The Breeder’s Registry©Information contained in this report is taken from submitted observations from aquarist unless noted otherwise (see comments). Information may be reproduced providing the Breeder’s Registry is cited.

Breeder ID: TRISQA-011093-JACLAR-001

Date received: 1/10/93

Identification: Tridacna squamosa (Lamarck, 1819)

Geographic origin: Indo-Pacific

Taxonomy: (after I.C.Z.N.)

Kingdom Animalia

Phylum Mollusca

Class Bivalvia

Order Veneroidea

Family Cardiacea subfamily Tridacnidae

Genus Tridacna

Species squamosa (Lamarck, 1819)

Description: 30 cm in shell length (occasionally 40 cm). The shells possess rows of “scales” (from which the name is derived ; squama = scale) which run parralell to the rim to the bottom of the shell. The denser the shell at the upper rim, the longer and wider they are. The shell may be white with a yellow band at the rim, or completley yellowish with orange spots. Occasionally the entire shell is orangish to pinkish in color. The mantel is usually speckled in color which can include blue, green, brown, yellow and orange. Found on coral reefs to depths of 18 meters

Duration (yr): 0.2

Size (mm): 279

Broodstock notes: gonochoristic. Fertilization is external (broadcast spawners0

Adult diet: endosymbiosis with Symbiodinium micriadriaticum

Time spawning began: 1800 – 2100 hours

Area spawning occurred: Specimen was 30 cm below surface

Frequency of spawning: only release observed

Egg description: Discharges were very strong; first sperm, then eggs at approximately one minute intervals.

Approximate quantity: unknown

Egg changes / development: unknown, removed by filtration

Incubation period: unknown

Spawning tank size (liter):756

Sides of tank covered? Yes, back- blue

Lighting & photo-period: Metal halide and actinic (12 hours)

Filtration: Wet / dry, skimmer, ozone with controller

Additives and dosages: calcium, strontium, iodide

Water temperature: 75 F

Specific gravity: 1.024

pH: 8.3

Nitrate: 4.4 ppm

Comments: Tridacna maxima (152 mm) began spawning approximately 1 hour after T. squamosa. Discharge less frequent, but similar to T. sqaumosa.

Word origin: The genus Tridacna is from the Latin word Tri meaning three (3), and dacn from the Greek word meaning bite or sting. The species squamosa from the Latin word squam, =a, -at, -i, -o, meaning a scale and Latin root -os, =a, =um, =us, meaning full of. Thus, Tridacna squamosa could be translated to mean “three bites full of scales”. The “three bites” referring to the tooth pattern of the zig-zag mating of the two shells, and “full of scales” referring to the ridge-like scales covering the exterior of the shell.

Suggested references:

Knop, Daniel, Giant Clams: A Comprehensive Guide to the Identification and Care of Tridacnid Clams, 1996, Dähne Verlag GmbH, Germany, hardbound, 255 pages, ISBN 3-921684-23-4

Delbeek, J. Charles, & Sprung, Julian, The Reef Aquarium: A Comprehensive Guide to the Identification and Care of Tropical Marine Invertebrates, 1994, Ricordea Publishing, USA, hardbound, 544 pages, ISBN 1-8836393-12-8

About this report: Information contained in this report is taken from submitted observations. Taxonomy, Synonomy, Original description , Word origin and Suggested reading are provided by member(s) of The Breeder’s Registry staff. Information is presented under the belief that it is accurate. If you have information in addition to, or contrary to that presented you are encouraged to contact the Breeder’s Registry. Permission is granted for “one-time” personal use. Reproduction as distributed or accessible media is prohibited without prior written permission. All rights reserved. 1993