The Sapphire Sentinel Free Pattern – Crochet a Betta Fish in a Jar

Bring the serene beauty of a betta fish into your home with this cozy, crocheted aquarium-in-a-jar. The intricate fin textures and jewel-toned palette make it a stunning, yarn-based centerpiece that captures the graceful movement of a betta without any of the upkeep. This amigurumi project is perfect for intermediate beginners who want to stretch their skills with layered fins, color changes, and a clever jar construction that doubles as a display case.

Whether you're looking for a unique gift for a fish lover, a whimsical shelf decoration, or a satisfying weekend project, this pattern delivers. The finished piece measures approximately 5-6 inches tall, making it an ideal desk companion or mantelpiece accent. Let's dive into creating your very own Sapphire Sentinel!

Materials Needed

Before you begin, gather the following supplies. All yarn should be worsted weight (category 4) for best results:

• Yarn colors:
  • Sapphire blue (body of fish) – approximately 50g
  • Coral red (fins) – approximately 30g
  • Clear/light blue (jar and water) – approximately 60g
  • Darker blue (water depth gradient) – small amount
  • White (eyes) – small amount
  • Black (pupils and mouth) – small amount
  • Cream or warm wood tone (lid) – approximately 20g
  • Green (optional plant decoration) – small amount
• Hook: 3.5mm (E) crochet hook
• Yarn needle for weaving ends and assembly
• Stitch markers to track rounds
• Polyester fiberfill for stuffing
• Scissors

Gauge: 4 sc x 4 rows = 1 inch. Gauge is not critical for amigurumi, but keeping consistent tension throughout will ensure your pieces fit together properly.

Step-by-Step Instructions

This pattern creates a fully crocheted betta fish nestled inside a crocheted jar, with a removable lid for display. Work in continuous rounds unless stated otherwise. Use a stitch marker to track rounds – this is essential for amigurumi work.

Part 1: The Jar

Bottom and Body (make 1)

With clear/light blue yarn:

• Rnd 1: Make a magic ring, 6 sc in ring. (6)
• Rnd 2: 2 sc in each st around. (12)
• Rnd 3: (sc in next st, 2 sc in next st) around. (18)
• Rnd 4: (sc in next 2 sts, 2 sc in next st) around. (24)
• Rnd 5: (sc in next 3 sts, 2 sc in next st) around. (30)
• Rnd 6: (sc in next 4 sts, 2 sc in next st) around. (36)
• Rnd 7: (sc in next 5 sts, 2 sc in next st) around. (42)
• Rnd 8: Working in back loops only, sc in each st around. (42) – This creates a flat base edge that will help the jar sit upright.
• Rnds 9-18: Sc in each st around. (42) – This forms the main jar body.
• Rnds 19-20: Switch to darker blue yarn. Sc in each st around. (42) – This suggests water depth at the bottom of the jar.
• Rnd 21: Switch back to clear/light blue. Sc in each st around. (42)

Shaping the Top of the Jar

• Rnd 22: (sc in next 5 sts, sc2tog) around. (36)
• Rnd 23: (sc in next 4 sts, sc2tog) around. (30)
• Rnd 24: (sc in next 3 sts, sc2tog) around. (24)
• Rnd 25: (sc in next 2 sts, sc2tog) around. (18)
• Rnd 26: (sc in next st, sc2tog) around. (12)
• Rnd 27: sc2tog around. (6)

Fasten off, leaving a long tail. Thread the tail through a yarn needle and weave it through the front loops of the remaining 6 stitches. Pull tight to close the opening, then secure and weave in the end.

Pro tip: Before closing the top completely, you may want to insert the fish and any decorations. However, the pattern works best if you close the jar top and access it through the lid instead.

Part 2: The Jar Lid

With cream or warm wood tone yarn:

• Rnd 1: Make a magic ring, 6 sc in ring. (6)
• Rnd 2: 2 sc in each st around. (12)
• Rnd 3: (sc in next st, 2 sc in next st) around. (18)
• Rnd 4: (sc in next 2 sts, 2 sc in next st) around. (24)
• Rnd 5: (sc in next 3 sts, 2 sc in next st) around. (30)
• Rnd 6: (sc in next 4 sts, 2 sc in next st) around. (36)
• Rnd 7: (sc in next 5 sts, 2 sc in next st) around. (42)
• Rnd 8: Sc in each st around. (42)
• Rnd 9: Working in back loops only, sc in each st around. (42) – This creates a rim that will fit snugly over the jar opening.
• Rnd 10: Sc in each st around. (42)

Fasten off, leaving a long tail for sewing. You have two options:

• Option A (Permanent): Sew the lid directly to the top opening of the jar.
• Option B (Removable): Leave the lid separate for access. Add a small crocheted handle: chain 10, slip stitch back along the chain, and attach to the center of the lid for easy lifting.

