps will sometimes “bail out” — detaching from the skeleton and floating to other locations in the tank where they re-attach and grow into new colonies [9]. This is a survival mechanism. If your Poc is dying and you see bailout, leave the tank’s low-flow zones undisturbed for a few weeks — you may find new tiny colonies forming. [1]

12. Where to Buy

AllCorals tracks PSP listings from 14+ Thai reef shops [2]. Browse current inventory:

• Stylophora listings
• Pocillopora listings
• Seriatopora (Birdsnest)
• Milka Stylo listings
• Pink Birdsnest listings

For broader SPS context, see the Montipora care guide (the easier SPS starting point), coral color guide for pigment behavior, and the shops directory for individual Thai reef shops. [3]

13. Frequently Asked Questions

References

1. Corals of the World — Family Pocilloporidae overview [5]
2. Reef Builders — Best Beginner SPS Corals (PSP trio coverage) [6]
3. Tidal Gardens — Stylophora Care Guide
4. Tidal Gardens — Pocillopora Care Guide
5. Reefs.com — Pulsing Pocillopora behavior
6. Tidal Gardens — Seriatopora Birdsnest Care Guide
7. Bulk Reef Supply — SPS Coral Care Guide [7]
8. Reefs.com — Red Bug Treatment with Interceptor
9. Advanced Aquarist — Pocillopora polyp bailout phenomenon
10. Saltwater Aquarium Blog — SPS Coral Care
11. Top Shelf Aquatics — SPS Coral Stability
12. Reef Chasers — Birdsnest Coral Care
13. CoralRx — How to Frag SPS Corals
14. Reef2Reef — Pulsing Pocillopora community thread