Part 3: The Betta Fish

Body (make 1)

With sapphire blue yarn:

• Rnd 1: Make a magic ring, 6 sc in ring. (6)
• Rnd 2: 2 sc in each st around. (12)
• Rnd 3: (sc in next st, 2 sc in next st) around. (18)
• Rnd 4: (sc in next 2 sts, 2 sc in next st) around. (24)
• Rnd 5: (sc in next 3 sts, 2 sc in next st) around. (30)
• Rnds 6-10: Sc in each st around. (30) – The body grows here. Keep your tension even for a smooth shape.
• Rnd 11: (sc in next 3 sts, sc2tog) around. (24)
• Rnd 12: (sc in next 2 sts, sc2tog) around. (18)
• Rnd 13: (sc in next st, sc2tog) around. (12)
• Rnd 14: Sc2tog around. (6)

Before closing, stuff the body firmly with fiberfill. The betta should feel plump and solid, not squishy. Fasten off, leaving a long tail. Thread through the front loops of the remaining 6 stitches, pull tight, and secure.

Tail Fin

With coral red yarn, attach yarn to the back end of the body (opposite where the head will be). This is the most dramatic part of the betta, so take your time:

• Chain 10, then work: 2 dc in 3rd ch from hook, 3 dc in next ch, 2 dc in next ch, 1 dc in next ch, 1 hdc in next ch, 1 sc in next ch, slip stitch in last ch.
• Fasten off.
• Repeat this process 3-4 times around the back edge, spacing them evenly to create a flowing, multi-layered tail.

Alternative method: Crochet a separate fan-shaped piece and sew it onto the back. To do this: chain 12, work 2 dc in 3rd ch from hook, 3 dc in next ch, 2 dc in next ch, 1 dc in next 2 ch, 1 hdc in next 2 ch, 1 sc in next 2 ch, slip stitch in last ch. Make 2-3 of these and layer them.

Dorsal Fin (top of fish)

Attach coral red yarn to the top of the body, along the ridge:

• Chain 8, then work: 2 dc in 3rd ch from hook, 2 dc in next ch, 1 dc in next ch, 1 hdc in next ch, 1 sc in next ch, slip stitch in last ch.
• Fasten off.
• Repeat 2-3 times along the top ridge, spacing them evenly from the head area toward the tail.

Pectoral Fins (sides)

Make 2 small pieces:

• With coral red yarn, chain 5.
• Work 1 sc in 2nd ch from hook, 1 hdc in next ch, 1 dc in next ch, 1 dc in last ch.
• Fasten off, leaving a tail for sewing.
• Sew to the sides of the body near where the head will be, angling them slightly downward for a natural swimming pose.

Eyes

With white yarn:

• Make a magic ring, 6 sc in ring. (6)
• Fasten off, leaving a tail.
• Sew onto the head area, positioning them on either side of the face.

With black yarn, embroider a small French knot or stitch in the center of each white circle. Alternatively, use 6mm safety eyes if you prefer – just insert them before closing the body.

Mouth

With a small piece of coral red yarn, embroider a tiny smile or open mouth shape on the front of the head. Use a simple backstitch or satin stitch to create a curved line.

Part 4: Water and Decor (Optional)

Bubbles

To simulate water, crochet a few small bubbles:

• With clear/light blue yarn, make magic rings of 4-6 sc each.
• Fasten off, leaving a tail.
• Sew inside the jar around the fish, spacing them at different heights.

Plant

Add a small crocheted plant for extra charm:

• With green yarn, make a chain of 10.
• Work 3 sc in each ch, forming a wavy leaf.
• Make 3-4 leaves and sew to the bottom of the jar.

Part 5: Assembly

Now for the fun part – bringing it all together!

1. Position the fish: Place the betta fish inside the jar, positioning it so the tail fin faces the back and the head faces the front. The fish should appear to be swimming upward or forward.
2. Secure the fish: Use a few stitches to secure the fish to the bottom of the jar if desired. This prevents it from shifting during display.
3. Add decorations: Place the water bubbles and plant around the fish, arranging them naturally.
4. Attach the lid: Place the lid on top, or sew it in place for a permanent display. If using the removable option, the handle makes it easy to lift.
5. Finish: Weave in all ends carefully. Block if needed to shape the fins – a light misting with water and gentle finger-shaping works well for acrylic and cotton yarns.

Tips for Success

• Stitch markers are your friend: Amigurumi is worked in continuous spirals, so without markers, it's easy to lose your place.
• Stuff as you go: For the fish body, stuff firmly before closing. For the jar, you don't need to stuff it – it should hold its shape on its own.
• Fin placement: Take time to arrange the fins attractively. The multi-layered tail is what gives this betta its dramatic, flowing look.
• Color changes: When switching yarn colors, work the last yarn-over of the previous stitch with the new color for a seamless transition.
• Customize: Feel free to experiment with different color combinations – a purple betta with teal fins would be stunning, or a golden betta with orange fins for a warm palette.

Your Sapphire Sentinel is now complete! This charming piece makes a wonderful gift, a unique conversation starter, or a beautiful addition to your own cozy space. The soft, plush texture invites touching, and the intricate fins showcase your crochet skills beautifully.

Happy crocheting, and may your yarn always be tangle-free!